Experiment results by EUN Partnership aisbl

Marjeta, Slovenia Experiment with yeast and different concentration of suger.

marjeta_decman — 2018-03-13 09:43:39 UTC

Experimental material:

Making yeast suspension: (200 ml warm water + 14 g dry yeast)

Dosing of 30 ml of yeast suspension:

Making different concentration of suger solution (1. (left) contol - no suger, 2. yeast suspension + 5 g of suger, 3. yeast suspension + 10 g of suger; 4. yeast suspension + 30 g of suger; 5. yeast suspension + 60 g of suger)

Experiment after 5 minutes:

Experiment after 10 minutes:

Experiment after 15 minutes:

Experiment after 30 minutes:

Difficulties while experimenting:
1. The balloons must be pre-filled with air so that the rubber becomes more flexible.
2. All Erlenmeyer flasks were not of the same size.
3. The quantity of gas produced in the 2nd and 3rd Erlenmeyer flasks does not differ in the size of the balloon (the balloon with the added quantity of sugar 5 g is harder).

Control is used, one variable has been introduced (suger), concentration of yeast is same in all flasks.

There is no yeast activity where si no added sugar and where is a lot of added sugar.

Sugar is a source of yeast, gives the bread and cakes a better taste and the bark is faster in color brown. If there is a lot of sugar in the dough, it is necessary to put the yeast.

jagodalakovic — 2018-03-13 14:27:05 UTC

jagodalakovic — 2018-03-13 14:27:58 UTC

jagodalakovic — 2018-03-13 14:30:28 UTC

Agnieszka - Poland

2018-03-13 16:20:50 UTC

No sugar no fun

Agnieszka - Poland

2018-03-13 16:24:20 UTC

It is sugar is gas

Ana, Spain

anamarialorentegarcia — 2018-03-13 16:52:04 UTC

A growing medium with sugar suppose a most grow activity of yeast.
Difficulties:

The glass used was too big for the baloon, so at the end I decided use a bottle.

Nicola, Malta

nixy_port — 2018-03-13 20:44:26 UTC

I really enjoyed experimenting quietly in the comfort of my school laboratory and I had all the apparatus and materials needed so no difficulties as such were experienced. The picture below was taken 1 hour after the experiment was set up:
Test tube 1 - only contained distilled water
Test tube 2 - contained 20% sugar solution
Test tube 3 - contained 50% sugar solution
Test tube 4 - saturated sugar solution.

The yeast only seemed to be respiring in the 20% sugar solution however after 2 hours passed, test tube 1 and 3 also slightly inflated. I wasn't expecting the test tube 1 to inflate since no sugar was present. However it could be that the yeast was respiring using its food stores.

PaolaCB, Italy

paolacannadabartoli — 2018-03-14 13:16:23 UTC

SinceI had few material at home, I could do just 3 dilution of sugar. To check powdered yeast worked I add pure sugar to the suspension

2018-03-14 13:56:51 UTC

Francesco PIccolo/Italy

Alex, Austria

2018-03-14 14:57:33 UTC

Hypthesis:
The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gaz they produce.
Result: The result says clearly yes: without sugar there is no activity, but there is more activity with less sugar, than with a high amount of sugar - so there have to be further investigation to explain that facts

Silvia, Spain

2018-03-14 16:24:47 UTC

I put the same amount of water and yeast in 5 Erlenmeyer flasks. I added 0, 1, 2, 3 and 4 g of sucrose. I controlled what happened after 30 minutes and 60 minutes. For these quantities of water and yeast the flask containing 2 g of sucrose was the one that showed a higher level of fermentation. There were no signs of activity in the flask without sucrose.

Michael, Ireland.

collabscience — 2018-03-14 16:40:04 UTC

Took the opportunity to do this today with first year students. We added 2 g yeast and 15 ml water to each test tube,
tube A got no sugar,
tube B got 1 g,
tube C got 2 g and
tube D got 3 g.
All placed in a beaker of warm water for 20 minutes and here is our result...
Advance prep is important. Make sure you have enough balloons, spoons, weighing scales and sugar.

Mitko, Macedonia

miticko — 2018-03-14 16:43:28 UTC

Testing hypothesis: The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time.
For this experiment I use 4 flasks. In the first one I pour only water and 4 g. of dehydrated yeast. this was the control. In the second flask I pour water, 4 g. dehydrated yeast , and 4 g. sucrose. In the third flask I put 4 g. of dehydrated yeast, water and 8 g of sucrose, and in the fourth flask i put water, 4 g. of dehydrated yeast and 24 g of sucrose. Then I covered the flask with balloons.
As expected content of sugar affects the level of activity of yeast in a given time. In first flask ( control) there was no gas production, in the second there was main yeast activity, in the third there was gas production but in a much lower rate, and in the last flask with concentrated sugar dilution there was no gas production at all after 30 min.

Andrea Checchetti

2018-03-14 19:49:31 UTC

Protocol in order to test the hypothesis

Required material:

three test tubes
three colored balloons

Reagents

1 yeast cube
water
sugar

Protocol:

tube tube 1: water + brewer's yeast (green balloon)
test tube 2: water + sugar (yellow balloon)
test tube 3: water + yeast + sugar (red balloon)

Results

The development of carbon dioxide as a product of sucrose fermentation is observed only in the tube 3

Alice, Italy

severi_alice — 2018-03-14 20:29:36 UTC

My experiment testing hypothesis that yeast and sugar are influenced also by temperature of water.
1st test tube: water 0°C+yeast+sugar; 2nd test tube: control;
3rd test tube:water 40°C+yeast+sugar; 4th test tube control;
5th test tube:water 100°C+yeast+sugar; 6th test tube:control.
Conclusion: 3rd test tube has produced the most quantity of gas. Water at 0°C and 100°C inhibit yeast activity.
1) Difficulties are encountered in putting ballons on test tube more rapidly than the reaction goes.
2) My question is on different type of yeast. It would be interesting to make an experiment to compare different kind of yeast.

Aleksnadra Blazevska, Macedonia

prof_acka — 2018-03-14 22:18:51 UTC

Hypothesis: Concentration of sugar affects of the activity yeast, less concentrate more active yeast, larger amount of carbon dioxide is produced.
Required materials:
Dry yeast, sugar, distillate water, 6 balloons, 6 testing tubes.
1. Testing tube put 50ml distillate water + 1g yeast + red Balloon
2.Testing tube put 100ml distillate water + 1g yeast + 5g sugar + orange Balloon
3. Testing tube put 50ml distillate water + 1g yeast + 10g sugar + yellow Balloon
4. Testing tube put 50ml distillate water + 1g yeast + 15g sugar + green Balloon
5. Testing tube put 50ml distillate water + 1g yeast + 20g sugar + blue Balloon
6. Testing tube put 50ml distillate water + 1g yeast + 25g sugar + indigo Balloon
Observations after 5 hours
Conclusion: The biggest activity of yeast after 5 hours is noticed at concentration of 10% of sugar , then 20% of sugar. At concentration of sugar of 50 % there is no noticed
activity

Lucia G. - Italy

2018-03-15 14:10:02 UTC

Hypothesis. The concentration of sugar affects the development of yeast cells: low concentrations behave as a substrate while higher concentrations inhibit its development due to the higher osmotic ambient pressure.
Required materials: 7 test tubes, yeast, syrup of sugar, 7 balloons, water.
Method: prepare the syrup (100g / 150ml of water) and active the yeast in 150 ml of water.
I prepare 7 tubes with 10 ml of water suspension and yeast and increasing quantities of syrup. The total volume is brought to 15 ml.
After 2 hours in the 3 test tubes with the minimum quantity of sugar the gas production was observed. Then the hypothesis made at the beginning has occurred

Chiara G. Italy

chiara_garulli — 2018-03-15 16:07:26 UTC

The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time.

