Missing an ingredient? Buttermilk: 1 cup milk + 1 tbsp lemon juice or white vinegar per cup. Cake flour: ⅞ cup all-purpose flour + 2 tbsp cornstarch per cup. Baking powder: ¼ tsp baking soda + ½ tsp cream of tartar per teaspoon. Pick what you're missing and every swap is scaled to your amount, with its source and the caveats about texture and flavour.
Best swapMilk + lemon juice or white vinegar
1 cup milk + 1 tbsp lemon juice or white vinegar
Stir, then let stand 10–15 minutes until it thickens slightly and curdles.
Data & method: Each swap names its source — King Arthur
Baking, Colorado State University Extension fact sheet 9.329, a university extension sheet, or
the ingredient's maker — and an automated test pins every sourced ratio to it. 4
common swaps have no published ratio we could find; they are labelled as kitchen conventions. How we calculate →
Tap ↑ Share at the bottom of Safari, then
Add to Home Screen. CrumbCalc then opens like an
app and keeps working with no signal.
Most substitution lists tell you what to swap but make you do the arithmetic when the
recipe needs 1½ cups instead of one. This baking substitutions calculator
scales the whole replacement for you — ask for 3 cups of cake flour and you get the exact
flour-and-cornstarch amounts, not a rule of thumb to multiply in your head mid-bake.
Each ratio comes from a named source, and each swap carries its caveat where one exists. A
milk-and-butter "heavy cream" is fine in a batter but will never whip; a flax egg binds a
muffin but cannot raise a soufflé. Knowing where a substitution breaks is as important as
knowing the ratio.
Working in weights instead of cups? The cups to grams converter
translates any of these amounts into grams for your scale, and the recipe scaler
resizes the whole recipe when you're changing batch size at the same time.
Every substitution, one page each
Each ingredient has a dedicated page with every option, a table scaled to the amounts recipes
actually call for, and the source and caveats spelled out:
For each cup of buttermilk, stir 1 tablespoon of lemon juice or white vinegar into 1 cup of milk and let it stand 10–15 minutes, until it thickens slightly and curdles (King Arthur Baking). Greek yogurt thinned with milk — ⅓ cup yogurt to ⅔ cup low-fat or skim milk — also works, and King Arthur prefers it where buttermilk's flavour matters.
How do I make cake flour from all-purpose flour?
For each cup of cake flour, whisk ¾ cup + 2 tablespoons (⅞ cup) of all-purpose flour with 2 tablespoons of cornstarch (King Arthur Baking). The cornstarch lowers the protein of the mix to mimic cake flour's softer crumb.
Can I substitute baking soda for baking powder?
Yes, with an added acid: ¼ teaspoon of baking soda plus ½ teaspoon of cream of tartar and ¼ teaspoon of cornstarch replaces 1 teaspoon of baking powder; without the cornstarch, use ⅝ teaspoon of cream of tartar (Colorado State University Extension). Baking soda alone won't work — it needs an acid to react with, and it is about four times as strong: King Arthur puts 1 teaspoon of baking powder at roughly ¼ teaspoon of baking soda in leavening power.
What is the best egg substitute in baking?
A flax egg — 1 tablespoon of ground flaxseed with 3 tablespoons of water, left about 5 minutes to gel — replaces one egg (Bob's Red Mill); University of Wisconsin Extension rates it best for breads, cookies and pancakes. ¼ cup of unsweetened applesauce per egg suits cakes, muffins and quick breads. Neither works where eggs are the structure, such as soufflés or custards.
How do I substitute brown sugar with white sugar?
Use 1 cup of granulated sugar plus 2 teaspoons of molasses for light brown sugar, or 1 tablespoon of molasses for dark (King Arthur Baking). There's no need to premix — add both to the recipe together.
Do these substitutions change how the bake turns out?
The best swaps here are close in function; where a substitute behaves differently — heavy cream that won't whip, applesauce adding moisture rather than structure, flour thickening cloudier than cornstarch — the tool says so on the swap itself. Every swap names its source, and the few without a published ratio are labelled as kitchen conventions.
