If you're a casual sourdough baker looking to keep your starter alive and healthy while making the feeding and discarding process as simple and straightforward as possible, read on.
First, I have a confession to make: I killed my first sourdough starter. It arrived in a tiny jar from King Arthur Baking Company's HQ in Vermont where they've been maintaining the same mother starter for over 100 years. I carefully grew it from 1 oz to a healthy 12-ish oz starter which I kept in a ceramic crock in my fridge.
I don't bake with sourdough that often (#unpopularopinion: 90% of the time I just don't think it's worth the hassle and also I'm very impatient), so I'd take it out every few weeks and feed it according to the instructions — "discarding" half of the starter, adding ½ cup water and ½ cup flour to what remained, and mixing it all together before putting it back in the fridge to feed.
If I was going to use it, I'd feed it a few days in a row to get it nice and bubbly, but otherwise, I left it alone in the fridge. Then, one day, when I went to feed it I noticed red dots had spread like an angry rash across its surface and up the walls of the crock. I called King Arthur Flour's baker's hotline, described my symptoms, and got a diagnosis: MOLD. My starter was dead. RIP!
My current sourdough starter, on the other hand, has been thriving for three years now. It's survived nearly drying out and two cross-country flights. It lives in a ceramic crock in my fridge, and I feed it every couple weeks or a few days in a row if I plan to baking with it. I am not good at sticking to schedules, so I just try to remember to do it every few weeks and so far that's worked just fine for me.
If you don't refrigerate your starter then you're probably baking with it once or twice a week, you might feed it once or twice a day, and you probably feed it directly in the container. I am not about that life and I cannot tell you how to live that life. I barely remember to feed my cats some days, and even then at least they remind me. So the advice in this post is probably not helpful for you.
If you're a casual sourdough baker looking to keep your starter alive and healthy while making the feeding and discarding process as simple and straightforward as possible, read on.
how to feed and discard your sourdough starter
When I killed my first starter, I was so confused. What had gone wrong? I had followed the instructions exactly, scooping out and "discarding" approximately half the sourdough starter at every feeding. Yes, it was hard to tell what exactly "half" was, and yes, I was adding the ½ cup flour and ½ cup water right into the crock at feeding time, even though I knew volumetric measurements were wildly imprecise.
But I was following the instructions, so I kept going, even as a little voice in the back of my head whispered: This can't possibly be right. Reader, I should've listened to that voice.
So how do you keep your sourdough starter alive and healthy?
1. Feed your sourdough starter in a clean container, and clean your sourdough crock or container between feedings
It turns out if you don't clean your sourdough crock like, ever, you're gonna get mold. In hindsight, yes, duh. But I was following the instructions! They said to discard half the sourdough starter, and I assumed that meant discarding the half I removed from the container, because why would you take out the stuff you're gonna keep? It just didn't make sense to me!
Now, I know feed my starter in a clean bowl or container and discard (or use) the starter that's left in the container. Then, I clean the container I keep my starter in, and transfer the fed starter back to its home to finish feeding.
Think of the unfed ("discard") starter as an insurance policy. Keep it in its container in the fridge until you see if the newly fed starter in the clean bowl is happy, bubbly, and growing. If it's not, or if something goes wrong with the feeding, you'll still have the discard starter as a backup. When the fed starter is happily bubbling, then you can get rid of the discard and clean the container.
IMPORTANT: Make sure the container is clean AND dry AND that there is no soap or soap residue remaining before you put the fed starter back in. Soap can cause mold, and you don't want mold.
Mold, by the way is usually red and looks like a rash. If you go a week or more between feedings and you open your container and see black/grey liquid collected on top of the starter, that is not mold. It's a naturally occurring alcohol called "hooch" that is produced by the fermentation process. It's also sign that your sourdough starter is hungry. Pour as much of the hooch as you can off the top, then stir your starter before feeding it.
