How do sourdough starters work?


I see people on food network shows talk about how they use a hundred year old sourdough starter for their bread. I don’t understand how it’s reused over and over – is it a matter of how the other ingredients are added? (sorry if i used the wrong tag, wasn’t sure where this fit)

In: 88

It’s a specific species/strain of yeast they’re reusing.

Basically you make a new batch of the same bread recipe, then throw in the chunk of the starter, then your specific strain of yeast infects the new batch, then you can just rip off a chunk of the new batch to be the starter.

It’s a continuous line of the same dough recipe and the same yeast genetics.

It’s not the same exact *piece* of dough for a hundred years. Just the parts that matter.

Imagine you come from a tribe of yeast and bacteria that keeps discovering new dough to live in, generation after generation, for much longer than anyone can remember.

(Yeast don’t remember much, and a hundred years is a long time.)

That’s what it’s like. Don’t ask about what happened to your cousins, after the Other Loaf was split away…

You regularly use or discard some portion, and give the remaining portion additional food(flour and water). You’re creating a situation that’s favorable for the kind of organism you want.

The starter is fed fresh water and flour regularly, which gets eaten up by the bacteria in the starter and then the whole batch is transformed into starter. You take out a portion of that to make your bread or whatever, feed what’s left of the starter, then you have a replenished supply for your next baking need. You keep doing that, and you’re always replenishing what you took out, so it stays alive and never runs out. As long as you’re caring for it, that is.

Starter is like dough without salt and it is colonized with wild yeast. The yeast give it that flavor and every place has their own indigenous wild yeast. If you find a flavor you like, you have to make sure that particular strain doesn’t die off.

The simplest way of doing this, and this is what most people who make it at home do, is make sure you don’t use all the starter. You mix the starter in with the flour and water that you are planning on using for a loaf of bread, but don’t use all of it. Keep a small portion in reserve.

Add more flour and water to the starter, mix it up, and cover it to keep new wild yeast out. That’s it. The starter and the dough you just made will become a new home for an ever expanding colony of the yeast you just introduced.

You can also mix up all the starter with the flour and wait for it to be colonized and then put some of the new dough back. That’s more common in bakeries where they are making huge batches of bread and need as much starter as they can get to kick off the process.