Brew recipe scaler

How it works

Everything is multiplied by the ratio between the servings you want and the servings the recipe was written for. The capacity check then compares the scaled water against the brewer range you give it, because a number that scales correctly can still be more than the brewer holds.

What the inputs mean

Base servings

How many servings the recipe you are starting from produces.

Brewer capacity

The usable range of your brewer in cups, which is not always what the packaging claims. Both the minimum and the maximum matter.

Worked examples

• Doubling a French press recipe

  • Base 1 serving: 17 g coffee, 280 g water
  • Target 2 servings

  Result: 34 g coffee, 560 g water.

Common mistakes

• Scaling a single-cup pour-over recipe to a litre unchanged

  A deeper bed drains more slowly and extracts differently. Expect to grind a little coarser as the batch grows.

• Scaling below a brewer's minimum

  A brewer running well under its minimum leaves too shallow a bed and channels. The capacity check flags this.

What the result does not mean

• A scaled recipe is a starting point, not the same brew at a different size. Contact time changes with batch size even when the ratio does not.

What this does not account for

• Scales dose and water linearly by servings — real extraction does not always scale perfectly linearly with bed depth and brewer geometry.
• The capacity check compares against the range you enter, not a specific product's exact limit.