The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

H2O2

nicodvb's picture
nicodvb

H2O2

Hi,

yesterday I decided to test a new ingredient: oxygenated water (3% concentration).

I stirred 8 gr of H2O2 with 32 of tap water, 10 gr of rye starter and 30 gr of flour. As you can see the hydratation is high: 133%.

I observed that

-just after 30 minutes the preferment seemed to have grown a bit, quite unusual in my experience

-after 4 hours it had tripled in volume and especially after 24 hours it's still there! It hasn't fallen back a bit. It never happened to me with an almost all wheat preferment.

-no taste and no odor whatsoever

If I had  to judge based on what I've seen I'd say that in normal preferments what is missing (that causes the collapse) is not food, but oxygen. Also, the lack of flavors makes me think I killed the LB and that only yeasts survived, but even alcohol seems to be missing!

What do you think? What about safety, could this small amount of H2O2 be harmful in a 1kg loaf or cause problems when  baking?

Grenage's picture
Grenage

Hydrogen Peroxide will probably kill a host of bacteria, and to be honest I'd be extremely skeptical about ever using the stuff in food.  I'm not sure how it would react with various salts, or the resultant chemicals - I am not a chemist.

Mini Oven's picture
Mini Oven

which breaks down gluten proteins, you have gluten stretching but no bacterial or yeast growth evident with CO2 gas and alcohol/aromas.  The gas inflating the wet dough could just be yeast,  separating hydrogen peroxide into water and oxygen.  Keep an eye on it.  Might be interesting to know what happens when the extra oxygen runs out...

http://www.instructables.com/id/Experimenting-with-Yeast-and-Hydrogen-peroxide./

Doc.Dough's picture
Doc.Dough

Commercial 3% peroxide is both an adequate disinfectant and a good bleach, but has no uses in the kitchen that I know of beyond those applications.  You have no doubt reduced the populations of both LAB and yeast substantially, but I doubt you have killed them off completely. I have used peroxide at 3% in an attempt to surface sterilize urad dal and determine if the leuconostoc bacteria that are the active species in idli reside on the surface or also exist in the bulk of the dal.  Even after 3 hours of soaking in a 3% solution, there is still enough of a residual population (either residual surface bacteria or bacteria that are protected from the H2O2 activity by the bulk of the dal) to eventually inflate the idli batter, though it does take substantially longer.  So I suspect that if you wait long enough the starter will recover from the insult.

fmlyhntr's picture
fmlyhntr

H2O2 is also used to induce vomiting--though I'm pretty sure heating it does break it back down to water and O2 gas. I'd be a little nervous about eating anything made with H2O2 for that reason.

Wild-Yeast's picture
Wild-Yeast

Any LAB in the mixture were eliminated by the hydrogen peroxide. It's not only a good bactericide it's also a pretty good viricide as well. It does have other uses though. Spraying it on the exterior surfaces of poultry and fish drastically reduces salmonella bacteria contamination prior to further preparation. Its use is becoming common in modernist cuisine for this purpose.

Wild-Yeast  

nicodvb's picture
nicodvb

Maybe I killed most of the critters inside and the few remained had more food at disposal? This  would explain the very long duration of the fermentation.

Only after 36 hours the fermets collapsed and exhibited  some flavor.

Mini Oven's picture
Mini Oven

of deteriorating the dough.  Did you bake it?  or fry it?  was it pale?

nicodvb's picture
nicodvb

Mini, I baked my usual 100% rye bread, but I didn't see the slightest difference respect to the usual.

FoodFascist's picture
FoodFascist

To understand the process you need to look at the chemistry here. The reason why hydrogen peroxide is such a good desinfectant and oxydiser is because it's highly unstable (it's pretty hard to keep that weak magnetic bond that holds the extra oxygen atom in place) and on contact with any organic substance (as well as a host of inorganic ones) what happens is that extra oxygen atom is released and its THAT that reacts with whatever it touches. The rest is water. Now what you forget is, the oxygen released from the H2O2 molecule is in a free atomic form, NOT the reasonably stable 2-atom molecule form (which is the oxygen gas). Now, oxygen atoms don't like being in the free form, they aren't chemically or physically stable that way, so they'll look for something to attach to (and steal the lacking electrons from - that's what forms a chemical bond). And chances are, most of the oxygen atoms released will react with something other than themselves, i.e. they won't just form oxygen molecules which will later feed your yeast. They'll react with the organic molecules in your flour, lactobacilli and yeast, forming new organic molecules (but probably not the sort you'll be needing for bread baking).

Unfortunately my knowledge of organic chemistry sucks, I was only ever interested in inorganic, so I can't tell you exactly what sort of gas inflates your starter, but I'd guess that's CO2 which must have formed as a by-product of the reaction of oxygen atoms with organic molecules in your starter. Problem is, although you do have that CO2, you've killed much of your yeast and lactobacilli at the same time.

Don't do this again please :) If you want to enrich your starter with oxygen using hydrogen peroxide, I'd suggest you mix a veeeeeery small amount of H2O2 with water in a lidded glass jar, then screw the lid on tightly and shake it about for as long as you can.  Make sure to only fill the jar to 1/5 or about so the oxygen released will have room to fill. That way, oxygen atoms will have nothing to bond with but other oxygen atoms so you'll hopefully get water and oxygen gas. Use it straight away after opening so the oxygen doesn't escape. I can't guarantee you won't have some H2O2 left in the jar to mess with your yeast though...

nicodvb's picture
nicodvb

Hi Faith, I was searching exactly a method to enrich of O2 the preferment, but evidently I must have enriched it only with oxidizing O rathen than beneficial O2. Very clear explanation, thanks!

FoodFascist's picture
FoodFascist

No prob, Nico. On second thought, maybe some of the gas you observed in your preferment WAS oxygen. I.e. some elemental O went to destroy your little critters, and some bumped into itself to make O2. Doesn't really matter though, because you certainly don't want to kill the starter in your preferment!

I just had a mad idea, not sure how this would work in terms of gluten development, but how about whipping some air into your preferment? I don't suggest you whip all of it (I doubt many mixers would sustain that, and also I'd guess the gluten would be overworked and become unusable). But maybe mixing some plain (i.e. low gluten) flour and water, whipping that and adding that to your preferment would do the trick? Or if you're making a milk loaf, some air can certainly be incorporated into milk by whisking. Or whipped egg is an obvious one, for enriched doughs. Even in plain-ish bread, one whipped egg white in a whole loaf or a two/three-loaf batch won't make much difference in terms of taste but may just add enough air to the dough to make your yeast and LB happier.

FoodFascist's picture
FoodFascist

Nico! All that talk of oxygen reminded me, a pregnant friend from Russia mentined she bought a can of oxygen over the counter (she suffers from episodes of breathlessness while pregnant) and I thought, if you can buy oxygen for personal use in Russia maybe  it's available elsewhere. Sure enough, this UK crowd sell it for only £15 per 8 liters! May even be too much for your baking needs (but then again you could breathe it, too :-)) Of course you'd have to devise some implement to channel the oxygen from the can into your preferment. One would hope a plain metal or plastic tube will do the job. So, if plain air won't do, you could yet pioneer Nico's Amazing Oxygen Loaf! ;-) Yippee!!

nicodvb's picture
nicodvb

Faith, I guess that the only sensible test is to prepare 2 poolishes, one whisking air inside and one without it. Let's see how they behave.