This post is for anyone who wants to learn how to maintain a smaller amount of sourdough starter that can easily be grown into a larger amount for baking.
When it comes to feeding your sourdough starter, there's no one way to do it right. There's only the way that works for you. Of course, there are ways to do it wrong, but that's not what this post is about.
As long as you're using filtered (non-chlorinated) water, occasionally cleaning the container you keep it in, storing it in the fridge, and preventing it from drying out, your starter — big or small — will be fine even if you go a month or two between feedings.
As I've written about before, for a long time I had the same, consistent sourdough feeding routine: 4 ounces of starter with 4 ounces of filtered water and 4 ounces of flour. I fed it every couple of weeks, and a few days in a row before I planned to bake with it. Always the same 4 oz:4 oz:4 oz ratio (a 1:1:1 ratio, for you math nerds out there).
The instructions I got with the starter said to feed it that way, so that's what I did. I didn't want to risk killing my second starter, so I didn't deviate from the system. And it worked pretty well for a while!
But if you do the math, 4 ounces of starter + 4 ounces of water + 4 ounces of flour = a lot of starter!
Few recipes, even discard recipes, call for anywhere near 12 ounces of starter. So when the pandemic hit and flour was harder to come by, I began looking for ways to scale back the amount of starter I was maintaining.
Like everyone else in the world, I learned a lot about sourdough in the early days of quarantine. I read the Tartine bread book, I read Flour Water Salt Yeast, and I read hundreds of posts in various sourdough baking groups on Facebook.
The single most important thing I learned was how to make sourdough using levain. This is the method used to make the standard country loaf from the Tartine bread book. I had baked sourdough with levain before using this recipe from The Kitchn (which is a modified version of a Tartine loaf), but I had just been following the steps. I didn't fully understand what levain was.
Understanding levain changed everything.
Levain (or leavan) is basically exactly the same as sourdough starter, just younger. It's a portion of your mature sourdough starter that you feed and use almost all of in your dough.
Fair warning: I'm going to massively simplify it here, just enough to explain what you need to know to maintain a smaller starter.
To really understand levain you should read the Tartine bread book (or this helpful guide on The Kitchn), which goes into much greater detail about the science and temperatures and different types of bacteria and wild yeast and lactic acids in your starter and how they work.
So here's the short version: When you bake sourdough with levain you take about 1 tablespoon of your mature (fed within the last 24 hours) sourdough starter (25g) and feed it a proportionately larger amount of flour and water — like 100 or 200g of each. It becomes a young, very active, sweeter smelling, more mellow flavored version of your sourdough starter.
If you don't bake with your levain when it's at its peak (which will depend on the temperature of the flour, water, and starter and the ambient temperature) it matures back into, well, mature sourdough starter.
I usually build my levain the night before I plan to bake with it — which means it peaks around 8-12 hours after feeding. But I use cold starter from the fridge, cold water from the fridge, and my apartment is usually cool. If you use room temperature starter, room temperature water, and have a warm apartment, your levain might be ready in as little as two hours.
When you bake with levain, you use almost all of it in your dough. Then you feed the remaining 1 tablespoon or so of remaining levain with equal parts flour and water and it becomes your new mature starter.
It's a much more sustainable sourdough process! And it totally opened my eyes to the unnecessary amount of flour I was using to maintain a massive 12 ounces of starter.
Why feed it a full cup of flour at every feeding when I only needed 1 tablespoon of mature starter to make levain for baking? Especially since I keep my starter in the fridge, and therefore need to feed it a few days in a row before baking with it.
The old way I fed my starter meant I'd often end up with an unwieldy amount of discard. And though I enjoy making sourdough discard scallion pancakes, understanding levain made it abundantly clear that my flour was better put to use feeding the levain when I wanted to bake than it was maintaining a large amount of unfed starter sitting in my fridge.
How to feed your sourdough starter
In the videos below I'm feeding my starter at a 1:2:2 ratio — 30g starter, 60g water, 60g flour. I feed my starter a 50/50 blend of AP and Whole Wheat flour.
