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Baker's Yeast & Sugar = Ethano & Carbon Dioxide

jimscott

Tropical Fish Enthusiast
That dry ice topic and Aviator's post that didn't develop got me thinking... and googling:

Supermarket products:
sucrose
fructose
lactose
baker's yeast

Apparatus and glass wares:
hotplate
3 beakers 100 mL
3 snap-cap vials 20 mL
glass stirring rod
watchglass d = 8 cm
thermometer


Experimental procedure:

40 mL of water are placed in each of three 100 mL beakers. 10 g of sugar are dissolved - in beaker 1 lactose, in beaker 2 fructose and in beaker 3 sucrose. 1 g of baker' yeast is adedd to each of the sugar solutions. The solutions are warmed to 25 to 40 °C.


Results:

An unequal strong foaming can be observed in the three beakers. The strongest foaming occurs in the beaker containing glucose. A moderate foaming takes place in the beaker with fructose. Evidently lactose does not react with yeast.

Backhefe1.gif


Backhefe2.gif


http://video.uni-regensburg.de:8080/ramgen/Fakultaeten/Chemie/Org_Chemie/Demonstrationsexperimente/Backhefe.rm


Discussion and background:

Baker's yeast enzymes convert sugar (glucose, fructose) to ethanol and carbon dioxide. The fermentation process is accompanied by the release of carbon dioxide which causes foaming.

Baker's yeast is cultivated from the strain Saccharomyces cerevisiae because of its superior fermentation abilities. The yeast propagates in pure culture using special culture media comprised of melasse and other ingredients. With respect to their metabolism baker' yeasts are facultative anaerobe. They can ferment or respire depending upon environmental conditions. In the presence of oxygen respiration takes place, without oxygen present, fermentation occurs.

Baker's yeast plays a key role in bread dough fermentation. Amylases present in flour, break down starch into a smaller sugar, maltose. The reaction starts as soon as water is added to the flour and stops during baking. The action of the flour amylases is completed by an enzyme of yeast, the maltase, which splits maltose into two glucose molecules. Glucose is fermented by the yeast to ethanol and carbon dioxide.

ferment-e.gif


Whaddya think?
 
I think if you've got no access to dry ice then this is the best way to go. It's not the most pleasant smell or cleanest way though. I'd be curious to see the amounts of CO2 released form each method; my bet says dry ice releases more over a short period while the yeast releases a small quantity over a long period.
 
When I had planted aquariums I played with the ratios till I got a pretty constant output. It would last a couple weeks too!

Too much yeast gave a larger output but one that was short lived.

I used a welch's grape juice bottle that I siliconed an aquarium hose to the lid... IIRC for that size bottle it was a tbl of yeast to a cup or two of sugar... cant remember about the sugar exactly.

But for my purposes, this allowed me to maintain the proper CO2 level and proper pH. The resultant carbonic acid maintained my pH at 6.8 IIRC (none of the nasty side effect of adding phosphoric acid, just as nature intended)

It worked outstanding for my purposes, It was a beautiful set up that was a self supporting ecosystem, It maintianed a nice daphina population so I didnt even have to feed the fish. All I did was give it light and CO2, it had no filtration at all.

all of this is sorta foggy.... we are talking 20 yrs ago

IIRC baking soda and vinegar is another method if you need some in a hurry

oh and when you go to empty the used up mash, omg.... ewwww
 
Dry Ice makes me uncomfortable because of the cold temps that it could produce. I just wanna produce CO2 to asphyxiate aphids!
 
I"m just curious if you could get enough CO2 production to attain lethal levels for the aphids using the bakers yeast method. It may require more than just a few bottles.
I'm going to see if my local Meijer has some dry ice. I'll let you know about the temperature and dry ice when I find out JimScott
 
Dry Ice makes me uncomfortable because of the cold temps that it could produce. I just wanna produce CO2 to asphyxiate aphids!
If you use hot water on the dry ice, there will be less than a 5*F temp drop in the tank (and 'pour' the mist in from the top as I did).

With the yeast method, I doubt that you could ever get CO2 levels that would kill the aphids.

As for the the vinegar / baking soda routine - the foam up that you get upon mixing can be difficult to control and the resulting mix is toxic to plants. Yes - even knowing the risks and knowing about the "foam up", I tried this approach when I was having difficulty locating some dry ice. As expected, one of the mixes was more violent than expected and foamed over some of the pots. Even after rinsing for a long period, I still lost one of the pots(U. blanchetii iirc). That's when I drove the 40 min (1 way) to the ice cream place and got the dry ice....

