I’ve had a sourdough starter in my fridge for most of the past twenty years. I got it from my mother-in-law, who purchased a starter at Barkerville, a gold rush reenactment historical site in BC many years ago. I’ve heard of people capturing wild yeast from the air, but never tried doing this myself. If you have, I’d love to hear from you!
The beauty of a sourdough starter is that you can keep it in your fridge indefinitely, even months on end. I keep mine in a glass jar with a good seal (as shown). Glass is good because metal can react with the sourdough, and plastic–well, you know my feelings on plastic. Where I can avoid storing food in plastic, especially long term, I do so.
The old gold prospectors didn’t keep their sourdough in a fridge, but they tended to use it every day. Even now, if you ‘feed it’ and use it daily, you can keep it on your counter. Also prospectors often slept with their starter in order to keep it warm during cold winter nights! The worth of a good sourdough start was legendary.
About 8-10 hours before you want to begin a sourdough recipe, the sourdough start needs to come out of the fridge and be revived. Scrape it into a large bowl (such as a casserole dish), add 2 cups warm water and 2.5 cups of white flour, give it a good whisking, cover, and set in a warm place. I put mine in the oven with just the light on and leave it overnight in most cases.
Anything that comes in contact with the sourdough, be it whisk, spoon, bowl, countertop, should be washed fairly quickly as it dries on very hard and is nasty to get off.
In the morning, it should be fluffy and bubbly. (The photo is of cold unrevived sourdough.) Return one cup to the storage container (which should have been cleaned before it hardened on) and put it back in the fridge. You will now have about 2-2.5 cups of starter to use in a recipe.
Whole wheat flour can’t be used in the sourdough unless you are using it daily. I believe it is the wheat germ in it that isn’t completely absorbed into the sourdough and goes rancid. If, like me, you prefer to use 100% whole-wheat in your recipes, there is a way around this.
When I take my starter out of the fridge I scrape most of it into a casserole dish as above (leaving a couple of tablespoons in my starter container). To the casserole dish, I add whole wheat flour and use all of it in the recipe. To the sourdough starter container, I add 1/2 cup warm water and 1/2 cup + of white flour. Both containers go in the oven with only the oven light on and bubble away beside each other. This way the start remains ‘pure’ white flour and the batch I’m using is pretty much totally whole wheat.
The other way to do it with whole wheat flour is to keep your start out on the counter and feed it (and use it) every single day. This would have been the method our ancestors used.
If you’re interested in seeing some of my sourdough recipes, let me know in comments and I’ll post a few in coming weeks.