Dark Film on Biga?? | The Fresh Loaf

Dark Film on my Biga??: So I took my Biga out of the fridge after an overnight stay and this is what greeted me. A very thin, but very dark film on top. The light area is where I scraped some of it off to show the difference between normal coloration and the dark film.Has anyo

So I took my Biga out of the fridge after an overnight stay and this is what greeted me. A very thin, but very dark film on top. The light area is where I scraped some of it off to show the difference between normal coloration and the dark film.

Has anyone seen something like this before? I'm assuming some sort of sterilization procedure is in order.

Biga recipe (Reinhart whole-wheat challah biga):

227g flour

1g yeast

113g H2O

1 egg

4 egg yolks

I've never made a biga with eggs in it before, and have never heard of it. I have , however, made other doughs with egg(i.e. pasta) and it turns dark after a day or so. It's usually no good at this point. I'd assume that the dark color is from oxidized egg yolk. I really don't know why you'd put egg in a biga. It's usually used as a pre-ferment for flavor and to strengthen gluten in very slack doughs. Egg can't help the gluten and I don't think fermented egg would be a flavor you'd want.

by covering, placing a plastic or oil film directly on the mixture before going into the fridge. Looks like oxidation to me too. I would disagree about egg not helping the gluten in some cases. I normally add egg the following day or the day of baking. I couldn't tell you if it is usable or not. Taste it (and spit it out) and decide for yourself.

I've never baked this recipe but you have. Think it has to do with the red whole wheat? Did the fridge warm up or get packed with lots of food to chill while it was in there?

Mini O

I agree, it's almost certainly oxidation, coupled with the top layer just drying out.

Was your bowl covered at all? I don't think you need to cover the glop directly, but the top of the bowl does need to be covered.

Also, I don't know why he'd put eggs in. I don't think they'd add to the flavor of the pre-ferment through its fermentation, though I haven't tried. Still, a biga is about 55% water, 100% flour and a small amount of yeast. It's a good thing to develop new things, but not such a good thing when you redefine existing terms to cover the new thing. Reinhart's baking is far better than his scholarship.

Mike

Yeah, I'm covering the bowl... the bowl has it's own snap-on cover that I sometimes use, and I use plastic wrap if I don't. As ya'll mention, I think this will probably be solved by either plastic wrap directly on the glop, or add the eggs day of baking. To be honest, I'd rather add the eggs day of... makes the first day much simpler. Especially if I've forgotten to buy eggs :)

I don't think it has anything to do with the red wheat, I've done this recipe from 100% red to 100% white and many combinations inbetween. This is the first time it oxidized like this.

Thanks everyone for the info.