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Winemaking.net

Winemaking reference

Wine is chemistry you can taste.

6 calculators that show their working, 10 varieties with the numbers they actually arrive at, and a fault reference organised by what you can smell.

The number most winemakers get wrong

Free SO2 tells you almost nothing on its own.

How much of your sulphite is actually protecting the wine depends on pH, and the relationship is logarithmic rather than linear. To reach the same protection of 0.8 mg/L molecular SO2:

3.03.23.43.63.82050FREE SO2 mg/L
Free SO2 needed for 0.8 mg/L molecular, by pH. Same function the calculator runs.

A wine at pH 3.2 needs

20 mg/L

free SO2

A wine at pH 3.6 needs

50 mg/L

free SO2

Which is

2.5x

as much, for the same protection

Dosing to a familiar free-SO2 number without looking at pH is how a wine at 3.7 oxidises while its paperwork looks healthy.

Work out yours

Calculators

6

Each names the relation it uses, so a different answer elsewhere is explainable rather than mysterious.

Open them

Varieties

10

Harvest Brix, acidity and pH as ranges, with what each variety punishes if you ignore it.

Browse grapes

Faults

6

Organised by what you can smell, with the honest answer on whether it can be fixed.

Diagnose a wine