Several questions from readers over the past week, asking for tips on getting higher rises from their starter-based breads. Seems there are a lot of low, dense sourdough loaves out there, and that’s a common problem when a starter is a bread’s sole raising agent. It’s part of the reason that a lot of natural bakers, back in the 80’s, started “spiking” their doughs with a bit of commercial yeast in the final mixing step. It added a little more oomph to the rise. The purist breadheads went bananas. But that’s another story.
One of the main reasons starter-based doughs don’t rise as high as they could is because many aspiring sourdough bakers don’t manage their starters as well as they could. That is, they let them sit and ripen too long. In the same way a loaf of bread can over-proof, or be left to rise too long before baking (giving the unbaked dough the slack, lifeless feel of a dead fish) starters can be left to work for too long, causing them to use up all their mojo. The yeast in the starter consume too much of the available starch. Even the protein (gluten) in the flour starts to break down. When that happens the loaf is denied the building material it needs to stay aloft, making it impossible for the bread to attain (and then retain) much height.
So what do you do about it? The answer: stay alert to the condition of your starter. Most starters take between three and four hours, on a 70-degree day, to reach reach their peak (shorter in hot weather). After that, just like a loaf of bread, they start to lose steam. “Hey, it’s only an ingredient” you might say, “What does it matter if one component in my bread dough is a little past its prime?”
It matters because starters can comprise up to a third of the volume of a dough. If a full third of your dough is little more than dead weight on the remaining two-thirds of your rising loaf, you’re going to have a pretty flat bread in the end. So you need to take care that your starter is either at — or even below — peak when you make your final mix. Here it helps to have a little experience under your belt, but really there’s not much magic in judging a good starter. It looks like this:
Notice all the bubbles of different sizes, and how the whole thing bulges up around the edges. This is a starter at its peak. This is the stage at which I’d mix it into a dough if I were making a bread that was maybe 15% or 20% starter. If I were making a bread that was truly starter-heavy, up to the aforementioned 33% or so, I wouldn’t let the starter get even this ripe. I’d let it increase in size by maybe 50% or so, and when it just began to dome and show a few surface bubbles, I’d mix it into my dough. That way I’d be sure I hadn’t wasted any of the starter’s rising power.
Sometimes, when I’m building up a large quantity of starter that I won’t use until the next next day, I’ll start with an ounce or so of mother starter and double it, and double it, and double it over the course of the day. When it comes time for the final feeding, I’ll just mix in my flour-water slurry, then refrigerate it without giving it time to rise. By morning the whole thing is a wild yeast powder keg waiting to go off. Slowly.
So there you go, sourdough lovers, my top tip for higher rising sourdoughs. It goes without saying that for the highest rises you want to avoid whole grain flours, as bran and fat (from the germ) undermine rise. But then you’ve been reading Joe pastry for a while, and you knew that already, no?