How to Fool Yeast

It can’t be that hard, can it? I mean, they’re unicellular organisms. What’s funny to me is how few people have ever thought to do it until recently. One of the results is pain à l’ancienne, though as I said a couple of days ago, Peter Reinhart has since expanded on the technique to create an entire book of recipes based on this sort of retarded (and I mean that in the best possible sense of the word) fermentation.

The principle is as simple as it is ingenious. A dough is prepared using ice water, then immediately put into the refrigerator for an overnight rest. What’s the upshot of this? Those who read me regularly know that a little water is all it takes to activate naturally-occurring enzymes present in flour. As soon as they’re moistened, they go right to work chopping the flour’s long, stringy starch molecules down into simple sugars. Normally, these sugars would be mostly consumed by waiting yeast. However in the case of pain à l’ancienne, those yeast are asleep, put into stasis by the refrigerator’s 40-degree temperature. Since enzymes have no problem with that sort of chill, they go right on working…all night.

The result is a dough with an unusually high proportion of sugar in it. Since the yeasts have been asleep all night, they haven’t been able to consume any of it. That changes when they dough is taken out of the fridge and starts to warm, at which point a massive yeast pig-out gets underway. Three hours later the dough still has a very high proportion of sugar left in it, though it’s risen enough to shape and bake. And is it ever good. The extra sugars give it a very light, nutty-tasting crumb. And then there’s that lovely golden brown crust, created by lots and lots of caramelization.

All in all a startlingly good bread, as well as another demonstration of the many advantages that come with a central nervous system.