Salt, spice & leavening: the three nonlinear ingredients

Scale a recipe with our calculator and three categories of line get an automatic warning flag. This page is the long version of those warnings — what actually goes wrong with salt, heat and leavening at scale, and the working numbers that keep a big batch tasting like the original.

Salt: scale to 75%, finish by taste

Linear salt scaling fails for two stacked reasons. First, evaporation: a doubled pot of soup doesn’t lose double the water during a longer simmer, so the salt concentration at serving time lands somewhere you didn’t plan. Second, the correction is asymmetric: an undersalted pot is a ten-second fix at the table, an oversalted pot is dinner-threatening. So the rule is simply to put the risk on the recoverable side: when scaling up 2× or more, add 75% of the scaled salt up front and close the gap at the end, tasting.

Two refinements worth knowing:

• Baked goods are the exception — scale salt fully. You can’t “taste and adjust” a baked crumb, there’s no simmer concentrating anything, and salt is doing chemistry (gluten, yeast pacing) as well as flavor.
• Brands are not interchangeable by volume. A teaspoon of Diamond Crystal kosher is 3 g of salt; a teaspoon of table salt is 6 g — double. Cross-brand scaling by teaspoons silently doubles or halves your seasoning. Scale salt in grams:

Chile heat: add two-thirds, then commit slowly

Capsaicin perception is cumulative across a meal — each doubled-batch serving delivers heat against a palate the previous spoonful already sensitized — and dried chiles vary batch-to-batch more than almost any pantry ingredient. A tripled pot of chili with exactly tripled cayenne routinely eats hotter than the original. Add about two-thirds of the scaled amount of cayenne, flakes, fresh chiles or hot sauce, simmer, taste, then close the gap in stages. Heat, like salt, only moves in one direction.

Leavening: linear to 2×, then the pan takes over

Baking powder and soda scale honestly — doubled batter wants doubled leavening. What breaks past 2× is not chemistry but geometry. Leavening gas expands batter upward; a batch big enough to need a much deeper pan sets its edges long before its center, and the center either domes and cracks or slumps when the structure can't hold the rise. The fix is never “reduce the baking powder by some clever factor” — it is keep the batter depth original by splitting across more pans of the original size, and then the leavening math stays boring and linear.

A useful sanity check when a scaled number looks suspicious: classic American cake and muffin formulas hover near 1 to 1¼ teaspoons of baking powder per cup of flour (or ¼ tsp of soda per cup, when there's an acid to react with). If a scaled recipe drifts far outside that band, something upstream went wrong — usually a typo in the original.

Yeast: scale the amount, not the schedule

Yeast scales linearly with flour, but a doubled dough in one mass runs slightly warmer in its core (fermentation makes heat) and can outpace the recipe's clock. Judge every rise by volume — doubled in size — never by minutes. One packet is 2¼ tsp ≈ 7 g, a number that makes packet math easy at any scale.