Storing, maintaining, and extending sourdough starter

This info was part of Days 8 and 9 of the making a sourdough starter. I separated it out, so as needed, you can find it easily (without having to remember, "which day did she include maintainence of sourdough in?")

Storing your starter

I'm keeping my starter in the fridge, in a large plastic container, with the lid only loosely screwed on. Sourdough starters should be kept in a large (about 2 quart -- 2 L -- to allow for expansion), non-metal container with some sort of loose covering for the top -- piece of plastic wrap loosely tied on, screw on lid only partially screwed on, or in a canning jar, with folded over cheesecloth secured with a canning band as a lid. Starters produce gas, and need to breath a bit. 

If storing in plastic, make sure you scald the inside of the container before pouring in the starter. Just swirl around some boiling water, pour out and allow to cool. Plastic surfaces grab on to grease, soap and other things you don't want in your starter.

Maintaining your starter

If you can, bake with it once a week. If not, feed it 3/4 cup (180 mL) lukewarm water and 1 cup (110 g) flour, once a week. Leave it out on the counter for about two to three hours, until you can see that it's all bubbly. Then put it right back into the fridge for storage. (If you miss a week, no big deal -- sourdough starters are pretty hearty.) You'll either need to discard some, give some away or use some in pancakes or waffles after one or two weeks, if only feeding it and not baking with it.

When you do bake with it, the feeding process is built in.  Baking with starter is a two-step process.  First, you extend the starter (by adding flour and water), then measure out the right amount for the recipe and refrigerate the rest.

Never add anything other than flour and water to the starter that you keep in the fridge.  Old-timers would add scraps of prepared dough to their starter.  Good way to get sick.

If the starter has a gray, green or brown liquid, this is okay, just stir it in.  If it develops a pinkish liquid, throw it out -- it's taken on an unwanted bacteria.

To extend your starter

The night before you bake with your starter, you will need to extend it (otherwise you'd just use it all up, and all that work getting it started would be for naught).  Think of this as "growing" your yeast.

For a recipe that calls for 2 cups (475 mL) of starter

In a non-metallic bowl, put 1 cup (240 mL) of starter and mix with 2 cups (473 mL) of warm water and 2 1/2 cups (280 g) of flour. Mix thoroughly.  It will be thick and lumpy, but will thin down as it ferments. Cover bowl and set in a warm place overnight. The starter should have become bubbly within a few hours of adding the flour and water.

In the morning, measure 2 cups (475 mL) of starter for your recipe, and put the remainder back in your sourdough pot and refrigerate.  Your freshened starter is now ready to bake with. You will have enough starter, ready to use, for any recipe or combination of recipes that calls for 2 cups (475 mL) of starter (such as the pancake recipe, which calls for 2 cups).

For a recipe that calls for 1 cup (240mL) of starter

If you just wish to do a regular baking of San Francisco sourdough bread (which only calls for 1 cup --240 mL -- of starter), halve the extender recipe -- 1/2 cup (120 mL) starter, mixed with 1 cup (240 mL) warm water and 1  1/4 cups (140 g) flour.

Allow to sit overnight, then measure 1 full cup (240 mL) for your recipe and return the remaining starter to the pot to be refrigerated. Your 1 cup (240 mL) of starter for San Francisco sourdough is now ready to use.

You will find, over time, that you will either have accumulated too much starter in your fridge pot or too little.  The way to remedy with too much is obviously to either give some away or do an extra baking. With too little, just do the half extender recipe, allow to sit overnight in a warm place, and repeat until you have the desired amount of starter.

Look for more recipes to use your starter in the coming days.

*note* this was very long-winded and extensive.  If I failed to make anything clear, please email me.  I can clarify for you and update the post, so it will be clear to others.  Thanks.

To start at the beginning of making a sourdough starter go here