If you're still scared of low temps, try Av's method. Low risk - eh?
 
interesting, I've never heard of this method for killing aphids, does it work for other pests?

if this worked well i'd love to try it
 
in the aquarium world, the DIY yeast reactors are the best for tanks 10 gallons and under.
the recipe as follows:
2 CO2 reactors (gatorade bottles- i use 24-34 oz bottles)
4 cups of sugar
2 tsp of yeast.

the reason why this works the best is because of the pressurization of CO2 gas that the yeast creates. i dont know what the steady rate given off by dry ice is but im pretty sure it will be #1 inconsistant, and #2 will disperse rather quickly. with yeast, the reaction takes weeks to complete, and a good amount of CO2 will be released at a steady pressurized state.


--OR---
you can get an aluminum tank cylinder, fill it up with CO2, hook it up to a regulator, connect a CO2 approved tubing, place that into your tank, and voila, 5-20 lbs of CO2 gas that could be dispensed in a controlled fashion. this method is rather expensive though. a typical tank costs around $65 bucks, and a regulator is an additional $100. i have both, however, i dont know of any nearby places which i can fill the tank up with CO2--plus, i kinda lost interest in using it :p.


just a reminder, although you probably already know this: allow your tank to breathe at night. otherwise aphids might not be the only thing you'll be killing in your tank.
 
  • #11
I used sugar and yeast for my planted aquariums as well it works fantastic for that. Never had to worry about a regulator sticking and overdosing the fish as happened to several on the planted aquarium forum.

I wonder if you made several CO2 reactors and aimed them into an enclosed space if you could get more a higher ppm in the environment to kill the pests.

Neat dry ice directory, sure aren't many sources around here! LOL
 
  • #12
What's this about a dry ice thread? I was thinking about this before (not for aphids; to kill mice and fleas nesting in my couch x.X ) but don't remember if I made a thread or just bugged Av about it. I think the conclusion I came to was that liquid CO2 was the cheapest by volume, but I'm curious to hear what other people have found.
~Joe
 
  • #13
What's this about a dry ice thread?
Here's the thread. (Didn't think it was hidden....) ???

interesting, I've never heard of this method for killing aphids, does it work for other pests?
In the original post on the frog forum, there was an issue with mites surviving the treatment (also in a follow-up post in the thread by another). I'm very curious to see how well it handles other pests....
 
  • #15
When I had planted aquariums I played with the ratios till I got a pretty constant output. It would last a couple weeks too!

Too much yeast gave a larger output but one that was short lived.

I used a welch's grape juice bottle that I siliconed an aquarium hose to the lid... IIRC for that size bottle it was a tbl of yeast to a cup or two of sugar... cant remember about the sugar exactly.
Mixing the sugar into Jell-O, letting it set in the bottle and then adding a solution of warm water, yeast and a little sugar on the top will result in slow and sustained reaction as not all the sugar is available to the yeast initially. The Jell-O will slowly diissolve, freeing up the sugar to feed the yeast.
 
  • #16
Mixing the sugar into Jell-O, letting it set in the bottle and then adding a solution of warm water, yeast and a little sugar on the top will result in slow and sustained reaction as not all the sugar is available to the yeast initially. The Jell-O will slowly diissolve, freeing up the sugar to feed the yeast.

very nice tek!!

thanks Mobile

anyone for jello shooters :0o:
 
  • #17
I've already been to this site. They only listed places like Praxair and Linde, who supply the big cylinders.

---------- Post added at 09:31 AM ---------- Previous post was at 09:29 AM ----------

Jim, have a squizz at this:
http://www.motosport.com/dirtbike/pr...talogId=103039

for our purpose, this would be the route I would go
Av

That's quite plausible!

---------- Post added at 09:32 AM ---------- Previous post was at 09:31 AM ----------

There's this too! Still on the expensive side but lasts 60-90 days depending on use.

http://homeharvest.com/carbondioxideenrichco2boost.htm
__________________

Cost prohibitive
 
  • #18
You could always put them in a metal rash can with lid and put a lit candle or alcohol lamp. Put the cover on, the flame will consume the oxygen and so on. No light to process the CO2. Place the flame source higher than the plants.
 
  • #19
You could always put them in a metal rash can with lid and put a lit candle or alcohol lamp. Put the cover on, the flame will consume the oxygen and so on. No light to process the CO2. Place the flame source higher than the plants.

I really liked this idea as well and googled it a bit a while back. I ended up finding a couple sources though (dont know how reliable ) that claimed that the oxygen would be consumed until it could no longer sustain a flame but that the residual oxygen levels would be sufficient enough to sustain small critters. i.e. springtails etc... I'll see if I can find the source, it's been a while.

Maybe using the candle + yeast jar would work pretty well?
 
  • #20
Jim, have a squizz at this:
http://www.motosport.com/dirtbike/product/HP-TOOLS-CO2-TIRE-INFLATOR-KIT/?catalogId=103039

for our purpose, this would be the route I would go ;)
Av

This does look like it would work.

On the CO2 boost system, it doesn't produce CO2 fast enough to kill bugs. I have two of the systems.

Using flame or car exhaust; are we confussing carbon dioxide (CO2) with carbin monoxide (CO)? Would they work the same for killing bugs; but OK for the plants?
 
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