Feeding a small sourdough starter is exactly like feeding a larger starter. It's just smaller quantities.
If I'm feeding my starter just because it's been a while and I want to make sure it's refreshed, I'll weigh 1 tablespoon of starter (and discard or use the rest) and feed it using a 1:1:1 ratio. So if 1 tablespoon starter = 25 grams, I'll feed it 25 grams flour and 25 grams filtered water.
But that's just to maintain a small starter. What if you need more to bake with?
scaling your starter up for baking
I keep my starter in my fridge because I don't bake with it that often. Maybe once a month or so.
When I know I want to bake with it, I take it out of the fridge and pour off any hooch (black-ish liquid) that's collected on the top. Then, I measure out 1 tablespoon of starter by weight (25g), and feed it equal parts flour and water and let it sit at room temp for anywhere from two to 24 hours.
This first feeding is a small 1:1:1 feeding just to wake it up from its fridge slumber. I'll discard most of it and feed it again before I bake with it, so I don't want to feed it any more flour than I need to yet.
Depending on how active my starter gets after the first feeding, I might two or three more 1:1:1 feedings over the course of a day or two. Usually it's active enough after the first feeding that I can scale it up at the second feeding.
The last feeding before I bake with it is when I feed it like I'm building a levain. I use just 1 tablespoon of my mature starter, but if 1 tablespoon starter = ~25 grams, I'll feed it 50 or even 100 grams (sometimes as much as 200 grams!) each of flour and water.
Remember, it's all about ratios. So if you measure 1 tablespoon and it's 27g or 30g instead of 25g, that's fine. And you can feed it with 108g flour and 108g water and it'll work just fine, too.
What matters is that the flour and water are equal to each other by weight, and that the amount of each is equal to or greater than the amount of starter. I use whole round numbers like 25g, 50g, and 100g just to keep things simple!
deciding how much flour and water to use
Deciding how much flour and water to add to my 1 tablespoon of starter when I scale it up for baking depends on how much starter my recipe calls for. For a recipe that calls for 200 grams of active starter, I'll feed 1 tablespoon of starter 110 grams flour and 110 grams water. That will grow into slightly more than 200 grams of levain.
To bake, I'll measure out the 200 grams I need for the recipe. This will leave about 1 tablespoon of starter in my container, which I'll feed with equal amounts of flour and water. This becomes my new small starter, which I let feed at room temp for a few hours before sticking it back in the fridge until I'm ready to use it again.
The best part? This method of feeding works whether your recipe calls for levain (like the Tartine's country loaf does) or mature starter. If your recipe calls for mature starter, simply let the levain sit longer before you use it.
accounting for taste
A starter fed at a 1:1:1 ratio will have a more intense sour flavor than a starter fed at a 1:4:4 or 1:8:8 ratio. When the starter makes up a smaller portion of the fed starter, the flavor will be mellower overall. The greater the amount of new flour and new water are in proportion to the amount of starter, the more diluted the sour flavor will be.
If you want to maintain a small starter, but also want your fed starter to have an intensely sour flavor, do your first feeding as a small feeding, but then use ALL of your fed starter in your second feeding.
So your first feeding will be be 25g starter, 25g water, 25g flour (1:1:1). That will give you approximately 75g fed starter.
The next day, in preparation for baking, you'll feed your whole 75g starter with 75g water and 75g flour (also 1:1:1). This will give you approximately 225g starter. If you use 200 grams of that starter in your dough, you'll have 25 grams left which you can feed with 25g water and 25g flour. Boom. Your small starter is back.
small starter discard
What about the small starter discard? Because a smaller starter means smaller discard, I feel less guilty if I throw some out. But if I know I want to make something that calls for sourdough discard, I'll save my small amount of discard in a sourdough container in the fridge and just keep adding more discard to it with each feeding.
I feed my starter a few times in a row before baking with it anyway, so the combined discard from 2 or 3 feedings is usually enough to bake with.
