The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

sourdough starter waste

pamneuharth's picture

sourdough starter waste

Hi All,  I am making sourdough starter for the first time, using Nancy Silverton's Breads from La Brea Bakery Cookbook recipe.  I'm at the end of day 10 (when you really start feeding it) and I am shocked at the upcoming waste.  I'm supposed to add about 8 cups of flour in the course of a day, then pour off most of it each morning, keeping only 2 cups, for the next 4 days!?!?!?!

Someone please tell me why I need to do it this way?  What's the point of adding so much flour only to throw it out the next day?  Is there some chemical reaction that requires volume? 



squarehead's picture

Without getting too complicated, the short answer is that you are encouraging the development of yeast and bacteria, and they will exhaust their food source and start to die off if their food source (flour and water) is not refreshed. The time frame in which this refreshment must occur is dictated (in part) by temperature but can be maintained with daily feelings if kept at room temp or weekly feelings if refrigerated. You can control the amount of waste by maintaining a small mother culture and having less waste with each feeding. The mother I maintain is 50-100 grams depending on my needs and so my waste is only about 1 cup for the week and I bake a half dozen loaves a week. Hope this wasn't too confusing. Good luck withyour baking. 

pamneuharth's picture

Thanks a lot.  So, as long as I feed it throughout the day I don't need to feed it SO much?  I can give it 1 c water & 1 cup flour 3x/day?  I don't HAVE TO throw out a lot of it?



squarehead's picture

Keep it simple. 20 grams h20, 10 grams starter, 20 grams flour. Feed once every 12 hours. Your startee will be very active, bubbly and sour maintaining it this way. In the morning on days you wish to make a dough, take 40 grams of your stater to build a levain (40 grams levain, 80 grams h20, 80 grams flour), use the remaining 10 grams to re-build your starter. (20/10/20). Then,  10-12 hours later, in the evening, discard 40 grams and keep the remaining 10 grams to re-build your starter (20/10/20). The evening waste of 40 grams is difficult to accept at first but feeding your mom twice a day will keep it very active and healthy and give rise to your bread which is the whole point. And 40 grams of starter is a tiny amount and adds up to about 1-2 cups a week. You can always develop additional recipes to make use of the evening excess starter but that is a lot of bread to consume! Hope this helps. 

placebo's picture

Silverton even mentions in the book that you can halve all the amounts. Even then, it seems the amounts are very wasteful. I don't know offhand if the volume has a significant effect on the starter. I know that many of us keep a much smaller amount of starter and successfully make good bread.

OldWoodenSpoon's picture

"...many of us keep a much smaller amount..."  I keep 5 grams of mature 100% hydration culture to which I add 15 grams of flour and 15 grams of water.  That makes my "stock" quantity 35 grams, and the discard is only 30 grams at each feeding.  It takes several days of twice-daily feedings to save up enough discards for a batch of pancakes.  I never throw away even the discard starter.  Don't be afraid to shrink the quantities down to a more reasonable, and less wasteful, size.

Good Luck

Cooky's picture

I agree that many recipes direct you to make way, way too much starter. I know some people get crazy carried away, and end up with vats of various starters burbling away in the back room.

You can make good sourdough bread with small amounts of starter, so long as the starter gives you the flavor you like. For me, the tricky part is getting the starter to a reliable state of vigor, which takes time and several micro-adjustments.

Once I get to a starter I like flavor-wise, I favor reducing it to a biga-like solid state, which is easier to maintain. A little bit of that can go a long, long way. And it means you're not throwing ridiculous amounts of good-quality flour. Bonus points: The "discard" starter can be recycled into other recipes -- pancake or waffle batter, for instance.

Sycamore's picture

I understand discarding and feeding the stater to maintain a suitable and manageable volume, but why can't you just start with a tsp of flour and a tsp of water and add double the amounts of each for several days? The stater is not increasing drastically in volume yet it is fed each day. I can't see why this would be any different than discarding half each day and replacing the flour and water. 

David Esq.'s picture
David Esq.

As in all things pseudo-scientific, the answers are not clear because people have success in many ways. Some don't bother feeding an established starter for a month at a time, some feed twice a day. 

When starting, some say to discard and some say not to discard. 

And some recipes call for only a tablespoon of starter (say, to create a levain) while others use 2 cups of starter straight up. 

But one thing we can all agree upon is there is no need, when creating a starter, to discard large volumes of anything as there is no need to create large volumes of starter at this stage. 

If someone suggests feeding 100 pounds of water and 100 pounds of flour, feel free to change the unit to ounces and divide by 10. 

ElPanadero's picture

except when first creating a starter.

Pam, what I would do is look at the final quantity of starter the recipe actually calls for in the main dough. Then work back from there to determine the number of feeding stages you need to do WITHOUT ANY DISCARD to get to that point. An example.

Say the recipe calls for 180g starter

I would begin with 20g of active starter

Feed No 1 - 20g starter + 20g water +20g flour making 60g starter (after 12hrs at room temp)

Feed No 2 - 60g starter + 60g water + 60g flour making 180g starter (after 12hrs at room temp)

The actual time left at room temp depends how quickly your starter rises and doubles in size.

So from the above you get from 20g to 180g in 24hrs with no discard.

You always keep back a small quantity of starter to be kept in the fridge, say 20-50g depending how often you bake.

In the above example we are expending 24hrs to build the amount of starter (levain) needed for the recipe so if you want to be baking at 9am one morning, then you start to prepare this levain at 9pm the night before. Simples.

