Tomato Paste & Brix Concentration

Fresh tomato juice sits around 5 °Brix — about 5% soluble solids. To make paste, that juice is boiled (often under vacuum) so water evaporates and the solids concentrate up to roughly 28–32 °Brix. Nothing is added; the soluble solids simply make up a larger share of a smaller, thicker mass as water is driven off.

Because the soluble solids are conserved, paste weight = juice weight × juice Brix ÷ target Brix. The rest is water removed = juice weight − paste weight. So 1000 kg of 5 °Brix juice concentrated to 30 °Brix gives about 167 kg of paste and removes about 833 kg of water. The calculator does this from the weights and Brix you enter.

The concentration ratio shows how much juice each kg of paste used — it's target Brix ÷ juice Brix (the same as juice weight ÷ paste weight). Going from 5 to 30 °Brix is a 6:1 ratio, meaning six kg of juice boil down to one kg of paste. It's a quick way to gauge how heavily you're concentrating.

Trade terms vary, but tomato paste is commonly 28–32 °Brix, with hot-break and cold-break styles. Lighter tomato concentrate (purée) sits lower, around 8–24 °Brix. So-called double or triple concentrates push higher still. The right target depends on your product spec, customer and how it will be reconstituted.

Tomato juice is mostly water — only about 5% is soluble solids. To raise that to 30% you must drive off the bulk of the water, so well over 80% of the starting juice weight leaves as vapour. That's why evaporation energy is the dominant cost in paste making and why heat recovery and vacuum evaporation matter.

The mass of soluble solids stays essentially constant — that's the principle the calculation relies on. What changes is the water around them. Heat does affect colour, flavour and consistency (hot-break versus cold-break processing), but the Brix maths simply tracks the conservation of solids as water is removed.

Yes — rearranging gives juice needed = paste wanted × target Brix ÷ juice Brix. So to make 200 kg of 30 °Brix paste from 5 °Brix juice you need about 1200 kg of juice. Enter the figures and the tool shows the relationship so you can plan how much raw juice to crush for a target paste batch.

Yes — it works for any starting juice Brix and any target paste Brix, in whatever weight unit you use (kg, tonnes or quintals). It also applies in principle to other concentrated products where soluble solids are conserved, though tomato is the classic case.

They're solid planning figures based on conservation of soluble solids. Real plants lose a little solids to fouling, foam and carry-over, and refractometer readings carry small errors, so actual yield runs slightly below the ideal. Measure your incoming juice Brix each batch and use these numbers to plan evaporation load, energy and packing rather than as an exact promise.