It's totally fine to store that discard in the fridge for several days or even a week or two before baking with it, too. Just remember, the longer it's been since it was last fed the more sour and less active it will be.
In the photo above, the 16 oz deli container on the left is my mature starter. I took 1 tablespoon of starter from there, placed it in the container on the right (labeled: STARTER), and fed it equal parts flour and water. When it's done feeding, it will be about the same size as the starter on the left. It will be my new starter.
The starter on the left is now my discard starter. I can either throw it out, or I can stash it in the fridge and add more discard to it when I feed the new starter (on the right) ahead of of baking with it.
feeding a small sourdough starter
- 25 grams mature sourdough starter (approx 1 TBSP)
- 25-200 grams flour (equal to or greater than the amount of starter, and equal to the amount of water)
- 25-200 grams filtered water (equal to or greater than the amount of starter, and equal to the amount of flour)
- Measure 1 tablespoon (approx 25g) of sourdough starter into a bowl on a kitchen scale. Note the amount by weight in grams.
- To maintain a small starter: Add the same amount of filtered water by weight to the starter. Stir to combine. Then add flour and mix until no dry spots or lumps remain. Let feed at room temperature for an hour or two, then transfer to the fridge.
To scale your starter up for baking
- For a mellow starter (levain): Measure 1 tablespoon (25g) mature sourdough starter into a bowl on a kitchen scale. Add 75g-200g water (depending on how much starter your recipe calls for) and stir to combine. Then, add the same amount of flour by weight as you did water. Stir until no dry spots or lumps remain. Cover and let feed at room temp until it passes the float test.
- For a sour starter: Transfer all of your small, mature starter (75g) to a bowl. Add 75g water, stir to combine. Then add 75g flour and stir until no dry spots or lumps remain. Cover and let feed at room temp until it passes the float test.
- How quickly your starter feeds and when it's ready to bake with will depend on the ambient temperature and the temperature of your starter, water, and flour. Cooler ingredients = slower feeding. Room temperature ingredients = faster feeding. You can always check if it's ready by dropping a small amount in a glass of water. If it floats, it's ready to bake with.
- To calculate how much flour and water to add to your starter when you want to scale it up, take however much starter your recipe calls for, divide it in half and add 20. That number is the amount of water and amount of flour you should feed 1 tablespoon of starter with. You will use most of the starter in your bake, and have about 25-30g of starter left to feed. It will become your new starter.
thank you for posting this; it is so helpful. I too was getting way too much discard--good for the compost barrel but expensive compost. Thanks also for switching from volume to weight. I wish all online sourdough recipes specified that oz is weight and not volume. I noticed though that you change from oz to g, sometimes listing both in the same sentence and sometimes using one or the other. It would be exceptionally helpful to this reader (who was introduced to sourdough baking this summer using grams) to switch all your measurements to grams or at least to cite your weights in both grams and oz, so the reader can understand your information according to how they were trained.
I’m glad this was helpful! I’m not quite sure what you mean by switching mid sentence (I checked through the post and don’t see it, so lmk if I missed it). I was introduced to sourdough feeding using ounces so that’s why some of my explanations for my too-big starter use ounces. That’s just me explaining how I *used* to do things and why it resulted in me having a unwieldy and massive starter.
I have since switched to grams which makes it easier to maintain a small starter because you don’t need to use fractions of ounces. So the rest of my instructions are in grams. But my point with this piece is that whether you use grams or ounces, what matters is that the amounts of flour and water are equal to or greater than the weight of the starter. It doesn’t actually matter the specific numbers or if you’re using grams or ounces. Some people find ounces easier to think about than grams and vice versa.
I could put measurements in both grams and ounces here, but it would kind of defeat the point because you can use either and the specific measurements don’t really matter.
Whether you use grams or ounces, starting by weighing 1 TBSP of starter will give you your starting weight. Sometimes that’s 27g, sometimes 24g. You can do the exact same process with your scale set to ounces. From there you can decide if you want to feed it more flour and water to scale it up or feed it the same amount of flour and water to keep it small. Just stick with grams or ounces throughout the feeding and it’ll be fine.
