Kitchen Mysteries is a weekly exploration of oddities surrounding cooking and food. They could be recipes that fail when they shouldn’t, conflicting advice from different sources, or just plain weirdness. If it happens in a kitchen, and you’re not sure why, send a tweet to The Food Geek to find out what’s happening.
Donna asks via twitter:
Bread, to borrow from bread master and author Peter Reinhart, is all about transformation. Everything that we cook has been alive at some point or another, but bread goes through the transformation of alive to dead to alive again many times before it finally makes it to us. You know what? I’m not even going to continue paraphrasing. For some excellent bread information and philosophy, let’s hear it from Mr. Reinhart himself:
What you’re attempting is that much more interesting than even normal homemade bread, because you’re not starting with yeast. Instead, you’re inviting the yeast that’s hanging out in your kitchen and giving it an inviting place to live before you give it some meaningful work to do.
It’s as if you have a halfway house for wayward yeast, and you’re hoping their more varied lives can make for a productive member of society that is far more rich and varied than your garden variety, prepackaged yeast. More importantly, you’re hoping that it makes your bread something special.
There are a few ways that the bread rising process can go wrong, and an extra way or two that is special only for wild sourdough breads. However, all of them revolve around the same issue: for whatever reason, you don’t have enough living yeast producing living yeast by-products.
In a normal bread, the first problem to check for is that your yeast is alive to start with. If you’re using the hardy instant yeast, then by and large you merely have to verify that the expiration date hasn’t passed, and if you’ve kept them in the refrigerator after you’ve opened them, all should be well. If you’re concerned, take a half-teaspoon, put it in some lukewarm water and wait 15 minutes. If you have a bunch of bubbles, all is well. If not, get some new yeast. This won’t help with the sourdough, of course, but it’s worth throwing in.
The second thing to check with normal bread is that you don’t subsequently kill the yeast. The quickest way to kill yeast is to heat it up to around 120°F. This is harder to do with a starter, because the yeast is mixed in pretty thoroughly with some water and flour already, but sourdough starters are potentially more susceptible to lower temperatures, such as around 100°F. To be safe, don’t let the water go above body temperature and you should be carefree.
The third potential problem is aggressive tap water. This isn’t high on the list, but if you’re using a heavily-chlorinated tap water, it’s possible you could kill the yeast. Use filtered water if your tap water smells suspiciously of pool water, but I’m really just covering the bases here.
Okay, now to the sourdough-specific problems. The most likely culprit in this case is that your starter isn’t all that active. Now, there’s nothing inherently wrong with a lazy starter; in many ways, it’s idea, because you don’t want the starter to rise like a bread would rise, or the starter would quickly overtake the kitchen. You want a home for the yeast, not a gymnasium for them.
To use the starter, you want to let it know that it’s time for work to be done. This means giving it more food in the form of water and yeast, then give it time to go. Shirley Corriher suggests in Bakewise to take a 1/4 cup of starter with 1.5 cups of water and 9 oz of AP flour, mix that together, and let it sit for 12 to 16 hours. From there, you can use it as you would any other starter. It should be active and tasty.
Some recipes even suggest that you add a bit of additional yeast into the final dough. I suspect some would consider this to be cheating, and would suggest that the true spirit of the sourdough is to be purely using the wild yeast. Go with your heart on this, but I would not be ashamed to add a bit of extra yeast as long as the starter is doing well. The processed yeast isn’t going to add any bad flavors to the loaf, but you might not get as strong of a flavor.
There are, of course, many care and feeding issues with the creation and maintenance of a sourdough starter that are not covered here. Yeast, left to its own devices, will reproduce until all of the food is eaten and it’s sitting in a pool of alcohol of its own making. Your sourdough yeast are no different, but they also mix with bacteria who have stopped by your halfway house. The bacteria lend the extra acidic flavor, but let the acid mix get too high, and you’ve killed the yeast.
So follow the care instructions for your starter, and keep in mind these few principles of yeast dough management, and you will be rewarded with a bread with all of the wonder and variety that only a fully-realized life can bring you.