To test this hypothesis I prepare 5 samples containing:
1) 4ml of water
NEGATIVE CONTROL
2) 4ml of a 10% sucrose solution
SAMPLE1
3)4ml of a 40%sucrose solution
SAMPLE2
4) 4ml of a 70% sucrose solution
SAMPLE3

2ml of the same yeast suspension is added to each sample.

I put a balloon on the test tube in order to visualize produced gas.
In this way I will obtain only qualitative data.
I will try to measure the gas produced repeating the same procedure but using particular homemade tube

PALMA from Spain

2018-03-15 19:46:20 UTC

Protocol in order to test the hypothesis.
Material:
5 tubes
Five balloons
Mi real water
Sugar
Yeast.
The process:
Five tubes with water and one tea spoon of yeast.
Number 1= 1 tea spoon of sugar.
Number 2= 2 tea spoon of sugar
Number 3= 3 tea spoon of sugar.
Number 4= 4 tea spoon of sugar
Number 5= 0 tea spoon of sugar

Daria, Poland

2018-03-15 21:23:35 UTC

HYPOTHESIS:
The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time.
I prepare 5 samples:
1) 5 ml water, 1 g yeast
2) 5 ml water, 1 g sugar, 1 g yeast
3) 5 ml water, 2 g sugar, 1 g yeast
4) 5 ml water, 3 g sugar, 1 g yeast
5) 5 ml water, 4 g sugar, 1 g yeast.
I took photos in ten -minute intervals.

Daria, Poland

2018-03-15 21:29:37 UTC

after 10 minutes

Daria, Poland

2018-03-15 21:31:28 UTC

after 20 minutes

Daria, Poland

2018-03-15 21:34:11 UTC

after 30 minutes

Daria, Poland

2018-03-15 21:35:53 UTC

after 40 minutes

Pilar, Spain

2018-03-15 21:45:33 UTC

Protocol:
a control tube with water and yeast, three tubes with water, the same amount of yeast in the control and increasing amounts of sugar in each tube.

Resutls:
In the pipes 2 and 3 there is fermentation, with the release of gas. In the tube 4 there is no activity, as the yeast die.

It is an experiment so easy, and students love it.

Sophie, Austria

2018-03-15 23:12:15 UTC

Sophie, Austria

2018-03-15 23:14:56 UTC

I made this video after 60 minutes.
(10 minutes with time lapse)

Poonam, India

2018-03-16 06:22:13 UTC

Gas formation by yeast is depend on sugar concentration; Use of different concentration of sugar leads to formation of variable quantity of gas.

munir ghanem , israel

ghmunir29 — 2018-03-16 11:26:48 UTC

hypothesis: the activity of yeast icreases when the sugar concentration is high, so the carbon dioxide formation increases accordingly.experiment protocol:
1.4 bottles with 5 gr of dry yeast, at room temperature 18 c.
2. bottle number 1 contains only water.
3.bottle number 2 contains 0.14 M sucrose solution .
4.bottle number 3 contains 0.7 M sucrose solution .
5.bottle number 4 contains 0.35 M sucrose solution .
6.All 4 bottles covered up by same baloons.
7. time scaling after 10,20,30,40 minutes took photo for all bottles .

Nina, Slovenia

2018-03-16 13:11:23 UTC

The results after 5 minutes:

A 0,5 g of baking powder + 1g sugar and 5 ml of Mineral Water

B 1 g of baking powder + 1g sugar and 5 ml of Mineral Water

C 1,5 g of baking powder + 1g sugar and 5 ml of Mineral Water

D 2 g of baking powder + 1g sugar and 5 ml of Mineral Water

Tina, Austria

2018-03-16 16:32:52 UTC

Materials: dry yeast, sugar, distilled water, balloons, equivalent test tubes

1^st tube: violet balloon, 5 ml distilled water, 1.75 g dry yeast

2^nd tube: red balloon, 5 ml distilled water, 1.75 g dry yeast, 8 drops fluid sugar (= 1 teaspoon sugar)
3^rd tube: green balloon, 5 ml distilled water, 1.75 g dry yeast, 12 drops fluid sugar
4^th tube: yellow balloon, 5 ml distilled water, 1.75g dry yeast, 16 drops fluid sugar
5^th tube: blue balloon, 5 ml distilled water, 1.75g dry yeast, 20 drops fluid sugar

I took pictures every hour.

Tanja, Austria

2018-03-16 17:33:59 UTC

I wrote it down like we used to do it at university with all my actions and results.

Voinea-Axinte Costica

2018-03-16 18:08:12 UTC

Experiment: water - yeast - sugar
I did not encounter any difficulty during the experiment. It was just that balloon 2 was the one who reacted the fastest. At the end of the experiment, balloons 2, 3 and 4 had about the same volume of gas removed.

Elena, Italy

2018-03-16 18:40:56 UTC

Helen Mihalatou, Greece

2018-03-16 21:02:25 UTC

Helen Mihalatou, Greece

helensefer — 2018-03-16 21:11:18 UTC

Testing hypothesis: The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time.
As expected, the content of sugar seems to affects the level of activity of yeast in a given time. In the control tube there was nearly no gas production, in the second and third tubes there were main yeast activity (higher sugar content), in the fourth and fifth tubes the gas production rate was lower after 1 hour (highest sugar content).
Difficulties while experimenting:
1. The rubber of the balloons were not so flexible.

2. The time needed to put the balloons on the test tubes (gas was being produced while I was trying to put the balloon on tube no 3).

3. We cannot measure the difference in the rate of gas production between tubes 2 and 3.

4. There was some gas produced in the control test tube (no added sugar).

Milijana, Sebia

2018-03-16 21:48:14 UTC

I concluded that sugar accelerated the fermentation and that where I added most sugar, there was a release of gas.

Doinita B., Romania

2018-03-16 22:37:23 UTC

My experiment was succesfully!

Barbara, Poland

2018-03-17 12:54:09 UTC

The course of the experiment:
1. 1 flat teaspoon of sugar + top up with H2O to 40 ml + 1 teaspoon of yeast.
2. 2 flat teaspoons of sugar + make up to 40 ml with water + 1 teaspoon of yeast.
3. 3 flat teaspoons of sugar + make up to 40 ml with water + 1 teaspoon of yeast.
4. 4 flat teaspoons of sugar + make up to 40 ml with water + 1 teaspoon of yeast.
5. Control: 40 ml of water + 1 teaspoon of yeast.
Photographic documentation: start, one, two, three and four hours.
Pictures later.

Ayşe ARSLAN, Turkey

aysekaraul — 2018-03-17 13:07:30 UTC

My experiment gived different result from my hypoteses.