Most digital scales let you switch your measurements, so if you ever come across a recipe that uses ounces you can weigh the ingredients in ounces and then just switch the scale to grams and it will convert for you.
I hope this is helpful!
I’ve been so intimidated by sourdough and your tips are the only ones that have made sense to me! Thank you!
I’m so glad they were helpful for you!! Good luck on your sourdough journey!
Your explanations are so helpful. Please clarify however:
1) When just doing periodic maintaining of small amount of refrigerated starter:
You mention letting new feed sit out an hour or two before returning to refridge. You dont say to let it sit out for several hours to get it to double in size, but you do say to let it sit out an hour or two. At least one person has recommended I just place it immediately back in refrigerator so it doesn't fully eat the feed, the flour and water you've just added.
Do you think it will still be okay if it doesn't stay out an hour or two and if instead I do just put it right back in the refridge without that "sitting". I'd like your input on this.
2) When you first take the refrigerated starter out to do a small feed, do you let it sit at room temp first for a bit or just make sure you use the 25g or 30g warm water not cold water, with the 25 or 30 g flour?
3) If I plan on feeding my refrigerated starter once every two weeks can I still maintain, feed it with eg 30 g starter, 60 g flour and 60 g water or 30 g starter, 30 g flour and 30 g water?
I would likely keep using the half white whole wheat flour and half bread flour combo for feeding, which is what I always have done. would you find just doing 30 g (combo white whole wheat and 30 g bread flour) (the 1:1:1 ratio, sufficient for feeding just twice a month?)
Sounds like the 1:1:1 gives a stronger sour flavor, which I like. But just using 30 g each is okay?
4) I've been told if I'm unable to feed the starter that is refrigerated for even a month, it's okay. But do I use 1:2:2 or 1:1:1 and should I use 50 g starter to 200 flour and 200 water to feed it after one month or again, can I just use 30 g starter and 30 or 60 each of flour and water?
Hi! I am not a personal sourdough consultant so I can't answer these all in depth. My goal with this post and my other sourdough posts is to encourage you to relax and go with the flow of your starter and not feel so beholden to precise schedules. Many things will "be okay" with your starter if you don't follow all the prescribed rules and routines exactly.
That said, here's some broad answers:
1) Yes that's fine.
2) Either of those situations is fine. What you decide to do depends on your timeline for needing to use the starter.
3) Should be fine, but every starter is different so you'll have to figure out what schedule and ratio works best for you.
4) It's up to you and what you're planning to do with the starter after feeding it. If you're just feeding it to feed it, you may want to do the 1:1:1 ratio. If you're feeding it to build it up to use, you may want to do 1:2:2 or even 1:5:5 ratio.
Thank you so much Rebecca, for this. I really didn't understand the whole starter/levain thing until you explained it. I've read a lot of info online and yours really makes sense to me. I am finding that my loaves have been becoming very mild and lacking that delicious sour taste that I crave. I realized that I was diluting my starter by only feeding and never discarding. Hopefully I am back on track with this. I also love the idea of keeping a smaller starter as I am not fond of the sour taste of sourdough discard scallion pancakes. Strange that my discard made such sour scallion pancakes but I can't taste the sour in my loaves. Another mystery to figure out. If you have any insights on why this might be, I would appreciate it. Thanks again!
Thank you for taking the time to simplify the process of sourdough starts for us beginners. I’m still a little concerned that I’m not fully grasping what to do with the mature starter I feed every week.
1) Do I measure out a new starter from the mature starter every time I feed it, then “discard” the remaining mature starter? Or do I keep the mature starter, feed it periodically and when I am ready to bake measure out a new starter from the “mature” container? Or is that mature starter now my discard?
Yes to both. You measure out a "new" starter from the mature starter every time you feed it, whether or not you're baking with it. The remaining is considered "discard". If you're baking with your starter, you'll measure out the amount you need to bake with, and feed the "discard" and it will become your new starter.
I know it's confusing. You may find reading my article about storing sourdough discard will help you wrap your head around it!