As mentioned in the What is sourdough anyway? page, sourdough is a community of wild yeast and lactobacillus bacteria living in a solution of flour and water. Like all living organisms, a sourdough culture needs to be fed to remain alive. The feeding also dilutes the acidity in the culture. If the acidity is allowed to build unchecked, it will reduce the vitality of the starter.

A commercial baker that uses sourdough will feed, or refresh, his culture everyday. He will prepare a sponge to make dough with. Before anything other than water and flour is added to the dough, he will set some aside, and feed it again so it will be ready to make the next day's bread. This is, far and away, the best way to handle a sourdough culture. Feed it daily, and bake with it daily. This keeps the acidity of the culture under control, and keeps both the yeast and lactobacillus bacteria healthy and happy.

Since most home baker's don't bake every day, they have to look for other ways to feed and maintain their starter culture. The classic "olde west" way of handling sourdough deserves mention at this time. Grandma used to keep a crock of sourdough bubbling away on the back of the stove. She'd dip out starter when she needed it, and add water and flour to it as needed. While grandma made great biscuits and quickbreads, the sad fact is that this is not a good way to handle sourdough starter. More than likely, she didn't use it often enough, or enough of it, to reduce the acidity of the starter in the crock. Acidity is created by the bacteria in a sourdough starter, but neither the yeast nor bacteria like it when the acidity gets too high. Using too little of the starter would mean that the starter wouldn't be diluted enough, which in turn would cause the acidity of the starter to rise to a point where the yeast will die off, and perhaps to a point where the gluten of the flour will break down. The acidity would work well with baking soda based quick breads but not conventional sourdough breads. All in all, there is a better way.

The answer is your refrigerator. When your starter is chilled, it will slow down. Instead needing to be fed daily, you can feed your starter once a week or so. Some people feed their starters less often, but that is risky. Sooner or later, your starter can change, and the changes are not always for the better. A wild culture, that is, one that is started with flour and water, has many different strains of yeast and bacteria in it, but one strain if each is normally dominant. If you change the conditions in the starter, which strains are dominant can change. And sometimes the changes are irreversible. In general, as mentioned above, I recommend feeding your stored starter once a week or so. If you are going on vacation and can't feed it for a few weeks or even a month, it will probably be OK if you've been taking good care of it.

I store my starter in quart canning jars. They are cheap, rugged, and easy to find. I don't close the jars all the way so gasses that build up can escape.

Pour a tablespoon of the starter into a mixing bowl. You can use glass, plastic, ceramic or stainless steel mixing bowls. The common belief that starter should never touch metal is largely unfounded. You may have to use a spatula to encourage the starter out of the bottle and into the mixing bowl. Reseal the starter jar and put it back into the refrigerator.

Next, add 1/2 cup of water to the starter. Whisk the water and starter together. Whisking puts some air into the starter, which I feel helps the starter recover from storage more quickly, and also distributes the yeast and lactobacillus bacteria more evenly through the mixture.

Then add 3/4 cup of flour and whisk that in also. (For bakers who measure by weight, this is very close to 100% hydration.) The resulting liquid will be quite thick. You don't need to whisk it until it's absolutely smooth. Remember to put your whisk into water as soon as you are done with it to make your cleanup easier. Since these pictures were taken, I stumbled into flat whisks. They are as effective as the balloon whisk I am using in these pictures, but they are MUCH easier to clean. I try to keep them in stock at Mike's Bread Shoppe, so you might go over there and look at them.

Cover the mixing bowl, and let the starter work for 12 hours or so in a warm, but not hot, place. If your room temperature is between 70 and 80, you can leave your starter on your kitchen counter or on top of your refrigerator. You want it to be safe from kids, pets, spouses and roommates.

If your room is cooler than that, you could put it in your oven with your oven light on. I find that is usually warm enough, and sometimes too warm. Check the temperature with a thermometer. If the temperature in the oven with the oven light on is above 85, you might want to leave the oven door open a bit. Some people report that family members or roommates have turned on the oven to preheat if and destroyed their starter. If your oven has removeable knobs, you might remove the knob and put it into the oven near the starter. That way anyone who wants to turn on the oven will find your starter and hopefully remove it from the oven.