Maria Z.

mariazambrotta68 — 2018-03-17 13:39:59 UTC

I made the experiment:
-flat A
10 g of sugar + 50 mL water + 1 g yeast
-flat B
- 20 g sugar + 50 ml water + 1 g yeast
-flat C
30 g sugar + 50 ml water + 1 g yeast
-flat D
50 ml water + 1 g yeast

the production of gas increase with the amount of sugar.

Dario, italy

pd_dario — 2018-03-17 15:02:13 UTC

my yeast experiment ;)

Vesna, Slovenia

2018-03-17 15:17:20 UTC

Materials: dry yeast, sugar, warm water, 6 baloons, 6 test tubes.
I put the same amount of water and yeast in each test tube, except the control tube (marked K), where I only put water and yeast. In test tube no. 1. I 1/4 of ateaspoon, in no. 2. 1/2 of a teaspoon, in no. 3. 1 teaspoon, in no. 4. 1,5 teaspoon and in no. 5. I put two teaspoons of sugar. After 4 hours I observed the results

Klara, Vienna

2018-03-17 17:59:40 UTC

Sonja, Croatia

sonja_pospisil77 — 2018-03-17 21:17:06 UTC

2018-03-17 21:47:27 UTC

I made the experiment according to the following protocol. I made a suspension of yeast (25 g in 300 ml of water + 1 hour rest) and a solution with saccarose. Then I made 4 different vials with 5 ml of suspension each + A 0 ml of sugar, B 0,5 ml of sugar, C 1,5 ml of sugar , D 2,5 ml of sugar. The result is shown in the picture. I had visible changes in vials B and C. Undortunately the vials were too smal so I wasn't able to have a vial with the grow of yeast affected by an excess of sugar

Barbara, Poland

2018-03-17 23:04:28 UTC

1. Documentationof results /pdf/
2. Doubts:
- too few research attempts to confirm or deny the hypothesis,
- accuracy of dosing ingredients

Jana, CZ

jjilkova — 2018-03-18 00:14:40 UTC

Protocol:
Materials: 3 test tubes
3 ballons
2 bags of yeast (2,5g)
3x 15 ml of water
Process:
10ml water + 2,5 g yeast put into each of the tubes
added suggar:
T1 + 1 teaspoon of suggare
T2 + 1/2 teaspoons of suggar
T3 + 1 no suggar
Testtubes were left in 25C
The ballon on T3 has not changed
Ballons on T1 and T2 inflated.
Solution: gas produced by the yeast which grow more with suggar added inflated the ballons

Tanja, Slovenia

brinje_raziskovalci — 2018-03-18 08:45:54 UTC

Protocol:
4 test tubes, 4 bags of dryed yeast, 20 bags of sugar (5g each), 400 mL cold water, 4 baloons.
Every test tube has 1 bag of yeast and 100 mL water:
1) no added sugar
2) 2 bags of sugar
3) 6 bags of sugar
4) 12 bags of sugar,
I shake every tube for 3 minutes, put on a baloon, leave on the room temperature for 60 minutes (observations every 10 minutes).
Difficulties:
water temperature was lower in third test tube by accident - not appropiate results.
not enough suggar to stop yeast activity (less then 55%).
Results (first test tube - flat balloon - is not on the picture; position of test tubes: 4,3,2)

Philipp, Austria

2018-03-18 10:03:55 UTC

Materials:
10 bottles (500ml), 10 ballons, about 15g (2 packages) of dried yeast, water and syrup.

Process: first I labled the bottles. first bottle got number 0, second bottle 0T, third bottle, 10, forth 10T, the fifth bottle got 30, the sixth 30T, seventh 50, eighth 50T, ninth 70, tenth 70T.
The numbers mean the percentage of sugar in the bottle. for example "10" means, that the bottle contains about 10% of syrup. (of 50ml is about 5ml syrup, 3g yeast and all the rest water.
T means the controlling group, without yeast in it, just syrup and water.

Next step is to give 3g of yeast in every bottle (without the bottles with "T")
Then I measured the syrup and the water with a syringe and give it inside the bottle. After all I put the ballon over each bottle.
then I wait.
First picture is about 30minutes after the begin.
Second picture is about 1 hour after.
And third picture is about 1 1/2 hours after starting.

"The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time."

I really agree with this hypotese, because my experiment shows the effect of sugar in a medium of yeast.
If it's too "sweet" for yeast, it would not grow. The bottle with 10% and 30% sugar grow most, the other not this much. The bottle with 70% sugar does not grow.

So the hypotese is correct.

Viktorija, Slovenia

2018-03-18 11:28:18 UTC

Materials:
8 tubes, 8 balloons, 9g baking powder, 9g sugar, mineral water.

Process:
First I took 4 tubes and filled them with the same amount of mineral water and sugar, I changed the quantity of baking powder.
Tube 1: 0,5g of baking powder, 1g of sugar, 5ml of mineral water
Tube 2: 1g of baking powder, 1g of sugar, 5ml of mineral water
Tube 3: 1,5g of baking powder, 1g of sugar, 5ml of mineral water

Tube 4: 2g of baking powder, 1g of sugar, 5ml of mineral water
The results after 5 minutes: see the picture with green balloons.

Then I took the remaining 4 tubes and filled them with the same amount of mineral water and baking powder, changing the quantity of sugar.
Tube 1: 0,5g of sugar, 1g of baking powder, 5ml of mineral water
Tube 2: 1g of sugar, 1g of baking powder, 5ml of mineral water
Tube 3: 1,5g of sugar, 1g of baking powder, 5ml of mineral water

Tube 4: 2g of sugar, 1g of baking powder, 5ml of mineral water
The results after 5 minutes: see the picture with colorful balloons.

Aleksandra, Poland

kwiekola — 2018-03-18 11:30:28 UTC

Gilda/Italy

2018-03-18 11:52:24 UTC

Material:

3 test tubes

3 ballons

3 x 15 mL of water

3 x 2 g of veast

6 g of sugar

Procedure:

Put in tubes (1, 2, 3) 15 mL of water with 2 g of yeast

Put 2 g of sugar in tube 2

Put 4 g of sugar in tube 3

Put a ballon on each tube ( 1, 2, 3)
Conclusion:

the quantity of sugar influence yeast’s activity. Yeast cells are more active if there is more sugar.

I didn’t come across any difficulties while experimenting but I had a doubt about the quantity of each ingredient.
In the following file there are some pictures.

Protocol:

2018-03-18 14:55:43 UTC

materials,:
Baker's yeast, mineral water, sucrose (table sugar)
5 conical flasks
5 baloons
procedure
to each flask add 50 ml of water and 1g of Baker's yeast, then to the 1st baker add one spoon of suger, to the 2nd baker ad two spoons of sugar and so on. Then mix thorougly and put a balloon on each flask. Obsserve for a while.

Eduardo, Spain

2018-03-18 17:08:04 UTC

Protocol:

Put 200ml of water in each of 3 bottles.
Put a spoonful of yeast in each bottle
Put 1g of sugar in the second bottle and 5 g of sugar in the third one.
Put a ballon on top of each bottle as a lid (different colours)
wait 1h to see the final result.

Results:

the balloon in the bottle without sugar did not experiment any inflation.
The balloon in the bottle with 1g of sugar suffered a little inflation.
The balloon with 5g of sugar experimented the biggest inflation.

