A recipe is a plan written by someone else. Read it like a cook: twice, all the way through, before you touch anything.
Key idea
Read for: the yield, the equipment, the times (including resting and chilling), the temperatures, and the steps that must start early. To scale, find the conversion factor = new yield ÷ old yield, and multiply every ingredient by it.
Why it works
Multiplying is the easy part. Bigger batches need bigger pans and may cook longer; a pot that is twice as wide doesn't take twice the time. Strong flavors (salt, spice, chile) and leaveners are often added at a little less than the full factor, then adjusted by tasting.
Worked example: Scale up
A soup serves 6 and uses 900 g of carrots. You need 20 servings.
- Factor: $20 \div 6 \approx 3.33$.
- Carrots: $900 \times 20 \div 6 = 3000$ g.
Answer: 3,000 g (3 kg) of carrots.
Worked example: Scale down
A dough recipe makes 24 rolls with 1,200 g flour. You want 8 rolls.
- Factor: $8 \div 24 = \tfrac{1}{3}$.
- $1200 \times \tfrac{1}{3} = 400$ g.
Answer: 400 g of flour.
Common mistake
Scaling by adding instead of multiplying, such as adding 2 to every amount to make "a bit more". Ratios break and the recipe fails.
Practice at home
- Pick a recipe from Meal Prep and write its plan: what must start first, what can wait, when the oven goes on.
- Halve a cookie recipe on paper, then bake it. Did anything need adjusting (an egg, the baking time)?
In Meal Prep
- How to read a recipe: the parts of a recipe
- Recipes: every recipe there scales to your household