WEEK
19
Playing the Percentages

Alcohol and calculus don’t mix. Never drink and derive.
— Anonymous

Katie had a question.

“Dad, why do I need to know calculus? When am I ever going to use that?”

Good question, Katie. Thirty years ago, during the three years I spent teaching high school math, I heard this question from students a lot (without, ahem, the “Dad”), and my answer hadn’t improved any. The truth was, Katie was never going to use calculus unless she went into a hard-core engineering or scientific field, and even then it was doubtful. Statistics, trigonometry—that was cool and useful stuff. But calculus?

“Because it helps you to understand the world. And it makes you smart, that’s why.”

Maybe even smart enough to understand the baker’s percentage, which is a secret code that bakers use to describe the proportions of ingredients in dough. Every serious bread book touches on it, some books even giving the recipes in percentages in a sidebar or something similar. The baker’s percentage is—oh, let’s have a professional clearly explain how it’s used:

In the case at hand, I have 4,200 grams of leaven sponge, which consists of 2,100 grams of water and 2,100 grams of flour. I subtract 2,100 from 6,402 and I find that I must add 4,302 grams of “flour” (approximately) when I make my dough. This will reduce the amount of white flour I add to 2,380 grams. Similarly, 4,097 minus 2,100 means that I add about 1,997 grams of water. I will still add 128 grams of salt (2 percent times 64).

Any questions, class?

You can see why I was avoiding the baker’s percentage—more than avoiding it; I was deriding it every time I came across yet another reference to it. It seemed both unnecessary and unintelligible, at least until this note arrived:

Bill, certain ratios in your recipe stand out. Your total flour weight is 595 grams, so if you were to hydrate that weight to 68% your water weight would be 404.6 (405) grams. This would be the standard percentage.

Meaning the standard baker’s percentage.

Oh, damn. It was time to learn baker’s calculus. This e-mail from a professional baker had dropped “baker’s percentage” into the conversation as naturally as a baseball manager might drop the phrase “batting average.” I couldn’t avoid it any longer.

I had taken to heart the advice of Lallemand’s Gary Edwards—“You need to ask a baker. An authority”—realizing that even though my breadmaking books were stacking up faster than pancakes (a bread, by the way, technically a griddle-baked quick bread) at IHOP, they didn’t seem to be taking me any closer to my goal. But who could help me with this quest? I wasn’t about to just start knocking on bakery doors.

As I was pondering this, I happened upon an article featuring Steven Kaplan, an American professor of history who, remarkably enough, is respected (if not celebrated) in Paris as an expert on French bread, having written several books in French on the subject.

I found his e-mail address on the Cornell University Web site and sent a note asking if he knew of a baker who might be able and willing to help with my quest for the perfect peasant bread. I foolishly suggested a bilingual baker in France might be acceptable, giving me a good excuse to run over there for a few weeks or months, but his reply, which came from the southwest coast of France, splashed cold Evian on that prospect:

Who? Charles van Over? Never heard of him. The contact info that followed indicated that he lived in neighboring Connecticut. I did some scholarly research* and found that, like both Lallemand and Professor Kaplan, Charles van Over, while not a household name, is apparently well known in the field. His 1997 book, The Best Bread Ever (bakers are not generally known for their modesty), won a James Beard Foundation Award.

I contacted van Over, who responded amenably to my e-mail, in which I detailed my problem with the crumb. He asked for the recipe I was using, and a few days later, his reply, with its casual reference to the baker’s percentage, came back.

Sitting down with a calculator and studying van Over’s comment, “Your total flour weight is 595 grams, so if you were to hydrate that weight to 68% your water weight would be 404.6 (405) grams,” I saw that he simply arrived at 404.6 by multiplying the flour weight by 68 percent. That’s all there was to it?

It turns out the baker’s percentage is actually relatively simple and is used universally in the baking world. It is the ratio of any ingredient in the dough to the total flour, expressed as a percentage. So if you are making a loaf with 100 grams of flour and you use 50 grams of water, the baker’s percentage of water is 50 percent. In the case of water, another way to state this is that the dough has 50 percent hydration.

What’s confusing to those of us who remember any high school science is that, in my example, the water represents one-third of the total weight of the dough (which weighs 150 grams, once you add the water), not one-half, so intuitively it seems that the hydration should be 33, not 50, percent. But the baker’s percentage expresses all the ingredients relative only to the flour, not to the total, so 50 percent is correct.

This is actually a lot easier than computing percentages of the total, because in that case you’d always have to account for how much the ingredient you’re adding is going to affect the new total, which is the kind of thing that saddled me with a C–in undergraduate organic chemistry and is yet another reason why Anne is the doctor in the family, not me. But we needn’t dredge all that up again. Simple as it is, the baker’s percentage can be perplexing when you encounter percentages of over 100 percent (which means there is more water than flour), or when you use it to figure out how much flour to add to a poolish, which itself contains both water and flour.

I understood enough to know that my dough was seriously underwatered. The “standard” 68 percent called for 405 grams of water, and I was only using 345 grams, which gave me a hydration of just 58 percent!

A number of artisan bakers have written that they are making bread with much wetter dough than in the past, and when I mixed up a batch at 68 percent hydration, I could see they weren’t kidding. The dough started out wet and sticky, but after kneading, it started to come together. Still, it was far less firm than my usual dough and would take a bit of practice to get used to.

To be honest, I didn’t see a huge difference in the final loaf, but I was going to get a hands-on lesson. Charlie had invited Anne and me to spend the weekend baking at his home on the Connecticut River. It wasn’t exactly the Seine, but at least the baker and I would be speaking the same language.

À bientôt!