Scaling recipes (and why salt doesn't double)

How to scale

Tap the serving count at the top of any recipe and pick a new number. Every quantity re-renders immediately. Tap Reset to go back to the original.

You can also set a default servings preference for your household — every recipe opens to that number out of the gate, so you stop scaling "to 2" every single time.

What scales linearly

• Most ingredients — flour, oil, vegetables, meat, dairy.
• Tablespoons, cups, milliliters, grams — all multiply by the scale factor and re-render in the cleanest unit.
• Counts that can be split — 0.5 chicken breast, 1.5 lemons. We assume you can halve or quarter these.

What rounds to whole numbers

Some ingredients are integer-only in a real kitchen. Eggs, garlic cloves, bay leaves, star anise, cinnamon sticks. If the math says 0.38 egg, we round up to 1 egg. If it says 2.4 eggs, we round to 2. The full list lives in the parser; you can't add to it from the app.

What never scales

• Cooking times. Doubling a recipe doesn't double the bake time — that's geometry and thermal physics, not arithmetic. The cook decides whether the bigger tray needs five extra minutes.
• Cookware. Doubling doesn't add a second pan or a bigger Dutch oven. The cook decides what to scale up.
• Ingredients marked with an orange sparkle — see below.

The orange sparkle: non-scaling ingredients

Look for the orange ✦ on an ingredient row. It marks a quantity that's intentionally not scaled — the model decided this ingredient should hold roughly steady regardless of serving size.

The classic case is salt. "1 tsp salt" works for 4 servings of pasta sauce. It also works for 8. It mostly works for 12. Scale it up linearly to 3 tsp salt for triple servings and the dish is inedible. Same logic for:

• Salt, sugar, MSG — anything that seasons by taste rather than by ratio.
• Baking powder, baking soda, yeast — leavening that depends on the chemistry of one batch, not on how many people will eat it.
• Extracts, vanilla, almond essence — flavor backbones that don't proportionally compound.
• Spices in trace amounts (¼ tsp cayenne) — these are taste-tuners.

We mark these at import time, when we generate the .cook file. The model is instructed to write @salt{=1%tsp} (note the =) for any ingredient where doubling the recipe shouldn't double the amount. The app reads that marker and pins the quantity.

Counts vs measurements

When an ingredient has a count (2 onions) we pluralize correctly as you scale — 1 onion, 2 onions, ½ onion. Mass nouns don't pluralize: 2 cups of flour, never flours. Plurale tantum stay plural: 2 stalks of chives, not 1 chive.

Edge cases worth knowing

• Mixed-fraction inputs like 1 ¼ cups are recovered correctly even when the underlying parser stores them as text.
• Above 1 kg, weights snap to 50 g increments so a tripled recipe gives you 1.5 kg, not 1.487 kg.
• Above 1 L, liquids switch to liters and stop offering a kitchen-scale weight option (you can weigh half a liter of milk; you can't weigh two liters).