Winemaking reference
Wine is chemistry you can taste.
6 calculators that show their working. 23 recipes whose gravity, alcohol, acid addition and sulphite dose are computed from the ingredients rather than asserted beside them. And a reference of 54 varieties, 30 styles, 23 yeast strains, 19 faults and 43 cellar additives behind them.
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:
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. Every recipe on this site works its sulphite addition out from the pH of the finished wine for exactly this reason.
Work out yoursRecipes
Recipes that cannot disagree with themselves.
A recipe here stores only what goes into the bucket. The starting gravity is a sugar-mass balance over the ingredients, the alcohol comes from that gravity, the acid addition comes from the measured and target acidity, and the sulphite dose comes from the pH. A grape recipe even takes its harvest Brix from the variety reference, so it cannot claim Cabernet ripens at 19 Brix.
The reference
54
Grape varieties
Harvest Brix, acidity, pH and juice yield as ranges, with what each variety punishes if you ignore it.
Browse grapes →
30
Wine styles
Alcohol, acidity, pH and residual sugar for everything from a pale rose to an icewine, and which of those a law actually sets.
All styles →
23
Yeast strains
Alcohol tolerance, temperature and the nitrogen demand nobody prints, which is why fruit and honey ferments go wrong.
All strains →
19
Faults
Organised by what you can smell, with an honest answer on whether each one can be fixed. Most cannot.
Diagnose a wine →
43
Cellar additives
A typical dose, when to add it and whether it is vegan, for every acid, sulphite, nutrient, fining and stabiliser, with what each one punishes.
Browse additives →