Conclusions:

The quantity of sugar is plays an important role in the yeast activity.

Difficulties:

Find test tubes, so I used bottles of water instead.

Doubts or questions:

How much of each ingredient do I need?
How much time do I need to wait?

Lucia, Romania

2018-03-18 17:21:34 UTC

I think that sugar accelerated the fermentation. Students love this experiment.

Izabela, Poland

2018-03-18 17:53:59 UTC

I've done the experiment using 6 tubes with 5 ml of water and 1 g of yeast.
tube 1: no sugar
tube 2: 1 g of sugar
tube 3: 2 g of sugar
tube 4: 3 g of sugar
tube 5: 4 g of sugar
tube 6: 5 g of sugar
In tube 1 nothing happend, there was no activity of yeast. In other tubes gas was produced by yeast. In tube 3 and 5 was so much gas that baloons dropped off from tubes.

Eduardo, SpainProtocol:Put 200ml of water in each of 3 bottles. Put a spoonful of yeast in each bottle Put 1g of sugar in the second bottle and 5 g of sugar in the third one. Put a ballon on top of each bottle as a lid (different colours)wait 1h to see the final result.Results: the balloon in the bottle without sugar did not experiment any inflation. The balloon in the bottle with 1g of sugar suffered a little inflation. The balloon with 5g of sugar experimented the biggest inflation. Conclusions: The quantity of sugar is plays an important role in the yeast activity.Difficulties: Find test tubes, so I used bottles of water instead. Doubts or questions: How much of each ingredient do I need? How much time do I need to wait?

nozal_eduardo — 2018-03-18 18:45:35 UTC

Zvonko, Serbia

gzvonko62 — 2018-03-18 19:03:55 UTC

Natalia Grushko, Ukraine

grushko_nat — 2018-03-18 20:00:12 UTC

1. Pour 3 tablespoons of warm water into the bottle. Put the bottle in a bowl with warm water.
2. Pour 1 teaspoon of sugar into a bottle of water. Then add half a packet of yeast. Shake the contents of the bottle.

3. Put the ball on the neck of the bottle. After a while he will start to inflate.

Yeasts are living organisms that feed on sugar. Having processed sugar, they secrete bubbles of carbon dioxide, so the ball was inflated. In the heat process is faster.

Bhagyashree. India

bhagyashree_semlani — 2018-03-19 05:40:26 UTC

I conducted this experiment with grade 7 so as to teach them the reaction taking place and formation of gas.
The activity went well. Sugar plays a very important role.
The only difficulty I faced while doing this experiment was the balloons i procured had a big mouth compared to the test tubes I had so I had to conduct the same experiment again with a conical flask. The balloon with maximum sugar inflated the maximum and one with no sugar did not inflate at all.

Klara,Austria

2018-03-19 07:37:44 UTC

2018-03-19 10:37:53 UTC

Rishu,India

2018-03-19 13:34:16 UTC

Test tube with max. sugar concentration Inflates maximum.

Špela, Slovenia

rozman_spela — 2018-03-19 14:04:13 UTC

I have decided to use 5,5 g of yeast in each testing tube. I used water at room temperature and varied the amount of sugar and amount of water and thous created the solutions I have decided on (0%, 12%, 25%, 35% and 56%).

The test tube is labeled 0g - it has no sugar added. The second bottle contains 12 g of sugar and 88 g of water (12% sugar), the third 25 g of sugar and 75 ml (25% sugar) of water and so on. The second bottle has the same percentage of sugar as the "spoiled" jam and the last bottle (56g) represents the "unspoiled jam"

After 15' the second (12g) balloon was inflated, the third (25g) only slightly. After 40' the second (12g) was even more inflated, the third slightly less, the forth (35g) started to inflate. I left the experiment active over night. After 17 hours the second and third were very inflated, the fourth less so. The first (0g) and the last (56g) did not inflate at all.

I had no trouble with the experiment, the instruction you gave was very straight forward.

Lucia Italy

2018-03-19 14:31:23 UTC

Put the following substances in three different tubes (use the same amount of each substance):

test tube n. 1: water + brewer's yeast
test tube n. 2: water + sugar
test tube n. 3: water + brewer's yeast + sugar

Quickly attach a balloon to the mouth of each tube.

Héctor, Spain

2018-03-19 17:30:52 UTC

Test results:
The more sugar concentration , the more yeast activity, so the more gas produced.

Pinelopi, Greece

2018-03-19 17:56:23 UTC

I used 5 tubes. Each tube had the same amount of water (100ml) and yeast (20gr). The amount of sugar was different. In the 1st tube: 5gr, 2nd: 10gr, 3rd: 20gr, 4th: 30gr and 5th:50 gr. i found out that the baloon inflation depends on the amount of sugar in the tube, and the more sugar the tube contains maximizes the inflation.

Michelle Ireland

2018-03-19 18:57:08 UTC

Protocol: I used 5 grams of dried yeast in 100ml of water in 4 flasks, labelled A to D. Then I added 0grams sugar, 10grams sugar, 20grams sugar and 30 grams sugar to the flasks, and put a ballon over the neck of the flask.
Flask D inflated the most.

Materials: 4 small bottles,8 grams of yeast, 200ml of water, 34 grams of sugar and four ballons.

ingoalster — 2018-03-20 06:22:05 UTC

Experiment:
1.Pour 50 ml of water and 2 grams of yeast in each bottle.
2.
In bottle n.1 add 2 gr. of sugar and seal the bottle with a ballon..
In bottle n.2 add 7 gr. of suggar and seal the bottle with a ballon.
In bottle n.3 add 10 gr. of sugar and seal the bottle with a ballon.
In botlle n.4 add 15 gr. ob sugar and seal the bottle with a ballon.
WAIT...
What happens?
Bottle n.1: nothing
Bottle n.2: the ballon inflates a little.
Bottle n.3: this ballon inflates more than in the bottle n.2
Bottle n.4: the ballon is the most inflated.

The conclusion is that the amount of sugar influences in the production of gases.

Mustafa BOZOĞLAN, Turkey

mdbozoglan — 2018-03-20 08:07:17 UTC

Four test vessels were placed in turn,
1) 5 gr sugar + 100 ml water + 1 equal parts yeast
2) 10 g sugar + 100 mL water + 1 equal part yeast
3) 15 g sugar + 100 mL water + 1 equal part yeast
4) 20 gr sugar + 100 ml water + 1 equal parts yeast
I prepared the solutions. I put 4 plastic rubber balloons into the mouth of the test vessel with the pharmacy tire. I waited for 1 day in a cool and light-free environment. the first hours did not change much but after a while the balloon filled volume increased from 26-28 hours until the amount of the bubbles was less than the amount of sugar.

Dimitris,Greece

2018-03-20 09:26:14 UTC

I had 5 tubes. 200ml water 20 ml yeast. 25gr 75gr 100gr 125gr 175gr of sugar .25 and 175 almost didn't inflated .100gr had inflated the most .

Rosy, It

2018-03-20 09:33:49 UTC

I try this experiment with students of the third class of the Primary school.
They enjoied themselves to see what was happening, but I have some problems to decide the quantity of the ingredients to use for a good result.

