One sleepy morning many years ago I went into the kitchen, opened the refrigerator and, after a breath of cold, waking air, I saw a jar of sourdough that I had put in the day before. Due to life circumstances, I couldn’t use it for cooking and, in an effort to always avoid waste, I put it in the refrigerator. Well, at that moment, it occurred to me that keeping a jar of scraps in the fridge at all times might actually be a good idea: a supply of sourdough to draw from when I needed it.
Mind you, I’m not a fan of using sourdough straight from the fridge. It’s too cold, making it a hostile environment for the bacteria and yeasts that populate a culture. Over the years, I’ve tried keeping my starter in the refrigerator and using it to bake a simple, standard sourdough loaf that day, but the resulting bread didn’t compare to a well-nourished, maintained starter with all its room temperature. force.
But for those days when you don’t have to bake long-fermented breads or desserts, discarded sourdough from the refrigerator is perfect. You get all the flavor created by the long fermentation, the convenience of having it ready in the refrigerator and you avoid wasting the sourdough starter. Such a starter supply will stay fresher for about two weeks, and is the perfect place to draw from for unwrapping cookies, scones, a lemon tart or pie crust.
Really quick, why is a sourdough starter waste cache useful?
- It’s a quick place to turn to for initial scraps, always ready
- Helps avoid waste by saving goodwill that would normally be thrown away
- Waste has a lot of flavor, you might as well put it to good use
- It’s easy!
What is the sourdough starter waste cache?
I call it the “sourdough starter cache” as a tongue-in-cheek reference to my software engineering days. In computing, a cache stores data that can later be quickly accessed from the fast cache rather than from slower hardware memory. I see a sourdough starter cache exactly like this: Keep a jar of accumulated scraps in the fridge and pull it out when you need quick access to a flavor boost in whatever you’re baking.
But caching also serves as a means to reduce waste. Sourdough scraps that would otherwise end up in the compost or garbage instead end up in the cache.
How long after creating my Starter can I create a scrap cache?
If you’ve just made your own sourdough starter, wait until it reliably rises and falls each day with signs of fermentation (some yeast, bubbles, a progressive sour aroma) before caching the scraps. Consistent signs of fermentation every day signal that your starter has a stable mix of good bacteria and yeast.
How to store sourdough scraps in the fridge
Starting with a clean jar, place a piece of tape on its side and write the date two weeks in the future (officially the “use by” date; see explanation below). So, every day you feed your starter, instead of putting the scraps in the compost, add it to the jar, put the lid on it and put it back in the refrigerator. Weigh out some of the scraps from this jar whenever you need to use some in a sourdough scraps recipe and place the covered jar back in the refrigerator.
How long can I keep sourdough scraps?
Typically, I keep the cache of sourdough scraps for up to 2 weeks. In theory, you could store it much longer, even up to a month, but I’ve found that after this time the mixture starts to separate, becomes overly acidic, and the jar sometimes becomes a little weird overall.
After 2 weeks, try using up all the scraps in the jar. If any remains, scrape it into the compost bin, clean the jar and prepare it again for a new cycle.
Can I use sourdough scraps to make bread?
I don’t recommend using sourdough starter scraps from the refrigerator to make sourdough bread. Why? The scraps may remain in the refrigerator for several days, up to 2 weeks, which is far too long without being fed in an environment that is too cold. The mixture is likely overly acidic and will not be adequately balanced, in terms of bacteria and yeast populations, to leaven the dough.
My favorite container for holding sourdough scraps
Just like with my sourdough starter, my favorite container for storing sourdough starter waste in the fridge is a 3/4 liter glass Weck jar. I love that these jars are glass (acidic things in plastic disgust me) and very durable. Plus, I use them for everything in my kitchen anyway.
Find out more about why I love Weck jars and why they’re perfect for your starter and discard →
See how I feed my sourdough starter
In the video below you will see how I feed my sourdough starter and how scraps can be collected and saved in the sourdough starter cache.
Use your starter cache: recipes to discard sourdough starter
The following recipes are the perfect place to pull out your sourdough starter supply and use it immediately.
Sourdough Scrap Cache FAQ
Can I store sourdough scraps in the refrigerator?
YES! Using a sourdough starter cache, as I like to call it, is a way to store sourdough starter scraps for a week or two and use them in recipes when it’s convenient.
Can I store sourdough scraps at room temperature?
The longer sourdough waste remains at room temperature, the more acidic it becomes until the mixture becomes inhospitable to microbes to function. At warm room temperatures, this happens quickly compared to colder temperatures inside the refrigerator. I would say after 3 or 4 days it would become overly acidic, start to separate, and have a pungent nail polish-like aroma. Too much of a good thing.
What if I think I see mold in the initial scrap cache?
If you see a fuzzy white, pink, or green color in your initial discard cache, you’ve kept it too long (be sure to write an expiration date on the jar!). I would like to delete the entire cache and create a new one. Thankfully, this isn’t your main sourdough starter, but simply a collection of scraps, no harm done.
What’s next?
Check out our guide to sourdough starters to learn everything you need to know about creating, maintaining and using sourdough starters in your desserts.
