Cook with Kre

How to Scale a Recipe Up or Down Without Ruining It

Updated

Here’s how to scale a recipe: divide the number of people you’re feeding by the number the recipe serves, multiply every ingredient by that figure, then check the things that don’t follow the arithmetic, namely pan size, cooking time, seasoning and eggs. Weighing ingredients makes the multiplying easy; checking doneness rather than the clock keeps the result right.

Find your scaling factor

The scaling factor is one number: servings you want ÷ servings the recipe makes.

  • A recipe for 4, cooked for 6: 6 ÷ 4 = 1.5.
  • A recipe for 8, cooked for 2: 2 ÷ 8 = 0.25.
  • A recipe for 6, doubled: 2.

Multiply every ingredient amount by that factor. Write the new amounts next to the old ones before you start, rather than working them out with a hot pan in front of you.

Check what “serves 4” means to the person who wrote it. Some recipes assume hearty main-course portions, others a side dish. If the recipe gives a total weight or a pan size, that’s a better guide than its serving count.

Some apps do this step for you. In Cook with Kre, you choose how many people you’re cooking for before you start, and the plan is made for that number. See how Kre cooks with you.

Multiply by weight where you can

Cups and spoons are awkward to multiply: 1.5 × ⅔ cup is not something you can measure easily. Weights scale cleanly. King Arthur Baking’s ingredient weight chart lists a cup of all-purpose flour at 120 grams and a large egg, out of its shell, at 50 grams, so 1.5 cups of flour is 180 grams with no rounding.

If you only have volume measures, these conversions help:

  • 3 teaspoons = 1 tablespoon
  • 4 tablespoons = ¼ cup
  • 16 tablespoons = 1 cup

Round sensibly. A scaled amount of 1.4 tablespoons of oil is just a generous tablespoon. Precision matters most for leaveners, salt and anything in baking; it matters least for vegetables in a stew.

Bakers often think in ratios to the flour, known as baker’s percentages: every ingredient is expressed relative to the weight of the flour. Once a recipe is in that form, you can make any size of batch by choosing a flour weight and working out the rest.

What doesn’t scale in a straight line

Multiplying the ingredients is the easy half. These are the parts that need judgement.

Pan size. What matters is the area, not the width. An 8-inch square pan and a 9-inch round pan hold about the same, roughly 64 square inches each. Doubling a recipe for one of them needs about 128 square inches, which is close to a 9 × 13-inch pan (117 square inches) or two of the original pans. If the batter or filling sits deeper than the recipe intended, it will need longer in the oven and may stay underdone in the middle.

Cooking time. Time depends on thickness more than quantity. Two chicken breasts take about as long as one, side by side. A double batch of stew in a bigger pot takes longer to come to a simmer. A deeper cake takes longer to set in the centre. Expect times to change, and check early.

Crowding. Double the meat in the same frying pan and it steams instead of browning. Cook in batches, or use two pans.

Evaporation. A wider pan loses liquid faster. A halved sauce in a big pan can reduce too far; a doubled one in a deep pot may need longer to thicken.

Seasoning. Salt, spice and chilli don’t always need the full multiple. When doubling, add less than double, then season to your liking at the end. You can add more; you can’t take it out.

Leaveners and yeast. For modest changes, scale them with everything else. For large batches of bread or cake, look for a recipe written at that size, because rising times and oven heat behave differently in big quantities.

Halving an egg

Halving a recipe that calls for one egg is the classic snag. Crack the egg into a cup, beat it until the white and yolk are fully mixed, then use half:

  • By weight: a large egg is about 50 grams out of the shell, so use about 25 grams.
  • By volume: a large beaten egg is roughly 3 tablespoons, so use about 1½ tablespoons.

Cover the other half, keep it in the fridge and use it soon, in scrambled eggs or an egg wash. When a recipe needs an odd fraction of eggs, such as 1.5, round to the nearest whole egg for cooking and use the beaten-egg method for baking.

Checking doneness, not the clock

Once you’ve scaled a recipe, its cooking times are estimates. Go by the food.

For meat, fish and egg dishes, use an instant-read thermometer in the thickest part. USDA guidance on safe minimum internal temperatures:

  • Poultry, whole or ground: 165 °F (74 °C)
  • Ground beef, pork, lamb and veal: 160 °F (71 °C)
  • Whole cuts of beef, pork, lamb and veal: 145 °F (63 °C), then rest for 3 minutes
  • Fish and shellfish: 145 °F (63 °C)
  • Egg dishes: 160 °F (71 °C)

For bakes, use the recipe’s own signs: a skewer that comes out clean, a top that springs back when pressed, edges pulling away from the pan. Start checking a little before the original time for smaller pans, and expect deeper ones to need longer.

If you’re missing an ingredient for your scaled batch, what to do when you’re missing an ingredient covers swaps by the job each one does. Scaling for a crowd and cooking several dishes? Cook several dishes at once shows how to plan backward from when you eat.

Sources

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