Marija

2018-03-20 10:28:50 UTC

My results are completely same as everyone had. :)

Ana Molina/Spain

2018-03-20 12:29:54 UTC

I have had this experiment with my students of the secundary school last year. The results are the same I see here and they really enjoid the experiment. I remember we need some time to wait the yeast grow up, half an hour more or less.

MaríaJosé, Spain

mgarcia58 — 2018-03-20 13:10:21 UTC

The more sugar that the composition has,the more gaz the mix produces.

Marina del Barco SPAIN

marina_bm6 — 2018-03-20 13:19:21 UTC

EXPERIMENT RESULTS
The more sugar a preparation has, the less active yeasts are. You can confirm it by checking the amount of gas produced.

Using 10 grams of dried yeast in 50ml of water in 4 plastic bottles, labelled 1 to 4. take away the cup and place a balloon on top. Adding 0 grams sugar, 10 grams sugar, 20 grams sugar and 30 grams sugar to the bottles. 4th balloon got bigger

2018-03-20 22:09:13 UTC

Alexia, Malta

2018-03-21 08:32:19 UTC

Experimental Procedure:
· 200 ml of water were poured into 5 conical flasks

· A teaspoon of yeast was added to each conical flask

· 4 plastic containers were prepared with different masses of sugar: 1g, 2g, 4g, 6g.

· Each conical flask was labelled with the amount of sugar that would have been added. The last conical flask would not have any sugar added in order to serve as a control. This conical flask was labeled “control”.

· Sugar was poured simultaneously in all conical flasks and immediately covered by the balloon.

· The set up was observed and left for 30 minutes.

Observations:

· The conical flask containing water only (control) and conical flask with 1g of sugar did not produce any changes or inflation to their balloon.

· Conical flasks containing 2g, 4g and 6g of sugar were observed inflating the balloon. The 2g balloon was the least inflated, followed by the 4g and the 6g balloon.

Conclusions:

· As the sugar content increases the amount of gas produced inflating the balloon increased. Therefore, as more sugar is added, yeast reacts more to produce more gas.

YOLANDA M (SPAIN

yolandamarron — 2018-03-21 09:48:02 UTC

Objective: hypothesis to be tested “ the sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time”

Materials:

4 conical flask, water,Yeast, Sugar, balloons

Experiment:

1st In each conical flask labeled from A to D add 200ml of water and 5g of yeast.

2nd Add different amount of sugar in each conical flask; A no sugar, B 5 g of sugar, C 10 g of sugar, D 15 g of sugar.

3rd Seal all the conical flask with a balloon and wait some time to observe if something happened

Results: conical flask A with no sugar nothing happened, B is slightly inflated, a small amount Objective:of gas is produced, C is more inflated than B and finally D is more inflated than C

Conclusion: the more amount of sugar, the higher inflation of the balloon.

Jasenka, Croatia

2018-03-21 10:40:16 UTC

We use this experiment in chemistry to show students how fermentation works. Basically, more sugar you put in a bottle the more activity of the yeast will be observed and the baloon/or plastic bag will be filled with more gas.

Izabela 2, Poland

2018-03-21 12:51:39 UTC

Protocol:
1. Materials: 5 tubes, 5 bags of dried yeast, 5 balloons, mineral water, cup to measure , sugar and teaspoons; 1 teaspoon= 5 g sugar

2. Procedure:

control tube- 50 ml water, 1 bag of dried yeast /7g/, baloon
experimental tubes:
A. 50 ml water, 1 teaspoon of sugar, 1 bag of dried yeast / 7 g yeast/, baloon
B. 50 ml water, 2 teaspoons of sugar, 1 bag of dried yeast, baloon

C. 50 ml water,
3 teaspoons of sugar, 1 bag of dried yeast, baloon
D. 50 ml water, 4 teaspoons of sugar, 1 bag of dried yeast, balloon

Observing during 60 minutes, room temperature;

Results:
Control tube – no gas

A. Small balloon

B. Bigger balloon

C. The biggest balloon

D. Big balloon

Question:
How to choose the amount the ingredients?

Theodor L. Greece

theo_leftheroudis — 2018-03-21 16:46:58 UTC

After 2 failed attempts, my final results and conclusions from the experiment are as follows:

My initial hypothesis (1st case) was confirmed in part. The amount of sugar slowed the fermentation, the more the gas was observed later in the balloon.

Probably the sugary mixture (amount of sugar and water) was not enough to stop the reaction.

Experimental procedure.

Each test tube had a maximum capacity of 20 ml.

To each tube was added 5 ml of water and yeast mixture. (30 ml of warm water with 3 g of yeast).

The sugary mixture was made from 30 ml of water with 15 g of sugar.

· In the tube with the yellow balloon I did not put any sugary water at all.

· In the tube with the light green balloon 3ml of solution.

· In the tube with the dark green balloon 6ml of solution.

· In the tube with the purple balloon, 9ml of solution.

· In the tube with the red balloon 12ml of solution.

What made me difficult in the process?

· Find the right proportions in water and yeast as well as water with sugar.

· Working with my children.

· My wife.

· I did not make a good start, I did not see the fruit-sugar ratio on the jam.

· I did not know where to start.

f I had doubts and questions in the process ... and of course I had.

Is quantity enough?

· Why do not you incorporate sugar or yeast into water?

· How do I put the balloons tightly on the tubes?

· Should I stir them up to shake them? if so how many?

· Anytime should I look at them and take photos?

· Are balloons okay or have any small holes?

· Will I Prepare?

More on my learning diary. https://padlet.com/theo_leftheroudis/Theo_EUN_ACADEMY

Zdena, Czech Republic

2018-03-21 17:37:33 UTC

I was kind of improvising due to lack of test tubes, so I simply used ballooons for reactions. What I used - 4 balloons, a bag of dry yeast, two tea spoons of sugar, few drops of lemon, water (80ml, divided proportionally) . Balloons got numbers:
1. yeast, water
2. yeast, water+sugar
3. yeast, water, sugar+fex drops of lemon (not enough:-()
4. Yeast, water, lemon
I took pictures after an hour and 2.5 hours. The reaction went best with sugar (see a pic below)

Nataša, Slovenia

koprivnikarn — 2018-03-21 20:34:10 UTC

Noel, Malta

noel_harmsworth — 2018-03-21 20:48:27 UTC

Here is summary of how I tested my hypothesis:

10g of baker’s yeast were added to 150ml of water and mixed well. 5ml of this mixture were poured in each of 5 test-tubes. Different amounts of sugar were added to 10ml of water as follows:

Tube 1: 0g sugar
Tube 2: 0.5g sugar

Tube 3: 2.0g sugar

Tube 4: 3.5g sugar

Tube 5: 5.0g sugar

The sugar mixtures were added to the respective yeast-containing test-tubes and a balloon was attached to the rim of each tube. Mixtures were all shaken, labelled and left undisturbed for some time.

Observations: After 3 hours, balloons 2 and 3 had inflated most. Balloon 4 inflated to a slightly smaller size, while balloon 5 had barely just started inflating. Balloon 1, the control test-tube, did not inflate at all. These results are illustrated by the second picture on my padlet.

