Yes, you generally must discard a portion of your sourdough starter before each feeding to control its size, maintain a healthy yeast/bacteria balance, and prevent needing an unmanageable amount of flour; otherwise, it becomes too acidic, weak, and massive. This "discard" isn't wasted; it's the part you save for recipes like pancakes, waffles, and crackers.
The good news is you can avoid discard altogether if you feed your sourdough starter as you bake. Meaning you create the exact amount you need while simultaneously keeping enough starter to keep going.
The biggest mistake with a sourdough starter is impatience, primarily by using it before it's strong enough (weak starter) or discarding too much/feeding inefficiently, which weakens it further, leading to flat bread; you must give a new starter weeks to mature and consistently feed it at its peak for proper leavening power. Other common errors include using chlorinated water, incorrect water temperature, or ignoring temperature for sluggish activity.
I learned one way and that's what I do. I have a discard jar in my fridge, and I continue to add to it. If it gets some hooche on top, I just pour it off and use.
Why You Must Discard Some of Your Sourdough Starter Before You Feed It. If you don't discard your sourdough starter, it will grow too big and be unmanageable. Not to mention you will go through an unmentionable amount of flour. Let's say you start with 50g of flour & water on day 1.
An overfed starter can be too diluted and it will be very watery. Your workers are there, they are just overwhelmed with too much food and water.
Yes, you should always stir your sourdough starter thoroughly before discarding any portion of it; this ensures that the yeast is evenly distributed throughout the starter before you remove a portion to feed and the rest to discard. The same goes for using it.
Premature discarding and overfeeding will weaken your starter and elongate the process. Don't discard and re-feed a weak starter before it shows increasing bubble activity or height from the previous feeding. If you don't see more bubbles or a faster rise each day, skip a feeding, and give it more time.
Discard generally refers to the portion of starter you remove during feedings to maintain the balance of flour and water. You can save this discard in the fridge for later use. If you're baking with "hungry" starter, keep in mind it may have a stronger sour flavor due to the fermentation time.
The 1:1:1 method for sourdough starter is a feeding ratio using equal weights of starter, flour, and water, typically measured in grams (e.g., 50g starter + 50g flour + 50g water) to refresh it, promoting quick activity and preventing excessive sourness, ideal for regular maintenance or when needing a fast-rising starter. This low ratio means less food, so microbes consume it quickly, causing the starter to peak (double in size) faster, often within 3-4 hours at room temperature.
Sourdough (leaven) appears in the Bible primarily as a metaphor for growth, corruption, or the pervasive nature of the Kingdom of God, notably in Jesus's parables (Matthew 13:33, Luke 13:21) where a small amount of leaven affects all the flour. It's also significant in the Exodus story, where God commands Israelites to eat unleavened bread (matzah) to commemorate their hasty departure from Egypt, symbolizing a break from Egyptian mastery of sourdough. While not a daily staple in the religious narrative, its presence highlights themes of spiritual transformation, hypocrisy (the "leaven of the Pharisees"), and foundational religious practices like Passover.
Signs of an Overfed, Weak Starter
So what is “discard?” Sourdough discard is the part of the starter you GET RID OF every time you go to feed it. If I kept my entire starter and fed it time and time again, I would end up with WAY too much starter that I would have to find a use for.
The biggest mistake beginners make with sourdough is impatience, specifically baking with a starter that isn't strong enough or rushing fermentation, leading to flat, dense bread; they often try to bake too soon, don't let dough proof long enough, and fail to develop dough strength or learn to "read the dough" (look/feel) rather than just the clock, plus starting with overly high hydration is a common pitfall.
Wide-mouth jars are best for growing, feeding and maintaining sourdough starters. Over the lifetime of your starter, you will need to remove a lot of starter from the jar as well as add a lot of flour and water. If you have a narrow-mouthed jar, the small opening will make feeding and caring for your starter messier.
If I want to start preparing the dough first thing in the morning, I feed the start last thing in the evening before going to bed. In case I am not able to prepare the dough any longer as per the plan, I would pop the starter in the fridge and use it later in the day, without an additional feed.
If you bake a lot of sourdough treats you may choose to keep your starter on the counter, at room temperature. While this means feeding it twice a day, it also means your starter's always ready to go when you are.
There is no single best ratio, but I've found a ratio of 1:5:5 fed twice daily at 12-hour intervals to produce a sourdough starter that's strong and healthy. This ratio corresponds to 20% ripe starter carryover, 100% water, and 100% flour (a mix of whole grain rye and white flour) at each feeding.
However, if you bake couple of times a week or once a week, best to move the starter in the fridge. You would then remove it from the fridge for feeding ahead of preparing the dough. Can I leave my starter out overnight? Yes, if you have just fed it.
You need the carry over to keep the starter going, but too much of it means discard. 🌾You also want the little extra to carryover, to keep the starter going. 20-30g should be sufficient, even as little as 5/10g if you feed your starter every day or every second day.
Simply put: a sourdough starter is a live fermented culture of flour and water. Once it's fed with additional flour and water (and left in a warm spot to rise, ideally 75+ F), it becomes bubbly and active. A small portion of this active starter is used to make bread dough rise.
Your sourdough starter should be bubbling and rising up the sides of its container within 4 hours of feeding (always keep your starter in a container that has plenty of room for expansion!).
Overfeeding a sourdough starter will put the culture out of balance. When you don't feed your sourdough starter enough, it will become very acidic because you aren't giving it fresh flour or fresh water and the waste will build up inside the jar.
This is the second proofing stage which can take anywhere between 12-48 hours. The longer you proof the dough, the more acidic it will become, and the more the gluten will be broken down.