I like to make sourdough bread on occasion, but I'm not up for feeding and caring for a starter all of the time.  Is there some way that I can save the starter for times when I want it?

-- Ruby

The first step in making sourdough bread is to make a starter.  Basically, a starter is similar to a pre-ferment (see Bread Pre-ferments), except that the yeast in a starter is kept alive continuously by feeding it on a regular basis.  Feeding is done by stirring in equal parts flour and water.

Starters can be made from scratch, using the wild yeasts that are in the immediate surroundings or from pre-packaged sourdough yeast packages.  Wild yeasts are in the air and on the ingredients and utensils you work with every day.  Except in making a sourdough starter, they are generally not important in everyday cooking.

If you are making a starter from scratch, it takes about a week of care before it is ready to use.  On the other hand, if you know someone who regularly makes sourdough bread, chances are you can beg a cup of starter from them. If a starter is made from a pre-packaged yeast, it will be taken over in time by the local wild yeasts.  Some areas have wild yeasts that make a particularly good tasting bread, such as the famous San Francisco sourdough.

Sourdough starter can be kept in the fridge, which slows down the yeast, but it still has to be fed every few days.  If it is not refrigerated, the starter has to be fed a few times a day.

When the baker is ready to make bread from the starter, it is fed and allowed to warm up to room temperature, if it was refrigerated.  Part of the starter is used in the bread and some or all of the rest is fed again and returned to the fridge, if desired.

For the occasional baker, keeping a starter alive is both time consuming and wasteful, since each time that the starter is fed half or more is thrown away.  The alternative is to save some of the starter for future use, either by freezing or drying it.  It takes a day of lead time before making a batch of bread to reactivate the dried or frozen starter.

I have had reasonably good luck drying a thin layer of starter on a rimmed sheet pan in a just barely warm oven.  After the starter is completely dry, crumble it up and store it in a sealed container or zippered bag.  Lining the pan with parchment or waxed paper makes things easier.

In her book Cookwise: The Hows and Whys of Successful Cooking, Shirley O. Corriher suggests that if you are going to freeze starter, adding a small amount of flour and water just before freezing may be beneficial.  Freeze the starter in an ice cube tray so that you can take out as much as you need.  Corriher suggests always freezing some of your starter each time you begin a new one from scratch, just in case it happens to be a particularly good batch.

If the starter was dried, add 1/4 cup of the dried starter to equal amounts of flour and water and keep it at room temperature.  After six or so hours, add 3/4 cups each of flour and water.  Six hours later, discard about a third of the starter and feed it again with 3/4 cups each of flour and water.

To use frozen starter, mix a slurry of 3/4 of a cup each of flour and water and put in several of the cubes of the frozen starter.  Stir occasionally until the starter is completely melted.  It may be necessary to feed it once or twice more at six hour intervals, as above, before proceeding.

When you run low, divide and feed the starter as you would if you were going to keep it alive, and then freeze or dry what isn't used for bread.