2. Use a kitchen scale to measure by weight to get more control over your starter's hydration level
Measuring flour volumetrically (cups, tsp, tbsp) is wildly imprecise. Depending on how you scoop your flour into a measuring cup, you might see as much as a 1 oz difference in weight. And that can have a huge effect on the hydration level and health of your sourdough starter. So ditch the measuring cup when you feed your starter, and use a kitchen scale instead.
In baking, the hydration of a dough is calculated using what's known as baker's percentage. The amount of flour in a dough is considered 100% and all the other ingredients are calculated as percentages of that amount. So a dough with 1000g flour and 500g water is a 50% hydration dough. The same applies to sourdough starter.
Most sourdough starter has a 100% hydration level, meaning it's made up of a 1:1 ratio of flour to water. Whether you're feeding 1 tablespoon of starter or 4 ounces of starter, what matters is that you're adding equal parts flour and water by weight to it at feeding time.
By feeding your starter in a clean bowl using a kitchen scale, you ensure that 1:1 ratio is balanced. Since your starter is already at a 100% hydration, at feeding time, you simply put however much starter you want (I usually do 4 oz when I'm waking it up from the fridge) in a bowl and add 100% flour (4 oz) and 100% water (4 oz) to it. You could also do 50g starter and feed it 100g flour + 100g water — that would also be a 1:1 ratio at feeding time.
If you're waking your starter up after a few weeks of fridge hibernation, start with a bigger feeding. But if you're feeding it a few days in a row to get ready to bake with it, you can gradually reduce the amount of flour and water you're giving it each day, as long as the amount of flour and water remains equal.
Like I said, I usually do 4 oz of each flour*, water, and starter, but if you prefer to maintain a smaller amount of starter you could do 2 oz of each, and if you prefer to maintain a larger amount, or you want to gift some starter to a friend, you could do 5 or 6 oz of each. Just remember, it will grow at feeding time.
[UPDATE, JULY 2020: I have switched to maintaining a smaller amount of starter and wrote about why and how to do so here.]
The other perk of working by weight is that, say you've measured your 4 oz of starter into the bowl, but then accidentally add 4.5 oz water... all you have to do is "tare" the scale back to zero and add another .5 oz of starter. Then add 4.5 oz flour. (Or, you can just add 4.5 oz flour — as long as your flour to water ratio is equal, it's okay if you have slightly less sourdough starter.) When you're working with cups or tablespoons, it's a lot harder to keep that ratio balanced and accurate.
*Sometimes I feed my starter with equal amounts of whole wheat and AP flour. It's still an equal amount of of flour to water by weight (i.e. 100g water, 50g AP, 50g WW), but I've found that the blend of flours produces a stronger starter.
3. Feed your starter using distilled, purified, or filtered water — anything without chlorine
Chlorine will kill your sourdough starter. Full-stop. Some people swear by fancy, expensive waters, but honestly as long as you run your tap water through something like a Brita filter before you add it to your starter, you should be fine.
I feed my starter straight from the water pitcher in my fridge. Because fridge water is colder, it takes the starter a little longer to start bubbling than if I were to use room-temp water. If you use room-temp water, expect to start seeing bubbles within an hour or so of feeding.
4. Mix your water and starter first, then add the flour
Mixing equal parts water, starter, and flour can be tricky — you're creating a fairly thick mixture, and the flour and starter will quickly absorb the water. You'll have to stir a lot to break up all the lumps of flour and get the three components incorporated evenly.
Combining the water and starter first helps loosen and dissolve the starter. This makes it easier to incorporate the flour. There's much less frustrated stirring involved, and your starter will have fewer lumps.
5. Let your starter sit at room temp for 2-4 hours after feeding and before you transfer it back to its (clean) container in the fridge
Sourdough starter and bread dough are similar in a lot of ways. Warmer temperatures make the yeast more active, and cooler temperatures slow them down. Handle a dough too much and you'll knock the gasses and air bubbles out of it. Same with starter. The stronger your dough is and the stronger the yeast, the more it will be able to bounce back after you knock the air bubbles out. Same with starter.
