Short answer: Yes!
Our method is super-fast because it’s based on stored dough, not because we use a full dose of yeast in the recipes. We used full-dose yeast because we knew that many of our readers would want to use the dough within a few hours of mixing it. But if you have more time, you can decrease it by large margins. Half-doses, quarter-doses, and even less will work.
Why use less yeast? Experienced yeast bakers sometimes prefer the more delicate flavor of a dough risen with less packaged yeast. Traditionally, it’s felt that rising the dough very slowly, with very little added yeast, builds a better flavor.
We weren’t convinced of this when we wrote Artisan Bread in Five Minutes a Day–most of our readers value the quicker rise that you get when you use 1 1/2 tablespoons of yeast in our basic recipes. And our flavor is pretty darn good, especially when the dough ages in the refrigerator.
I tried it two ways, first halving the yeast (about 3/4 tablespoon), and then dropping it way down, to 1/2 teaspoon. Both worked, but they work slowly. For the 1/2 teaspoon version, you need to give the dough 6 to 12 hours to rise. And when I rested the 1/2 teaspoon loaves prior to baking, they needed more time there as well, about two hours. The 3/4 tablespoon version needs something in between (about 4-5 hours, and 1 hour rest before baking). Active time is still five minutes a loaf, it’s just your passive resting and rising times that really escalate when you go to the low-yeast version.
Above is a basic white boule risen with 1/2 teaspoon of yeast for the batch, aged to 14 days. It was a bit more temperamental than our basic stuff… you can see that there was more spreading to the sides than we like in our boules. But the taste was a very nice subtle sourdough, with the open crumb structure seen in very traditional rustic loaves.
So if you’ve hesitated to try our method because you like your loaves risen long and slow, give this approach a try.
Low yeast/slow rise with egg-enriched breads: Readers have asked us about the food-safety issues in trying low yeast/slow rise at room temperature with egg-enriched doughs. Raw egg shouldn’t be left out too long at room temp. How long is too long? US Department of Agriculture (USDA) is very conservative on this question (see http://origin-www.fsis.usda.gov/Fact_Sheets/Focus_On_Shell_Eggs/index.asp); they say 2 hours is the max. Understand that this would make it impossible to do a slow-risen egg-enriched dough (though we’ve found that two hours on the counter is enough even for a 33% yeast reduction; problem is when you’re talking about more significant reductions, which require 8 to 24 hours on the counter). The risk is salmonella and other food-borne illnesses. Even though eggs in baked breads are fully cooked, the USDA is clear on this– 2 hours. They’re a very conservative organization– for example, you basically can’t eat hamburger with any pink in it, according to USDA.
One middle-of-the-road approach for egg-based doughs would be to refrigerate at 2 hours regardless of whether the batch has fully risen. Then, allow the completion of rising at refrigerator temperature. It will take 18 to 36 hours.