Good question, reader Bob! A soaker is pretty much what it sounds like: whole grains, flour, or a combination thereof that’s mixed with water or milk and left to steep for as little as a few hours, or as much as a few days. I suppose the real question is: what’s the purpose of a soaker? There are three possible uses that I can think of. First, to soften whole grains before they’re incorporated into bread to make them easier to chew. That’s probably the number one use among whole grain bakers. Some, however, employ soakers to actually sprout whole grains. Though less common than whole grain breads, sprouted grain breads are gaining popularity these days for their purported health benefits. Sprouted grains also have a different taste than whole grains that haven’t been allowed to germinate. As you may recall from the post below on wheat berries, germination releases enzymes, enzymes which break down long-chain starches into their component sugars. Sprouted grains thus have a sweet and nutty taste that unsprouted grains don’t.
That’s great, Joe, but in case you haven’t noticed, the soaker in the recipe doesn’t have any whole grains in it. What good does soaking do when the grain and it’s embryo have been completely pulverized?
Ah yes, another very interesting question, one that again has to do with enzymes. If you imagine a whole wheat berry as something akin to a little rocket, the embryo (germ) is like the capsule strapped to a giant fuel tank, the endosperm. All it needs to initiate launch is some water, for it’s water that activates the enzymes in the embryo and the endosperm, setting them to work chopping down those big starches into small, consumable sugars (the developing embryo can’t make use of those big starches in their natural state, nor can most bugs or microbes, which is why plants store their seed fuel that way). The thing is, even though milling has mashed the endosperm and the embryo literally to pulp, milling does almost nothing to compromise the integrity of the enzymes. Wet them and they’ll immediately begin their work of dissecting starch, whether there’s a viable embryo to feed or not.
What does that do for a bread dough? Those of you who are familiar with bread baking already know the answer: short chain sugars add sweetness, heighten flavor and add color, especially to the crust where they caramelize in the oven’s heat. All of which is adds up to a pretty good reason to soak flour, yes?