One sleepy morning many years ago I hopped into the kitchen, opened the fridge, and after a blast of cold, awake air, saw a jar of sourdough prep I put out the day before. Due to life circumstances, I couldn't bake with it and in an effort to always avoid leftovers, I put it in the fridge. Well, at that point, it occurred to me that keeping a jar of junk in the fridge at all times might be a good idea – a starter case of sourdough to pull out when I needed it.
Mind you, I'm not a fan of using sourdough starter straight from the fridge. It is very cold, making it a hostile environment for the bacteria and yeasts that inhabit a culture. Over the years, I've tried to keep my starter in the fridge and use it to bake a light, standard sourdough bread that day, but the resulting bread just didn't compare to a well-fed and well-maintained starter with it all room temperature. momentum
But for those days when you're not baking bread or long-fermented pastries, throwing sourdough starters out of the fridge is perfect. You get all the flavor created by the long fermentation, the convenience of having it ready in the fridge, and avoid wasting sourdough starter. Such a starter batch will stay fresher for about two weeks and is the perfect place to get sourdough. starter throw away the cookies, sconesOR pie crust.
Real quick, why is a sourdough starter dump cache useful?
- It's a quick place to turn to throw down, always ready
- It helps avoid waste by saving the engine that would normally be thrown away
- Throwing has a lot of flavor, can use it well
- It's easy!
What is a sourdough starter tossing cache?
I call this a “startup sourdough cache” as an obvious reference to my software engineering days. In computer science, a cache stores data that can later be accessed quickly from fast memory instead of slower hardware memory. I see a starter sourdough cache just like this: Keep a jar of leftovers in the fridge and pull it out when you need quick access to add flavor to whatever you're baking.
But also, the cache serves as a tool for reducing garbage. Throwing away sourdough starters that might otherwise have gone into the compost or trash goes into the cache.
How soon after creating my starter can I create a wipe cache?
If you only have created your sourdough starter, wait until it reliably rises and falls each day with signs of fermentation—some rise, bubbles, a progressive sour flavor—before you cache the remains. Consistent signs of fermentation each day signal that your starter has a stable mix of good bacteria and yeast.
How to store sourdough starter in the refrigerator
Starting with a clean jar, place a piece of tape on the side and write the date two weeks into the future (officially the “expiration date”; see explanation below). Then, every day you feed your starter, instead of tossing the scraps into the compost, add them to the jar, put the lid on, and put it back in the fridge. Weigh some from this jar each time you need to use some in a Sourdough starter tossing recipe and put the covered jar back in the fridge.
How long can I keep the sourdough starter aside?
I generally keep my sourdough toss cache for up to 2 weeks. In theory, you could keep it for much longer, even up to a month, but I've found that after that time, the mixture starts to separate, become overly acidic, and the jar sometimes gets a little funky in general.
After 2 weeks, try to use all the leftovers in the jar. If there is any left over, scrape it into your trash can, clean the jar, and prepare again for a new cycle.
Can I use Sourdough starter to make bread?
I do not recommend using the starter throw it out of the fridge to make sourdough bread. Why? The toss can stay in the refrigerator for several days, up to 2 weeks, which is a long time without feeding in a very cold environment. The mix is likely to be too acidic and will not be properly balanced – in terms of bacteria and yeast populations – for the dough to dry.
My favorite container to hold sourdough starter
As with my sourdough starter, my go-to container for keeping starters in the fridge is a Weck 3/4 liter glass jar. I love that these jars are glass (acidic stuff in plastic is a turn off for me) and very sturdy. Plus, I use them for almost everything in my kitchen anyway.
See more about why I love Weck jars and why they are perfect for beginners and throw away →
See How I Feed My Sourdough Starter
In the video below, you will see how I feed my sourdough starter and how it can be collected and stored in your starter cache.
Use Your Starter Memory: Sourdough Starter Toss Recipes
The recipes below are the perfect place to pull out the sourdough starter, dump the cache, and use right away.
Sourdough Starter Dump Cache FAQ
Can I refrigerate sourdough starter?
Yes! Using a starter sourdough cache, as I like to call it, is a way to store leftover starter over the week or two and use it in recipes when appropriate.
Can I keep my leftover sourdough starter at room temperature?
The longer it sits at room temperature, which is discarded before starting sourdough, the more acidic it becomes until the mixture becomes unsuitable for microbes to function. In the warm room temperature, this happens quickly compared to the colder temperatures inside the refrigerator. I would say after 3 to 4 days, it would become too acidic, start to separate, and have a strong nail polish smell. A very good thing.
What if I think I see mold in my engine dump cache?
If you see fuzzy white, pink, or green in your starter wipes, you've been keeping it too long (be sure to write an expiration date on the jar!). I will throw out the entire cache and create a new one. Thankfully, this isn't your basic sourdough starter and just a toss-up collection—no harm done.
What is expected next?
See ours beginner's guide to sourdough to learn everything you need to know about making, maintaining and using sourdough starter in your baking.
