So I did a 2 hour pre-ferment earlier today and I’ve got an overnight one going right now but here’s my question:
What is the yeast fermenting? Standard pre-ferment recipes call for flour, water, and yeast. Does bread yeast have the ability to convert flour starch?
The bread from the earlier batch turned out great. Served it with some red wine Italian sausage soup.
The flour you buy in the supermarket, whether it’s ‘all purpose’ or ‘bread’ flour, has some malted barley flour blended into it.
That’s what the yeasties feast upon.
Well, that makes a bit of sense I guess, but it’s still starch right? I can’t imagine that the 110F water I’m adding is allowing for enzymatic conversion of that malt flour to sugars.
Flour is technically a sugar per se. Yeast can consume a carbohydrate chain of four sugars or less. You’re not trying to ferment the entire loaf, but there’s enough residual sugars in the flour for the yeast to feed on.
Dumb question time - What’s a pre-ferment?
Unless you are keeping your dough at a high temperature, the enzymes will survive & continue to break down the complex carbohydrates into simpler ones, which leads eventually to sugars. The Professor is correct about the added malt in flour, but you can take wheat berries & grind them into flour, and it will still benefit from a preferment.
Not a dumb question at all. A preferment is taking some of the flour from a batch of dough, usually a lot of the water, and just a little of the yeast or sourdough culture and letting it start fermenting well before the rest of the ingredients are added to finish fermenting the dough. This breaks down some of the complex carbohydrates into simpler ones, including sugars, that make for better flavor. Just adding sugar to the dough without prefermentation will not give you the same results.
Sure it can be . . . the amylase in your saliva works at 98.6F . . . just because it’s not the optimal temperature doesn’t mean it’s not doing anything. 
Depends, right? On what you’re making. I like the No Knead Bread; that’s just one giant pre-ferment based on what I’m reading here.
Yep, you got it.
It is just like a big preferment. Note how little yeast is required for the no knead breads; that’s why it can ferment for 18 hours without ruining the dough. All that time lets the enzymes take care of business and develop that refined flavor. The yeast or sourdough then has plenty of time to grow into what is essentially a large enough pitch, so to speak.
That it is also about the easiest way to make bread is a bonus.
I’ve always called it a poolish. And IMO the approach lends itself to making great bread.
That’s what I was thinking too, but it sounds like maybe this is something different?
Eh, whatever. I hope never to become an expert baker like I hope never to become an expert brewer. Too much stuff to learn.
If it’s 100% hydration - that is, the water weight equals the flour weight - it is indeed a poolish. If it is significantly drier, it is called a biga. And you are exactly right; preferments ARE just what can make an ordinary bread into great bread. One with depth of flavor.
I did a poolish for the one I made on Sunday. The flavor ended up really nice.
I baked up two loaves this last weekend, the first with a two hour pre-ferment at 200% hydration and the second the overnight poolish. Last night I sampled what was left of both loaves and not only did the poolish loaf have more depth of flavor but the crumb was much more desirable. The first loaf, although good, was somewhat dense compared to the second one which had a nice balance of “big holes” and “small holes”.