Letting your starter rest, covered, at room temp (around 70-75 degrees) for a few hours after feeding it gives the natural yeast the perfect environment in which to eat. Your starter will double (or triple) in size and you'll see lots of bubbles visible on the surface.
If you transfer it into the fridge too soon, the yeast won't be active enough to produce lots of bubbles. If you leave it out too long, the yeast will eat everything it can and then stop producing more bubbles. You will have over-proofed your starter.
You don't NEED to keep your starter in the fridge, but if you're a casual sourdough baker and aren't using it too often, it helps slow down the activity of the starter. It can go longer between feedings.
Note: Over-proofing or under-proofing your starter in no way harms it or kills it. It just means you'll likely need to feed it again before you can use it, because you always want it to be active and bubbly when you bake with it.
6. Discarding your sourdough starter doesn't mean you can't use it! Use your discard starter!
Just because it's called "discard" doesn't mean you have to throw it out. And if you do throw it out, please don't put it down your sink; The gluten can build up and cause clogs, especially if you're someone who bakes a lot.
So if you'd rather not let your discard starter go to waste, the number one best thing you can do with it... is use it! King Arthur Flour has a whole library of excellent sourdough discard recipes. I love using it to make sourdough beer pretzels and scallion pancakes which are so easy — you literally just pour the discard into a hot skillet and top it with thinly sliced scallions. So easy. So tasty. So not wasteful.
Recommended tools
- Glass jar or ceramic crock with non-airtight lid. If you're feeding your starter weekly you're fine with an airtight lid, but yeast creates gas while it's feeding so if you feed your starter less than once a week, a container with a lid that lets air out is best. If you do go with an airtight lid, you'll want to "burp" the container every now and then so the gas doesn't build up inside and cause it to explode. The perk of a glass jar is you can see what's really going on inside your starter, not just on the surface.
- Kitchen scale
- Brita filter (or purified/filtered water)
how to feed your sourdough starter
Equipment
Ingredients
- 4 oz 100% hydration sourdough starter (113 grams)
- 4 oz filtered water (113 grams) (equal to or more than the amount of starter, AND equal to the amount of flour)
- 4 oz flour (113 grams) (equal to or more than the amount of starter, AND equal to the amount of flour)
Instructions
- Use a kitchen scale to transfer 4 oz (113g) unfed 100% hydration sourdough starter into a bowl.
- Add 4 oz (113g) filtered or purified water to the starter and mix to combine. The starter will not dissolve entirely, it’s okay if some lumps remain.
- Add 4 oz (113g) flour to the starter/water mixture and use a bowl scraper or spatula to combine. Try to break up any large clumps of flour, but again, it’s okay if some smaller lumps remain. You shouldn’t see any obvious dry spots.
- Cover the bowl with saran wrap or a clean dish towel and let sit at room temp until bubbles form. Depending on how cold your water and starter were at the start, it may take anywhere from 1 to 4 hours for this to happen.
- Meanwhile, clean out the container you usually keep your starter in. Make sure it is dry with no remaining soap residue. Use that discard starter to make scallion pancakes or something. Have fun with it.NOTE: If you’re keeping your unfed starter as a backup, wait to do this until you’re sure the fed starter is bubbly.
- Transfer the newly fed, happily bubbling starter to the clean crock. If not using immediately, refrigerate. If you do plan to use it immediately, leave it out at room temp 6-8 hours (or even overnight) until very, very bubbly.
RECIPE NOTES
- If you haven’t fed your starter for a few weeks, you might see only a few bubbles at first feeding. Feed it two or three days in a row before you plan to use it and you’ll get the happily bubbled starter of your dreams.
