How to Calculate the Cost of Your Sourdough Discard Recipes
If you keep a sourdough starter, you already know the routine: feed it, pour off the discard, and either use it or watch it sit in the fridge. Most bakers treat that discard as free, but whether you bought a starter culture or calculate flour feeding costs over time, the true cost per batch is worth knowing — especially if you bake regularly or want to compare homemade to store-bought.
This calculator breaks your sourdough discard recipe into four cost components: the discard itself, the additional flour, eggs or butter and other mix-ins, and however many servings the batch makes. Enter what you use per batch and get a clear cost-per-serving figure in seconds.
What counts as a sourdough discard recipe?
Discard recipes are any baked goods or snacks that use unfed, acidic sourdough starter rather than fresh-fed active starter. Common examples include:
- Pancakes and waffles — discard gives them a tangy lift that replaces buttermilk
- Crackers — thin and crispy, often the most economical discard use since little other flour is needed
- Banana bread and muffins — discard adds moisture and depth without yeast activity
- Pizza dough — a slower, more flavorful option when you plan ahead
- Flatbreads and tortillas — quick and minimal extra ingredients
Discard cost: free or not?
Many home bakers rightfully consider discard a zero-cost byproduct — it would otherwise be thrown away. If that describes you, enter $0 for the starter cost per kg and the discard portion of your batch cost disappears. However, if you purchased a premium dried starter, receive a commercial starter, or account for the flour used in weekly feedings, assigning a small per-kilogram value gives you a more complete picture.
A useful benchmark: all-purpose flour runs roughly $1.20–$2.50 per kg at major US grocery stores. If your starter is mostly flour and water, a cost of $1.50–$2.00 per kg for discard is a reasonable estimate.
How does homemade compare to store-bought?
A box of sourdough crackers costs $5–$8 for around 8 servings — roughly $0.75–$1.00 per serving. A homemade batch using 150 g of discard, 80 g of flour, and a tablespoon of olive oil can come in under $0.40 per serving. Pancakes from scratch using discard often beat box mix by a wide margin once you factor in the free-discard assumption.
The savings compound quickly when you bake weekly. Even a modest $0.40 saving per serving across two batches a week adds up to over $40 a month.
Tips for reducing your batch cost
- Buy flour in 5 lb or 10 lb bags to cut per-gram flour costs by 30–50%
- Use store-brand butter and eggs — flavor difference in discard recipes is minimal
- Maximize your discard use rate so less goes to waste each week
- Batch cook crackers or pancakes and freeze extras to spread cost over more servings