The results show primarily that:

1. Sugar is needed for yeast to respire and emit a gas (CO₂). In the absence of sugar (tube 1) no gas was produced.

2. Too much sugar, over a certain limit, can inhibit the amount the yeast activity (tube 5).

Anna Italy

2018-03-22 09:39:31 UTC

This is the synthesis of the protocol I used, working in collaboration with my religion colleague:

1.5 g of brewer's yeast were added to 1.8 ml of water without mixing, in each of the 5 tubes. Different amounts of sugar have been added to the mixture:

Test tube 1: sugar 0 g
Test tube 2: 3 g of sugar
Test tube 3: 6 g of sugar
Test tube 4: 9 g sugar
Test tube 5: 12 g sugar
we added a sixth yeast-free test tube with 1.8 ml of water and 15 g of sugar.  A balloon was attached to each tube. The blends were left undisturbed for about an hour.

Remarks: after 1 hour, the balloon 2 had completely inflated. The other balloons were deflated except for Balloon 3 which was slightly swollen.

The results of the experiment mainly show that:

1. Sugar is necessary for the yeast to ferment and release carbon dioxide (CO2). In the absence of sugar (tube 1), no gas was produced as was the absence of yeast in the tube 6.
2. Too much sugar, in tubes 4 and 5 have inhibited the quantity of yeast activity with a low production of carbon dioxide.Conclusions:
The experiment was successful but we found some procedural errors. We would have to mix the mixtures before inserting them into the tubes. In fact, only the tube 2, which was slightly mixed gave good results.

Maria DC

mariadecarlo — 2018-03-22 09:39:42 UTC

This is the summary of the protocol with the science colleague:
1.5 g. of brewer's yeast were added to 1.8 ml of water without mixing, in each of the 5 tubes. Different amounts of sugar were added to the mixture: 1st tube 0g sugar; 2nd tube 3g sugar; 3rd test tube 6g sugar; 4th tube 9g sugar; 5th tube 12 sugar. We added a 6th tube with 1.8 ml of water and 15g of sugar, without yeast.
At each test tube we put a balloon like a hat ... The blends were left undisturbed for about an hour ....
Comments after one hour:
the balloon 2 was fully inflated, the others were deflated with excitement for the balloon 3 which was slightly swollen.
The results of the experiment mainly show that:
the sugar is necessary so that the yeast can ferment and emit carbon dioxide. In the absence of sugar (test tube 1), no gas was produced as in test tube 6 due to the absence of yeast.
Too much sugar (in tubes 4 and 5) have inhibited the activity of yeast with a low production of carbon dioxide.Conclusions:
The experiment was successful and we detected some procedural errors. We would have to peel the ingredients before inserting them into the tubes. In fact only the test tube n. 2 which was slightly misdirected gave good results.

Gaia, Italy

gaialombardi69 — 2018-03-22 10:54:22 UTC

This is the protocol of the experiment I held in my class as part of a CLIL project about "easy chemistry" (3rd grade)
1) Add 50 g. of yeast to 150 ml of water and stir well
2) put 20 ml of water and yeast in each tube;
3) add sugar to each yeast in this proportion:
tube 1: 0 gr sugar
tube 2: 1 gr sugar
tube 3: 2 gr sugar
tube 4: 4 gr sugar
tube 5: 8 gr sugar
Cover each tube with a balloon.
Label the tubes indicating the amount of sugar you put in it.
Observation: after one hour, the first balloon didn't inflate. The other 4 balloons inflated in different ways.
The fifth balloon fully inflated.

Conclusions: in absence of sugar, the yeast doesn't develop gas.

The quantity of sugar affects the inflation of the balloons.

monica garcia , spain

2018-03-22 21:25:37 UTC

The experiment was made with same amount of yeast : 2 g of sugar, 5g , and 10 g . It is clear that a little amount of sugar helps yeast to grow and two much sugar really inhibits

yeast and nothing, you do not "feed" the yeast, with sugar the yeast is "happy" to be fed. If you have to much sugar something inhibit the gas building by accident we had this with beer last week ago

a_scheuringer — 2018-03-22 22:28:48 UTC

Kristina, Slovenija

2018-03-23 22:05:53 UTC

My hypothesis was that the fruit preparation with added sugar left the jar B unspoiled. I have decided to tray with different amounts of sugar. I have used 4 test tubes, 4 balloons, digital thermometer, test tube rack, yeast, mineral water and sugar.
Test tube 1: 2g of yeast, 3 ml of mineral water, 1g of sugar, orange balloon;
test tube 2: 2g of yeast, 3 ml of mineral water, 2g of sugar, yellow balloon;
test tube 3: 2g of yeast, 3 ml of mineral water, 3g of sugar, green balloon;
test tube 4: 2g of yeast, 3 ml of mineral water, 4g of sugar, blue balloon.
Observations: after two hours only one balloon inflated, the orange one. After next two hours the orange balloon inflated a little bit more, the yellow balloon was partially inflated, the green and the blue balloons inflated very slightly, almost insignificantly.
Conclusion: the sugar content affects on yeast cells. More sugar causes more gas production. (Very) High amounts of sugar some how inhibit gas production. Questions: How much of yeast do I have to use for appropriate results? Why do I have to use mineral water? What is the difference between mineral water and potable water for yeast cells?

Paulo Dionisio, Portugal

paulo_dionisio — 2018-03-24 12:06:48 UTC

In the classes of biology or chemistry we use experimental classes to explain how the process of anaerobic fermentation of transformation of a substance into another from microorganisms, such as bacteria and fungi, called in these cases of ferments. Thus, the more sugar is put into a container (test tube), the more yeast activity will be observed and consequently the more gas will be produced at a certain time. Yeast gas formation depends on the sugar concentration.

Michela, Italy

michelapellizzari4 — 2018-03-24 14:00:13 UTC

PROTOCOL:

AIM: “The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time”

MATERIALS:

- YEAST

- MINERAL WATER

- SUCRE CHANNE WITH SACCAROSE

- 4 IDENTICAL GLASS

- 4 BALLONS

PROCEDURE

In each glass add 2cl of water and 3g of yeast, gr of sucrose as indicated into protocol and then close the glass with a balloon.

- 1 glass contains 2cl water + 3g of yeast + 0 g sucrose;

- 2 glass contains 2cl water + 3g of yeast + 5 g sucrose;

- 3 glass contains 2cl water + 3g of yeast + 10g sucrose;

- 4 glass contains 2cl water + 3g of yeast + 15g sucrose;

OBSERVATION

After one hour, the first balloon didn't inflate. The other 3 balloons inflated in different ways.

CONCLUSIONS:

In absence of sugar, the yeast doesn't develop gas.

The gr of sugar content affects the level of activity of yeast cells. More sugar causes more gas production.

But I have not found how much gr of sugar inhibit gas production, and I have not found how much ml of gas were produced.

Questions:

How much of yeast and sugar do I have to use for appropriate results? What appends if I use warm water? How many glass do I have to use to find the exactly gr of sucrose for the gr of yeast? Can I use a syringe to test the ml of gas produced?

Difficulties:

Stop my daughter who wants try and try again and find all materials to try and try again.

We had fun with balloons.

Arnaud, France

2018-03-24 14:03:09 UTC

My experience was a failure. Indeed, this may have been due to inappropriate material. The balloons used were birthday balloons, too thick it seems. They did not inflate as expected.