- The 4 oz (113g) measurements in this recipe are just one of many, many ways to feed your starter. You can feed 1 oz of starter with 4 oz flour and 4 oz water. You can feed 1 oz of starter with 1 oz flour and 1 oz water. As long as the amounts of flour and water by weight are equal to or greater than the amount of starter, you’re good!
YOUR NOTES
Got more sourdough questions? Suggestions for what to do with discard starter? Leave a comment below!
Victoria
Question: how long after I feed a starter can I bake with it? After four hours? Overnight? What’s best practice?
Rebecca
It depends on how warm the environment is and how warm your water and starter were to start with. Just like with bread dough, cold = a slower rise/fermentation process and warm = a faster rise/fermentation process. The best way to know if your starter is ready to use is that it's doubled in size and is nice and bubbly throughout. If you take a tiny piece of it and drop it in water, it should float. That's when you'll know it's ready.
It also depends on what your recipe calls for. My favorite sourdough bread recipe has you use your starter to create a levain — so it's a small amount of starter (1 tbsp) mixed with flour (75g) and water (75g) to create a really active levain that will do the heavy-lifting in the bread dough. Levain functions kind of like a super-charged starter. This means that you have a little more wiggle room in when your regular starter is "ready" because it's being used to create essentially another starter, the entirety of which will go in the recipe. If your recipe calls for using your active starter right from the start with no levain/poolish, you'll want to use it as close to peak strength as possible.
I'd say anywhere from 12-24 hours after feeding is good, depending on the factors above. If you're planning on using it to bake, consider not putting it back in the fridge after feeding (if the environment isn't too warm) so as not to slow down that process at all.
Bonnie
If I take a cup from my starter to bake with do I need to feed it at that time
Rebecca
If you take a cup out of your starter and you have less than a cup left, I would feed the remaining starter. Don't feed the cup you're going to bake with at the time of baking.
If your recipe calls for a cup of "active" starter then you need to feed your starter anywhere from 3-12 hours in advance of baking with it so it gets nice and bubbly. If your recipe calls for "unfed" or "discard" starter then you can use it without feeding it first, and you'll want to feed your remaining starter (that you aren't baking with).
Naomi
I just want to thank you for clarifying the whole discarding of some of the starter stuff. I was given a starter for Mothers Day and have been watching videos and reading whatever I can to understand the process. No where had I seen/read a reason why you discard some of the starter. The instructions that came with it doesn't even mention discarding. I kept wondering why, and now I know. I'll definitely try the scallion pancake too.
Rebecca
I'm so glad to hear it was helpful!
Renee Jean
When I give discard to friends do you recommend I feed it first and are they on day one or whatever day I’m currently at if during the 1st week?
Rebecca
I usually feed mine at least 24 hours in advance of giving it to friends. It's okay if it's not super active when you give it to them. I usually give about 1-2 TBSP (25-30g) of starter fed at least 24 hours earlier and instruct them to feed it at a 1:3:3 ratio — so 25g starter + 75g water + 75g flour. This will build their starter up quickly to about a cup or so, and then they can choose how to maintain and feed it going forward.
Cameron
Do I always need to feed my starter equal part water and flour? For example if I have 1.5 cup of starter and I want to grow it to give to people or bake with, do I need to feed it 1.5 cups water and 1.5 cups flour?
Rebecca
Yes — and no. To maintain a 100% hydration starter you need to feed your starter equal parts flour and water. But the amount of flour and water can be greater than the amount of starter. So you can feed 25g of starter with 50g water + 50g flour. If you feed the starter less than equal amounts of flour and water by weight, that's a very small meal and your starter won't grow that much. But you can feed just 1 TBSP of your starter a very big meal — a 1:3:3 ratio or a 1:4:4 ratio — to grow it very big so you can gift some to friends. That said, when I give to friends, I usually only give them about 1 TBSP of starter that I've fed within the past 24 hours. I then instruct them to feed the starter with 50g flour and 50g water to grow it up from the small amount, and then they can continue feeding it using whatever method they want.