Hope that makes some sense.


dabrownman's picture

I like a 3 stage build that gets to 100% hydration but that is just a matter of preference and i like to refrigerate the levain for 24 hours after the 3rd stage feeding has risen 25% - to bring out more sour and then let it finish its doubling on the counter the next day before using it to make bread.

Many folks just make an extra 25 g of 100% full strength levain add some flour to that to thicken it up and store that in the fridge until the next bake and that is their seed starter for it.   The only problem i have is that if you forget to take the 25 g out before baking it all  y mistake and then - no starter left.  To keep this from happening what I do is to keep 100 g of full strength 66% hydration starter in the fridge and take a small amount of it out to build levain for weekly bakes over  4 seeks using 10-20 g for each loaf of bread

At that time you are down to 10-20 g of stater left and you use that to build it back up to the 100 g of 66% hydration starter for storing int the fridge for 4 weeks.

I call this the no fuss,no muss, no waste starter.  You just want to make sure your starter is mature, full strength, fed with whole grains and at least a month old before doing this.

There are lots of ways to have no waste you just need to choose the one you like the best, are comfortable with and fits your schedule,

Breadandwine's picture

Those amounts do seem rather excessive to me. You can successfully make a starter using 100g flour to 100g water. Then you only have to 'discard' 100g of starter and replace it with 50g flour and 50g water.

I put discard in quotes because you don't need to throw it away - it makes wonderful pikelets (freeform crumpets) turned into a batter and with sultanas or raisins added:

The link takes you to the pikelet method - and to a link to my (not very good) attempt at sourdough. Scroll down to the 12th May.

Doc.Dough's picture

First, Nancy Silverton's Breads of La Brea Bakery is an old book (and to my knowledge has not been updated since its original publication in 1996). I have it; it was my first book about sourdough; I learned a lot from it, and I still bake some of her recipes (Chapeau Rolls) and some that I now bake differently (ciabatta).  But we have learned a lot since 1996 about how to start, maintain, and use a sourdough starter.

For starters (pun intended) I commend you to the Pineapple Juice approach if you insist on starting from scratch. Otherwise, get some from a friend, or buy a sample from King Arthur. Do not buy a dried sample!!!

As noted above, a few grams is all you need to keep as it is enough to begin a build process that will yield a batch of bread in under 24 hrs. And you don't have to save every bit of old starter - if you are keeping a few grams you only need to throw out about an ounce each day when you refresh.

Now about feeding - the twice a day feeding schedule is fine, but there are good reasons to feed only once a day. Your objective in feeding your starter is to return to the original numerical densities of LAB and yeast before you feed again.  This means that you should wait until the full cycle has completed and not feed before the previous batch of food has been consumed.  The LAB are generally in a ratio of about 100:1 relative to the yeast, with about 10E7/g for LAB and 10E5/g for yeast. The growth rate of the LAB is faster than that of the yeast at all temperatures.  The LAB slow down their own growth rate as they produce acid and lower the pH.  At the beginning of the cycle you need to have the pH above ~4.2 or the yeast will grow faster than the LAB and consume all of the food before the LAB population stabilizes where you want it.  The LAB stop reproducing at a pH of ~3.8. The yeast (being insensitive to pH but slower growing) just munch away until they consume all of the available food, ignoring the LAB.  Both are sensitive to salt and even 0.2% salt will markedly reduce the rate of growth and extend the time until the population density  re-normalizes. The yeast stop reproducing when they run out of food. If you don't refresh at a high enough ratio you run the risk of not raising the pH of the refreshed starter above the magic 4.2 value where the growth rate of the LAB exceeds the growth rate of the yeast. This is why I don't like the use of refresh ratios below 1:2:2 (starter: water: flour).

At normal room temperature, you can get a cycle to complete in a few hours if you don't feed very much at each refreshment, but you do need to let it go to completion before you repeat.  I have found that a 24 hr refresh cycle is a very convenient one to maintain since it means that I refresh after dinner each evening (an hour or few one way or the other doesn't matter since everything is stable and in a very slow decline after 24 hrs). My process (1:13:15) takes about a gram of starter from yesterday's refreshment and adds ~13g of water and ~15g of flour, mixes it together, puts on a plastic cap, and lets it sit on the counter (where it won't get any sun) for 24 hrs. In the summer when the kitchen is warmer I use ~0.3g of initial starter, and in the winter when the kitchen is cooler at night I use as much as 3g. Some people will tell you that you run the risk of contamination if you refresh at such high ratios, but I would note that this is in the ballpark of what a real bakery does (once a day, high multiples, room temperature).

If you are interested in more of the science behind this process you can read the references in the (always incomplete) paper available here.


PetraR's picture

My starter lives in the Fridge in a 0.5 litre airtight Kilner Jar.

I have in there 60g of Starter which I do feed with 60ml of water and 60g of flour once a week on a Friday Morning.

My Baking day is Saturday.

I make a leaven to use, that means I work out how much flour I use the next day for baking and use 20% of that amount for my leaven.

20% of 500g of Flour for my recipe is 100g, I dived that by 2 and know I need 50ml of water and 50g of flour to make my Leaven.

I use 1Tbsp of my Water, add the 50ml of Water, the 50g of flour , mix it well, plastic wrap over it, let it sit for 12 hours so I can start my baking in the Morning.

With this way you only need a small amount of starter to keep and you can bake a lot of bread with it:

Per 100g of Flour 1 tbsp of starter to make a leaven.