Lina from Lithuania

step_lina — 2018-03-24 15:22:01 UTC

1g/2g/4g/8g/1

Testing hypothesis:
The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time.

Execution
1. Split the yeat in five equal pieces (3g)

2. Weigh five unequal amounts of sugar – 1g/2g/4g/8g/16g.

3. Mix every amount of sugar with the same amount of mineral water (4ml) and yeat.
4. Put every amount of the mixture in a single jar.

5. Put a ballon over it and control every half hour the increasing of the volume.
Difficulties while experimenting:
1. The time needed to put the balloons on the test tubes.

2. We cannot measure the difference in the rate of gas production between tubes 4 and 5.

step_lina — 2018-03-24 15:28:22 UTC

Testing hypothesis: The sugar content in a medium affects the level of activity of yeast cells, and thus the quantity of gas they produce in a given time. Execution 1. Split the yeat in five equal pieces (3g) 2. Weigh five unequal amounts of sugar –

Reneta Raicheva, Bulgaria

2018-03-24 18:40:42 UTC

Here's our experience of holograms. It was interesting for my young learners. Enjoy! Thxxx! :)
https://www.thinglink.com/scene/916114570911678467

Aiki

2018-03-24 19:36:50 UTC

I don't have materials at home and it's weekend. But I have done this experiment at school with students so I know the results.

Grażyna, Poland

sp171wesola — 2018-03-25 20:51:33 UTC

I had to use my own sugar solution with glucose

I didn’t have balloons, so I used gloves and cut off the fingers

The fingers were not identical, it was also impossible to place them on my measuring cups in the same way

I “dissolved” the dry yeast i some water to make it easier to measure the same amount of yeast

I put the same amount of yeast solution into each cup - I used a syringe

I put subsequently 10 - 15 - 20 - 25 - 30 milliliters of glucose solution to the cups

Problems:

I added sugar to yeast not at the same time
I covered the cups not at the same time
My balloons were too tight
The space left in the cup was not the same, so there was less space for gas
and I do not know how much air was in each ballon when I placed them
FAILURE!!!!!!

BUT after some time the gas was produced!!!
https://drive.google.com/open?id=1xFr4Ab8tF2OD_rTla43JS6ztJXdK_8Ra

sunce

suncezgb8 — 2018-03-26 14:08:03 UTC

Fiona

2018-03-26 15:01:35 UTC

Put the same amount of yeast and water in each container. Using a mass balance place varying amounts of sugar into each container with the water and yeast. The container with the least amount of sugar will produce the most gas as sugar will prevent yeast from flourishing. The one with the greatest amount of sugar will produce the least gas as sugar will inhibit yeast growth..
Note that the temperature should remain constant at all times so there is only one variable.

Carlo Italy

carlogino — 2018-03-26 18:52:08 UTC

The experiment was made with the same amount of yeast The ingredients used for the experiment are: 2 g of sugar, 5 g and 10 g The amount of yeast is constant and this has allowed joined with a little sugar to grow abundantly.

Jason, Ireland

JasonComerford — 2018-03-26 19:39:05 UTC

Cecília Pereira, Portugal

ceciliadpaiva — 2018-03-26 20:03:57 UTC

chemingui firas

cheminguifiras1966 — 2018-03-27 10:47:28 UTC

nabeul , Tunisia
I summirize my testing in the following padlet

Joyce India

sec_coordinator — 2018-03-27 13:27:54 UTC

Joyce India

2018-03-27 17:32:14 UTC

Initially there was not much activity , the temperature of the water was increased to 38deg and then the balloon started to inflate indicating the activity in the yeast. The sugar concentrations were different in each tube.

Eugenia, Romania

2018-03-27 19:57:49 UTC

Dorota, Poland

2018-03-27 20:05:56 UTC

Experiment: yeast fermentation dependence on sucrose content

Protocol:

· Base sucrose solution (A): 22g sucrose + 18g H₂O

· Flask (1): 20ml H₂O

· Flask (2): 5ml (A) + 15ml H₂O

· Flask (3): 20ml (A)

· 2 drops of yeast suspension in water were added to every flask and they were closed with deflated balloons.

Observations:

After 20 hours at room temperature, the balloon on flask (2) was inflated, while the other did not change volume.

Conclusion:

Yeast do not ferment glucose glucose to CO₂ in water and in high concentration of sugar, but they do if sucrose content is about 14%.

2018-03-27 20:13:26 UTC

Kavita, India

2018-03-28 03:19:50 UTC

I experimented using dry yeast as we don't have the product mentioned in the video easily available in India. Since I was experimenting at home, I used teaspoons to measure sugar, 1/4, 1/2, 3/4/ and 1 teaspoon of sugar and added same quantity of yeast and water. After some time approx 15 minutes, the tube with one teaspoon of sugar showed more reaction and the balloon started filling with gas. The one with the least sugar showed very less gas release.

Kristina, Croatia

klucic5 — 2018-03-28 09:40:01 UTC

I usually use yeast when I prepare bagle for my kids and then I put warm milk and sugar to activate yeast.

Testing the hypothesis

2018-03-30 10:39:21 UTC

Hypothesis: The sugar content in a medium affects the level of activity of years cells, and thus the quantity of gas they produce in a given time

Equipment: 5 test tubes, 5 balloons, yeast, water, sucrose

Method:
Measure out 5 equal amounts of yeast (5g) as well as 5 equal volumes of water (50ml)

Measure out 5 unequal volumes of sucrose solution (0mL, 5mL, 10mL, 15mL, 20mL)

Label test tubes A,B,C,D,E

Into each test tube place the water, then the yeast, then the sucrose source, placing the balloon on top of the test tube each time

Note and record the result

Results:
The test tubes with low sucrose solution produced more gas

Errors/Problems encountered
Time
Each test tube was started at separate times

Orsola ,Italy

orsola_parisi58 — 2018-03-30 11:24:00 UTC

As we have seen, the experiment was conducted with the same amount of yeast in the different tubes while the added sugar varied. We could see that as the sugar concentrations grew, the balloons were becoming more and more swollen. This is due to the fact that as the concentration of sugar increases, the concentration of the gas that develops from the reaction also increases.

Miguel Angel, Burgos (Spain)

kapy83 — 2018-03-30 11:51:51 UTC

The experiment does not allow to verify the hypothesis.
First: the yeast that is usually used is chemical yeast or rather "chemical booster", composed of phosphates and carbonates. It is not organic yeast, so the bubbling observed is decomposition in CO2.
It has been a very fun experience that I did with my daughter anyway.
The differences observed in the photograph are due to:
1st my daughter mistakenly removed a balloon.
2nd in the sample with the most amount of sugar, it is possible that the viscosity of the liquid makes CO2 bubbling difficult (or maybe, the balloon was punctured).
I'll repeat the experiment when I get real yeast.