This is why it's important to discard some of your starter when you feed it — if you just keep feeding the whole starter, it'll just keep growing and growing and need bigger helpings of flour and water to stay active.
You can change the way you feed your starter over time, too. I used to maintain a larger amount of starter, feeding 4 oz starter with 4 oz water + 4 oz flour. These days I only keep about 50g of starter around, and I feed it up really big before baking with it, and then feed whatever small amount is left as my main starter. I hope that helps!
Allison
Hi, I am new to sourdough starter and baking, just to clarify, my starter seems sluggish, not really active, but thick and webby. I feed 1:1:1, 50g starter, ww flour and water, but see no real rise. Should I try less starter and more flour and water? Also, should I use a clean jar each time I discard and feed? Thanks!
Rebecca
Hi! I haven't ever actually built a starter from scratch, mine was a gift from a friend, so I don't want to advise you incorrectly if you're building a starter from scratch. I would recommend looking up new-starter specific resources for that. IF however your starter is a gift from a friend OR already fully mature, then I would recommend taking a tablespoon of it and feeding it a 1:2:2 or 1:3:3 ratio of starter to flour to water in a clean container. Use room temp filtered water and whole wheat or unbleached AP flour if you have it. Save the rest of the starter and feed it the usual 1:1:1 ratio and see how they behave compared to each other. If you leave them at room temp (70F) you should see a rise in the next 6-12 hours or so. Starter will be more active in warmer environments, so you could put it in your oven (OFF) with the oven light turned ON to create a nice warm environment to encourage rising. More important than rise though is if your starter passes the float test — drop 1/2 tsp in a glass of water. If it's active enough, it'll float and you can use it to bake with. Sometimes my starter doesn't look very active and still passes the float test. Other times it looks super active and doesn't float at all. As for whether or not to always use a clean jar, it really depends on the size of your starter and how frequently you feed it. I do the majority of my feedings in a clean bowl so I can clean the jar and then put the fed starter back in the clean jar. But sometimes, if I've used the majority of my starter and there's just about 1 TBSP left in the bottom, I'll feed it right in the jar it lives in and stick it back in the fridge once it rises.
Queen Sean
Thank you for your information, just want to know if the starter made from rye or whole wheat can it be used for bake flour bread? it means that can be used for all breads?Thanks
Rebecca
My starter is 50/50 whole wheat and AP flour — I use it to make whole wheat bread and I've used it to make white bread. From a scientific standard, I think you *can* use it to make any kind of bread — but using rye starter to make a bread that uses all AP flour won't necessarily make it rye bread. I think the hydration matters more than the type of flour. But I'm not an expert in starters made with other kinds of flours so I would suggest reaching out to someone who is! King Arthur Flour's website has lots of helpful resources. 🙂
Jami Feezor
Some recipes say to put in refrigerator and take out to make bread which mean a cup taken out is cold and not fed. Other recipes say feed and leave on counter 8 hours and then take out a cup of starter? Use refrigerator starter or overnight starter?
Rebecca
This is a great question. It really depends on the recipe! Basically, cold = slower yeast activity, warm = more active yeast activity. So you can use it cold or you can use it from room temp, but you'll probably need to adjust the times of your fermentation to account for the yeast waking up from hibernation if you use it cold. Generally I only use it cold right out of the fridge if I'm making a recipe that explicitly says "discard" or "unfed" starter. If it's a recipe that calls for fed or active starter then I feed it and leave it out a room temperature for 12-24 hours before using it.
When I have a recipe that says to feed and leave on the counter for 8 hours what I usually do is use a levain method for creating a cup of starter. I take about 1 TBSP of starter out of the fridge (put the rest of it back in the fridge), and feed that 1 TBSP of starter in a separate container with 100g water and 100g flour. I leave that out overnight and it'll grow into approx 1 cup starter. I measure 1 cup from that and if there's any little bits left, I just add it back to the unfed starter that's still in the fridge. I hope this helps!
