Purchased sourdough starters from King Arthur Flour and Breadtopia.

If you are interested in dipping your toe into sourdough bread baking, for starters you’ll need a starter.

There are many great resources on the web for building a starter from scratch, but I suggest buying one. I outline why in more detail here — Sourdough Focaccia: A Beginner’s Guide — but in short, it’s for ease.

But also because: 

  • If you’re curious about sourdough, get to it! Making a starter from scratch takes weeks.
  • They’re relatively cheap (or free if you get one from a friend or baker).
  • A purchased starter potentially will be stronger/more active than a young, homemade starter.

Where to Purchase a Sourdough Starter

I have had success purchasing and activating sourdough starters from three places:

Each place offer guidance for “activating” the starter. Breadtopia’s instructions live on their website. King Arthur Flour sends along a booklet with details, but also provides online help. Cultures For Health offers video guidance here.

In short, to “activate” each, you simply add flour and water, stir, and wait — that’s all there is to feeding a sourdough starter.

How to Activate a Sourdough Starter

A purchased starter generally arrives in a small bag or container. I’ve created a short video for activating a KAF starter. You can use this same process for activating a Breadtopia starter as well:

Follow these steps to activate it:

  1. Place starter in a vessel. I love these deli quart containers for this purpose.
  2. Add a handful or two of all-purpose flour and roughly an equal amount of water (room temperature tap water is what I use). Stir. If you like being precise: add 45 g each of flour and water. (Note: You may need to add a little more flour or water to get the consistency right, which should be like a thick batter.)
  3. Wait. You may see bubbles and action (rising!) in as few as 6 hours; it may take more like 18 to 24 hours. Variables include the time of year, the temperature of your kitchen, the temperature of your water, how much water and flour you used, etc.
  4. When the starter has roughly doubled in volume, it’s likely ready to go. Drop a spoonful of it in a glass of water. If it floats, you’re ready!
  5. If it doesn’t float after 24 hours, add more flour and water (equal parts), stir again, and wait.
  6. If you aren’t seeing any action after another 12 hours, discard most it it, and add more flour and water (equal parts), stir, and wait. Just be patient. Before you know it, your starter will be rising and bubbling and ready to go.

How to Feed A Sourdough Starter

If your starter floats, and you’re ready to start baking, measure the required amount into a bowl and proceed with the recipe. Here are two great beginner’s sourdough recipes:

  1. Simple Sourdough Focaccia: A Beginner’s Guide
  2. Favorite, Easy Sourdough Bread (Whole Wheat-ish)

If you’re not ready to bake, discard most of it, add an equal amount of flour and water (45 g each or so), stir it together, cover with a breathable lid — these are fun — and stash in your fridge.

From here on out, you’ll need to feed it roughly once every two weeks — I’ve left it for as long as three-four weeks without a feeding, and it has been fine, but I don’t recommend waiting that long in between feedings.

You don’t have to be precise with each feeding and you don’t have to use a lot of flour and water to feed it: a handful of flour, a few splashes of water is all you need. If you like being more precise, use 45 g each flour and water to start:

1. Place the vessel holding your starter on a scale, and add 45 g flour:

feeding the sourdough starter with flour

2. Add 45 g water:

A quart container on a scale holding a sourdough starter, water, and flour

3. Stir together and mark the top of the mixture with a rubber band:

A quart container holding a just fed sourdough starter.

4. Wait until the starter doubles or nearly doubles:

A quart container holding doubled in volume sourdough starter.

5. Test it! If it floats, you’re good to go!

A cup of water holding a spoonful of sourdough starter floating.

Before long, you’ll get the hang of your starter’s rhythm: how it rises and falls, how it behaves when you feed it more regularly, how it behaves when you neglect it, how it smells at various stages, etc.

When you’re ready to bake, the goal is to “catch” the starter at its peak — this is when it is the strongest/most alive. If you miss the opportunity, and the starter collapses, don’t despair: simply discard some of it (or don’t), and feed it again with equal parts flour and water by weight, stir, and set it aside to rise again.

Maintaining a Sourdough Starter

  • Something that deterred me from sourdough for a long time is the waste element: I hated discarding so much and “feeding” so much. I’ve learned over time that there are ways to keep your starter on the lean side to reduce the waste factor. Here’s how:
  • After I use my starter for a bread recipe, I do one of two things: 1. If there is a fair amount of starter left (a half cup or so), I simply stir it up, cover it with a breathable lid, and stash it in the fridge. 2. If there are only a few tablespoons of starter left, I like to replenish it with a very small amount of flour and water (1/4 cup or less of each).  Once I add the flour and water and stir it all together, I cover the vessel with a cloth cover, and stash it in the fridge.
  • Every time I use it or feed it, I discard most of it, and feed it with equal amounts by weight water and flour.
  • When life gets in the way, and I can’t find time for sourdough, I tend to it every 2-3 weeks by discarding most of it, and feeding it with a small amount of flour and water.

Questions? Thoughts? Shoot!