Mass-based formulas

Underneath every formula, BatchDash computes in grams. You can type 2 L of vinegar or 3 cloves of garlic, and the recipe sheet can print liters back at you, but the math in the middle is mass. This page explains why, and how volumes get in and out.

Why mass

A percentage recipe needs one common measure for all its lines, and mass is the only honest one:

• Volume shifts. A liter of hot sauce at 20 °C and the same sauce at 85 °C are different amounts of matter. A kilogram is a kilogram.
• Pieces vary. One habanero weighs 8 g or 15 g depending on the crate. “3.7% salt” means something; “a handful per batch” doesn’t scale.
• Scales are exact. Your bench scale reads grams to the decimal. Measuring jugs read meniscus and hope.

It’s also how professional formulation already works: bakers’ percentages, cosmetic INCI formulas and brewing grain bills are all mass-based. BatchDash just keeps the convention consistent everywhere.

Getting volumes in: density

You still buy vinegar by the liter. Each ingredient can carry a density in g/ml on its record, and any volume you enter converts through it. Cider vinegar at 1.01 g/ml: type 2 L, the formula sees 2 020 g. Count units work the same way through equivalencies: teach BatchDash that 1 clove = 5 g and you can write recipes in cloves.

Getting volumes out: the output density bridge

The same bridge runs in reverse for the batch itself. Your habanero sauce formula outputs liters, but the recipe computes a batch mass. With an output density of 1.04 g/ml:

• Target: 10 L of sauce
• Batch mass: 10 000 ml × 1.04 = 10 400 g
• The 27% vinegar line: 0.27 × 10 400 = 2 808 g, or about 2.78 L at vinegar’s own density
• The 0.3% xanthan line: 31.2 g, which no measuring cup would have told you

Cost per liter uses the same conversion: the batch cost divides over the output mass, then bridges to liters through the density. If a volume-output formula has no density, BatchDash can’t do that last step, so it’s worth measuring once (weigh a known volume of finished product).

What you’ll notice in practice

Formula lines are percentages of batch mass, and the bench back-computes them from the grams you actually weighed. The bill of materials in a run states raw ingredients in their own units, converted from grams. And when a unit can’t be converted (no density, no equivalency), the run warns you instead of guessing.

More on writing recipes this way in formula basics; yield covers the other half of the input-to-output story.