If your kitchen is consistently above 90F, you should look into ways to keep your starter cooler. Mixing it with cold water may be enough to keep the temperature down during the 12 hour cycle. Check your starter temperature before you feed it to see if you were able to keep the temperature under control. The next step would be to keep the starter container in a cool water bath. In extreme cases, you might consider getting a wine cooler or a cheap used refrigerator to keep the starter at a reasonable temperature, between 65 and 85. You can purchase thermostats for refrigerators at brewing supply houses that override the thermostat in the refrigerator and let you set any temperature you want. It is rare that people need to take this step. I use Saran Wrap "Quick Wraps" to cover my starter because they are easy to use, and can be reused easily. If you can't find Quick Wraps, plain old plastic wrap will work fine.

After 12 hours, the starter is ready for its second feeding. This feeding will continue the revitalization of the starter. The yeast and lactobacillus bacteria are waking up, and are becoming more active. At this point, the starter should be frothy and active, but if it was stored too long it might still be sluggish. Add another cup of water to the starter, whisk the mixture, and then add 1 1/2 cups of flour. Cover the starter again, and let it work for 12 hours. At this point, you should have about 3 or 4 cups of starter that are ready to use. If you need more starter than that, feed it again. With each feeding you should double the amount of starter you have. So, the next feeding should use 2 cups of water and 3 cups of flour. The one after that should use 4 cups of water and 6 cups of flour. You should let your starter reach its peak before using it, and use it before it collapses. This window of time is pretty wide, and is somewhere between 4 and 12 hours after feeding, depending on your starter and the temperature of your kitchen.

Take a tablespoon of starter out of the jar and put it in a good sized mixing bowl. You can use a glass, plastic, ceramic or stainless steel mixing bowl. Reseal the jar and put it back into the refrigerator. Add 1/4 cup of water to the starter in the bowl and whisk them together. Add 3/8 cup of flour and whisk again. Cover and let it stand, as above, for 12 hours.

At the end of 12 hours, your starter should be bubbly and alive. Whether it is or not, add 1/2 cup of water and 3/4 cup of flour, whisk it, cover it, and let it work for 12 hours.

At this point, discard all but 1 cup of the starter. To the remaining cup add 1/2 cup of water and 3/4 cup of flour, whisk, cover and let stand for 12 hours. Repeat this step until the starter will double in size between feedings. You are discarding the starter because our goal is to feed the starter enough to double its size. If we keep doubling the starters size at each feeding, it won't be long until you have a swimming pool full of starter. And 12 hours after that, you'll have two swimming pools full of starter. It's cheaper to discard some starter. You may, of course, use the starter you will discard to make pancakes, biscuits, or even bread.

When the starter is active and doubling between feedings, it is time to clean the storage jar, feed the starter one more time, and then - immediately after the feeding - fill your storage jar 1/2 full with starter, reseal the jar, and then put the jar into the fridge. Starter survives refrigeration best if it is fresh when refrigerated. After a while you will have a good idea of how often you need to feed your starter to revive it fully. Too many hobbyists skimp on this step and have a starter that is on the edge of death, that performs inconsistently, and that causes them to give up on sourdough.

While the kind of flour you use to feed your starter is not critical, I find that starters fed on white flour are less trouble than ones fed on whole grain flours. So, I usually feed the starters white flour. I use unbleached and unbromated all-purpose flour. If you find that your starter is producing blander bread than you would like, this usually is caused by an imbalance between the yeast and bacteria in your starter. This can usually be corrected by feeding the starter about 95% white flour and 5% whole grain flour (either whole wheat or rye). This is about 1 tablespoon of whole grain flour in a cup if white flour. It usually only takes two or three feedings to make your culture happy again.

This approach to handling your starter should prevent excess acidity from building up, and should keep your starter healthy. If your starter slows down, perhaps because you left the starter in the refrigerator for a few months too long, you might check out our hints for dealing with slow starters.

If you wind up with more starter than you need, you can use the excess to make Pizza Crusts, or perhaps some Sourdough English Muffins. Or you can give it to a friend and get them started with sourdough.