Amy
Hi,
I just began to make my first starter and realized I will be going away for 3 days at day 6. Should I halt and start from scratch when I return or refrigerate at day 6?
Rebecca
I’m not sure, tbh — I’ve never made a starter from scratch. My instinct is to say you could *try* refrigerating it. My fear is if you leave it out at room temp it’ll just get moldy. The bacterial culture hasn’t fully matured enough at that point to be able to handle three days at room temp. In the fridge at least you’d be slowing the yeast activity temporarily. If your options are a) start over b) try to put it on hold in the fridge or c) leave it at room temp, it can’t hurt to divide it in half and stick half in the fridge and leave half at room temp. That way when you come back if one of the two methods worked, great! But if neither method worked, well, starting over was always an option anyway. If that doesn’t feel like a good answer and you want better advice from someone who actually had created a starter from scratch I’d suggest perhaps calling along Arthur Baking’s hotline — they’ve helped me troubleshoot my starter before! I’m sure they can give you some good advice.
Rebecca
Once it starts sinking you can feed it again!
Kathleen
Hi there. This is the best explanation of the sourdough process that I've come across. Thank you!
Rebecca
You’re welcome! I’m so glad it was helpful!
Bonnie
Hi! My mother-in-law gave me a start and I misunderstood her and left it on the counter for the last 8 days instead of putting it in the fridge. Will it still be good? She fed it when she gave it to me, but I just don’t know if it’s ok still. Also she uses milk to feed it, should I continue with milk or change to water?
Rebecca
I don’t know — you can take a tablespoon of it and try feeding it, if it grows it might be okay? It depends on how hot or cold your kitchen is. A lot of people leave theirs out so you’re probably fine, but I’ve never used a milk fed starter and don’t know how the use of milk may or may not change how it works! I would look for some resources specifically on milk starters or ask your mother in law what she thinks!
Karen
Hi I had about 1/2 a tablespoon of starter left in my jar, so I added 1/2 cup of each water and wheat flour then the next day I didn’t discard any and added 1 cup of each then my third day I discard 2/3 and then added 1 cup of each it is so bubbly do you think it is good to use?
Rebecca
Yes! That should be fine!
Jane
So, if I want 2 cups of starter for making several loafs of bread, do I build up for a few days? I’m a little confused about discarding half of my starter each time, wondering how I can get to the 2 cups I need. Also, if I am not feeding the discard I am adding to each time I feed , will it go moldy? I have just been putting it into a separate jar.
Rebecca
The reason you discard every time you feed is because otherwise your starter will very quickly grow too big! Every time you feed the starter you need the measurements for water and flour to be at least equal to the weight of the starter. So if your starter is 100 grams, you need to feed it at least 100 grams flour and 100 grams water. That means your starter is now 300 grams. If you don't discard (or use) any of it before the next feeding, you now need to feed your 300 gram starter with at least 300 grams flour and 300 grams water! You'll have a 900 gram sourdough starter, which is a lot!
If you need to scale your starter up for baking, I recommend feeding it at a 1:2:2 or 1:3:3 ratio. Meaning if you're starting with 100 grams of starter, you'd feed it 200 or 300 grams each of flour and water at the last feeding before you plan to bake with it. But until you're ready to bake with it, you don't need to do the really big feeding. You can do smaller feedings (a 1:1:1 ratio) before that. And if your starter is active and bubbly and you feed it regularly, you don't need to feed it many days in a row. That's just if you let it go dormant or keep it in the fridge that you'll want to feed it several days in a row before you plan to bake with it.
You may find my post on maintaining a small sourdough starter helpful — I talk a lot more there about how to scale up your starter for baking. You may also find this post on how to store your sourdough discard helpful too!
Good luck!
Carolyne Pothast
Hi,
so I followed the arthur's king recipe and it calls for 1 cup flour and 1/2 cup of water. However, other recipes differ. is this correct?
