In the process of learning how to make sourdough bread and
feeding the starter necessary for it, I was discarding a lot of starter.  That’s just part and parcel of
sourdough.  It has to be fed regularly,
and if you aren’t ready to make bread at feeding time, then you have to discard
some of that starter.  (Or you have to
feed the starter a lot more flour and water and then you have a whole lot of
starter taking up space in the fridge or on the counter, and it just keeps
growing.)

The very initial discards I just threw down the sink.  I was a little too stressed about the starter
itself to worry about anything else.

After I knew I had a strong start going and had made several
very good loaves of bread, I dried the discard (and rehydrated and tested it)
so that if I ever accidentally killed my starter, I would have some dried
starter in reserve.  I never want to be
without this starter again. 

And now that I’ve got a lot of dried starter packed away
with my regular food storage, I need a way to use the discard.  It seems too wasteful to just throw it
away. 

I reasoned that it’s just flour and water, and of course
some minor amounts of bacteria and yeast. 
I thought I could just add it to all kinds of baked goods without
issue.  After all, there are all kinds of
sourdough discard recipes out there. 
However, I wasn’t sure I wanted to start accumulating even more
recipes.  I thought there ought to be a
simple formula for using the discard in recipes I already have and love.

Turns out, I was right. 
“They” say you can use discard in the following ways:

  • As a thickener for soups, gravies, sauces, etc.

  • As a binder for breading chicken or making granola

  • In baking quick breads as well as muffins, biscuits, and
    pizza dough

  • In
    pancakes, waffles, and scones

You’ve
probably noticed that serious bakers weigh their ingredients rather than
measuring by volume.  I find that
bothersome—takes more time and creates more dishes.  And my only scale right now is what the girls
used to weigh their angora rabbits when they were in 4-H.  It’s perfectly clean, but a little on the
large side, especially in the kitchen. 
However, it is highly recommended, at least until you get accustomed to
using the discard in recipes.

Here’s how it’s done:

  • Weigh
    the discard you want to add to your recipe. 
    So as not to throw the flavor off-balance, don’t add more than 200 g of
    discard.  (Just to give you an idea, that
    200 g is going to be about 1 cup.)

  • Divide
    the weight by 2.   

  • Subtract this amount of
    flour and water or other liquid from the recipe.

  • Substitute
    the sourdough discard in place of the removed flour and water.

  • Then
    proceed to follow your recipe.

Most
of our recipes use volume measurements. 
Here’s a link to
a quick reference chart for converting volume measurements to ounces.

Keep in mind that if the discard is replacing milk in a
recipe, you’ll lose out on the milk fat and solids that contribute to flavor
and texture.  You may wish to add some
powdered milk to compensate.   Do not use sourdough discard to substitute for
oil.  It won’t work.

Links to related
posts:

Three Perfect Ingredients Sourdough Bread  

Sourdough Tortillas

References:

https://www.thekitchn.com/using-sourdough-starter-discard-23025996

https://www.pantrymama.com/how-to-add-sourdough-discard-to-any-recipe/

https://food52.com/blog/26178-sourdough-discard-recipes