The naive approach (and why it fails)

The first time you double a recipe, the natural instinct is to multiply every ingredient by two and call it done. This works for some recipes and ruins others. The reason is that some ingredients are linear (twice as much pasta means twice as much pasta) and some are not (twice as much salt does not mean twice as much "saltiness").

Most recipe-scaling failures come from doubling the things that don't scale linearly — salt, chili, fresh garlic, baking powder, leavening, lemon. The result is a doubled dish that tastes wildly more aggressive than the original.

What scales linearly (multiply by the factor)

  • Bulk ingredients: meat, fish, vegetables, beans, pasta, rice, grains, broth.
  • Dairy: milk, cream, yogurt, butter, cheese.
  • Fats: oil, butter for sauteing.
  • Eggs (in savory cooking): mostly fine, though you may need to slightly under-beat to avoid extra air.
  • Tomato sauce, broth, wine.

If a recipe uses 1 cup rice and 2 cups broth and you want to double, use 2 cups rice and 4 cups broth. No surprise.

What does NOT scale linearly

  • Salt. Double the recipe, increase salt by about 1.5x and adjust at the end. Going to 2x salt is the most common over-seasoning mistake.
  • Hot chili (fresh, dried, flakes, sauce). Increase by 1.3-1.5x. Heat compounds in larger quantities; doubling makes it overpower.
  • Fresh garlic. 1.5x for doubling. Raw garlic in a doubled recipe goes from "background savoury" to "I can taste the garlic on my breath all night."
  • Strong dried herbs (rosemary, thyme, oregano, sage, bay leaves). 1.3-1.5x. Concentrated flavours.
  • Baking powder, baking soda, yeast. Be careful here — in baking, leavening doesn't scale linearly, and a doubled recipe can over-rise. For doubled cookies and pancakes, multiply by about 1.5x. For breads and cakes, look up the specific recipe.
  • Acid (lemon, lime, vinegar). Slightly less than linear. Increase by 1.5x and adjust at the end.
  • Fresh chili and ginger. 1.5x. Both are sharp and concentrated.

The "halve, taste, top up" rule

When in doubt, follow this rule for any ingredient that I've flagged as non-linear:

  1. Calculate the doubled amount the naive way (just multiply by 2).
  2. Use only HALF of that doubled amount during cooking.
  3. Taste at the end.
  4. Add more if needed, in small increments.

For example: a recipe calls for 1 tsp salt. You're doubling. The naive answer is 2 tsp. The "halve" answer is to use 1 tsp during cooking, then taste at the end and add up to 1/2 tsp more if it needs it. Almost always you end up at 1.5 tsp total — the right answer.

This rule will not let you down. Under-seasoning is fixable; over-seasoning often isn't.

What changes besides ingredients

Pan size

Doubling the volume of a stew while keeping the same pot means a deeper layer of food. This changes cook time. Generally: a doubled stew or soup takes 1.3-1.5x as long, not 2x. Same for braises. The reason is that the surface-area-to-volume ratio shifts, so heat penetrates more slowly.

Cooking time

For sauteing, frying, and stir-frying: cook in batches. A doubled recipe in a single pan crowds, steams, and produces sad food. Two batches at the original size beats one big batch every time.

For braising and simmering: add 30-50% more time, not 100%.

For oven roasting: same time, sometimes a touch longer (5-10 min). The oven temperature stays the same.

For baking: refer to the original recipe author. Cake, bread, and cookie scaling often requires recipe redesign, not just multiplication.

Pan power

If you're doubling a recipe that needs high heat (a sear, a stir-fry), make sure your pan can deliver. A doubled stir-fry in an underpowered nonstick will steam itself. Two pans, or two batches in one pan.

Halving a recipe

Halving is generally easier than doubling, with three caveats:

  • Eggs. Halve a 3-egg recipe by using 1 large egg + 1 yolk, or by beating 2 eggs and using half by volume.
  • Pan size. A halved stew in a giant Dutch oven will cook too fast and reduce too much. Use a smaller pot.
  • Browning. A half-recipe of meat in an oversized pan can steam instead of brown. Use a smaller pan, or cook the meat in a single layer with space.

Salt, acid, herbs, and chili all halve cleanly — you can multiply them by 0.5 the naive way without trouble. Smaller-scale flavours stay legible; the over-concentration problem only occurs in the doubling direction.

The tool, if you'd rather not do mental math

I built a small recipe scaler that handles the linear ingredients automatically and warns you about the non-linear ones: recipe scaler. It's not magic; it's the rules in this guide, applied to a form.

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