Rebecca
The best way to feed your sourdough starter is to measure the flour and water by weight. The weight of 1 cup flour can vary wildly depending on how you scoop the flour. 1 cup of water weighs 240 grams and King Arthur considers 1 cup of flour to be 120 grams (other publications use different weight measurements for one cup of flour), so they are trying to make sure you're getting equal weights of flour and water (half of 240 is 120).
Suzanne
Apologies if you have already answered this question.
If I am maintaining, not using, starter, is there a percentage of the starter that I should discard before I feed it? In other words, how much starter do I discard? Does the amount depend on how much starter I want left to maintain?
Thanks!
Rebecca
It’s not so much about the percentage you need to discard as it is about how much starter you want to feed. When you feed the starter, you should weigh the amount of starter you plan to feed. Then feed it equal amounts of flour and water. So if you don’t want to end up with a huge amount of fed starter, you might discard 90% of the starter. If you do want a huge amount of starter you can feed 100% of the starter! Check out my post about maintaining a small sourdough starter here — it explains the different ways you can customize how much you feed/how much you discard.
Suzanne
Thank you so much for the answer, and for your time.
Alicia
Brand new to sourdough and want to confirm I am doing the right things.
So I take out 100g of starter, mix with 100g water then 100g of flour. Let it sit for - few hours then put in container in fridge. Then I do the same thing for the next couple days since it has been in the fridge for a month. Do I feed the remaining starter one time and put it in a clean jar so when I want to make it again, I use that? Or do I just keep the original starter in the jar and put it back in the fridge? Sorry if this is a dumb question.
Rebecca Eisenberg
Not a dumb question, the process can be confusing! After a few days of feeding just to grow its strength back, feed it so you'll have enough for the recipe plus some "discard" left over. Remove the amount you need from the recipe to use, then feed the discard left in the jar — that will become your new starter. You may find my article on keeping a smaller sourdough starter helpful in terms of how to feed it right before use: https://thepracticalkitchen.com/how-to-maintain-a-small-sourdough-starter/
Nora
I store my starter in the fridge. When I want to use it, if I have maintained the once a week feed, do I need to do any preparation to get it ready to bake? Also, when you are using your starter in a recipe, do you have to use it when it is at its peak or can you use it anytime as long as it is active? Thanks!
Rebecca Eisenberg
If you're maintaining the once a week feed but storing your starter in the fridge you should be able to use it right out of the fridge. It really depends entirely on the recipe you're following and how strong (bubbly and active) your starter is! Most recipes that use starter exclusively for leavening (e.g. don't use any added commercial yeast) require the starter to be at its peak. But some don't! Make sure you read the recipe to prepare your starter appropriately for that recipe's needs.
Wendy
I received some sourdough culture starter as a gift about 2 years ago and and was not really told how often to feed it if you're keeping it in the fridge (i.e. not baking very often) so I didn't even know you had to feed it when it was in the fridge. Nor did I know you had to clean the container every time. The first time I used it and took it out of the fridge it had been in there quite a long time so it had this thick skin on top which I perled off and discarded and then fed the rest. It took a day or 2 for it to come back to life but it did and of course I feed it for a minimum of 5 days before using it and the bread turned out fine. Then I read an article that said you have to feed it at least every 2 months when it's in the fridge so that's what I've been doing but even then it still develops a thick skin on top. I took it out today as I want a bake on the weekend and it had a bit of a skin and I fed it 3 weeks ago. I'm assuming if I switch to a 2 week feeding schedule when it's in the fridge this will not happen? Or is there always a bit of skin that you discard?
Rebecca Eisenberg
I don't know about a skin developing on top...that's not something that usually happens to mine. There's a chance your container is letting too much air in and that's why you're getting a dry skin on top. There are a lot of different ways to customize your feeding schedule, it really depends on how you plan to use it — you may want to try using a different container?