Anna, Italy

prof_deruvo — 2018-03-31 13:02:44 UTC

Hypothesis: The sugar content affects the level of yeast activities.
Materials: 5 bottles, 5 balloons, 5 samples of dry yeast (7 gr), gucose syrup for cakes , water.
Procedure:
I didn’t have a balance to misure the syrup so I used a graduated container for preparing cakes. The syrup was thick and sticky so it wasn’t easy to measure the ml precisely. I filled up each bottle with growing quantity of syrup and put them at level with water up to 100 ml. At the end I added a small bag of dry yeast (7 gr) and shook. I closed all the bottles with a balloon. I made three photos, just prepared , after half an hour, after one hour. In this post you can the photo made after one hour. From left the bottles contain:
1° just water and yeast
2°water, yeast and 25 ml of glucose syrup
3°water, yeast and 50 ml of glucose syrup
4° water, yeast and 75 ml of glucose syrup
5° yeast and 100 ml of glucose syrup.
After one hour in the 1° case the balloon blow up a little, the 2° was the quicker and the most to inflate, the 3° blow up to but less and slower, 4° and 5° bottles don’t
blow up at all.
Glucose help yeast activity but not if too concentrate because of lack of water I think.

Cristina Raposo, Portugal

ciraposo — 2018-04-02 16:00:46 UTC

The problems I encountered were: 1 - the time of start for each container was different as (even with help) it was very difficult to measure sugar and put balloon on top to start at the same time; 2 - the water temperature for each container might not have been exactly at the same temperature at the starting time.

Anamaria, Romania

2018-04-03 06:33:46 UTC

The sugar affect the medium activity.

Slavica, Croatia

ps_slavica — 2018-04-03 18:03:26 UTC

experiment successful!
same temperature, different mass of sugar and the results are not the same.

Bertha, México

chem_ur_v17 — 2018-04-03 19:19:15 UTC

Bertha, México

chem_ur_v17 — 2018-04-03 19:26:03 UTC

I don't know if the concentrations are right. but the experiment is great!!

Kathryn, Armenia

quickstepintomyheart — 2018-04-04 06:29:28 UTC

Hi all, I really appreciate your posts. Based on where I am located, it has been a bit hard to find all of the materials. For example, I had to try 5 shops to finally get balloons (there are only 5 shops in town that cary such things). Has anyone used a substitute successfully? If so what did you use?
Thanks
Kathryn

Semih, TÜRKİYE

2018-04-04 19:55:39 UTC

Semih, Turkey

2018-04-04 20:14:56 UTC

In this experiment, the amount of sugar in a medium level produces more gas so that we testify there is a prominent growth of yeast cells. But somehow as we increase the amount of sugar excessively, it inhibits the growth of yeast cells and that prevents the gas production.

Salima, India

2018-04-06 03:22:24 UTC

I did the experiment with slight variation. I had taken three test tubes
A with no sugar
B with moderate sugar (50%)
C with very high and very little water
The balloon increased in size only for the B, the one with moderate sugar
There was no such doubt while performing the experiment. In fact the results were very appealing. As seen in the picture, the middle one has maximum inflation of balloon as there was 50% sugar

Ricardo RG

RicardoRG — 2018-04-06 19:00:05 UTC

Majid - Pakistan

2018-04-09 15:54:23 UTC

Sugar content added in moderate quantities to the mixture of water and yeast will produce the most amount of gas, which can be seen by the size of the inflated balloon.

Serena - Italy

serena_dorigotti — 2018-04-13 10:10:58 UTC

Experiment result with immobilised yeast
First step: immobilization of yeast in sodium alginate gel. It allows to work in more controlled conditions.
Second step: measurement of CO_² production with pH indicator.

Sarah, USA

sab205 — 2018-04-14 16:59:34 UTC

Ourania Lampou, Greece

2018-04-15 09:24:23 UTC

I tried the experiment twice. The second attempt was successful.

Audrey Dublin

a_carty1 — 2018-04-15 12:26:15 UTC

I have done a similar experiment before but never using sugar. I am at home but will set this up with TY

Ozrenka, Croatia

2018-04-15 13:22:49 UTC

I use this type of experiment in my classes. And my students do it easily. Results are great.

zeynep,Turkey

2018-04-16 13:20:24 UTC

I did the experiment my third attempt was succesful

Jeane de Fatima, Rio de Janeiro - Brasil

jeanedefatima — 2018-04-17 13:16:09 UTC

The reaction with water in the mass it does not efferve so much and does not produce as much gas, when the alcohol is used the chemical reaction will produce more gases

Samet Yavuz TERZİ , TURKEY

2018-04-19 07:48:14 UTC

Selda

seldasezer1983 — 2018-04-20 18:23:16 UTC

With has lots of gas

CİHAN SÜLE

cihansulebilsem — 2018-04-22 02:40:15 UTC

Cihan Sül

cihansulebilsem — 2018-04-22 02:41:31 UTC

The result successful

Nurhayat Kayar

2018-04-23 16:13:01 UTC

1.I didn't any difficulty came across while experimenting.
2.Idin't have any doubt.
The result is successed.

2018-04-24 08:38:20 UTC

nazım kırdaş
I did not encounter any difficulties while experimenting.
when the end result of the experiment was examined, a close hypothesis was obtained.

meryem eğrioğlu

megri_1971 — 2018-05-07 19:13:03 UTC

turkey
proper heat and time, has lots gas volume

AYS

2018-11-02 21:17:38 UTC

özlem

2018-12-02 13:00:20 UTC

the result of experiment is nearly same

Eylem GÜRKAN

eylemgurkan — 2019-01-27 22:08:47 UTC

It can produce less sugar and medium amount of sugar gas. But enough sugar is preventing gas production.

çağdaş turan turkey

113aytoldu — 2019-03-21 08:12:14 UTC

the result of experiment is nearly same

çağdaş turan

113aytoldu — 2019-03-21 08:12:55 UTC

I don't know if the concentrations are right. but the experiment is great!!

Δημήτρης

dkelefiotis — 2019-06-02 10:39:35 UTC

Παρατήρηση μετά από παραμονή σε θερμό υδατόλουτρο 30 min
------------------------------------------ζάχαρη
(ml) %w/v Παρατήρηση
-------------------------------------------
0 0 % Τζούφιο
1 8% Φούσκωσε χαλαρά
3,5 28% Φούσκωσε καλά
6,5 52% Τζούφιο
9 72 % Τζούφιο
-------------------------------------------
Προβλήματα:
1. Δεν παρατηρήθηκε δημιουργία αερίου σε θερμοκρασία δωματίου. ΛΥΣΗ: Έβαλα τους σωλήνες σε ένα ποτήρι με λίγο ζεστό νερό (υδατόλουτρο)
2. Δυσκολία στη ζύγιση και μετά στον υπολογισμό των συγκεντρώσεων της ζάχαρης. Πιθανά μεγάλα σφάλματα που δεν επηρεάζουν την γενική εικόνα.
Συμπέρασμα
Η μαγιά αναπτύσσεται καλύτερα σε μεσαίες συγκεντρώσεις ζάχαρης και δεν αναπτύσσεται σε έλλειψη ή σε μεγάλες συγκεντρώσεις ζάχαρης
Πρόταση
Να καταναλώνεται γρήγορα το προϊόν με μικρή συγκέντρωση ζαχάρων

Ivica G.

ivica_gregurec — 2019-09-09 20:17:38 UTC

I tried the experiment twice. The second attempt was successful.

fd

kl30385 — 2020-10-22 23:43:54 UTC

7.8 out of 10

2022-02-18 02:25:58 UTC

Too much water

FUNNY SHIT

2022-02-18 02:27:02 UTC

You