Free tools for winemakers
Wine blending calculator
Several lots into one: volume, alcohol, TA and sugar
Final blend
Type a volume for every lot.
Alcohol, TA and sugar are optional on each lot.
Up to 8 lots.
pH is not averaged. pH is logarithmic and each wine buffers it differently, so a blend’s pH is not the average of its lots. Make a small bench blend in the same proportions and measure it.
Mixing two liquids to hit a target? Use the Pearson square calculator.
How do we calculate this?
The exact formulas used in this tab:
What this calculator does
Works out what a blend of 2 to 8 lots comes out at: the total volume, each lot’s share, and the blend’s alcohol, titratable acidity (TA) and residual sugar.
- Each value is the average of the lots, weighted by their volumes.
- Alcohol, TA and sugar are optional on each lot, but a value only shows once every lot has it: an average of only some lots is not the blend’s figure. Until then the page names the lots that are missing it.
- pH is not averaged, because it doesn’t blend that way.
The formula
Total volume V = V1 + V2 + … + VnShare of lot i = Vi ÷ VBlend value = Σ (Vi × xi) ÷ Σ Vi (x = alcohol % vol, TA g/L or sugar g/L)Each value shows once every lot has it: a partial average is not the blend’s figurepH is not averaged: it is logarithmic, so bench-test the blend and measure itSource: volume-weighted mass balance, as in the Pearson square (BYO, "Blending for Better Wines")
Worked example
Three lots, one without sugar
- Lot 1: 600 L, 14 % vol, TA 5.5 g/L, sugar 2 g/L
- Lot 2: 300 L, 12.5 % vol, TA 6.4 g/L, sugar 4 g/L
- Lot 3: 100 L, 13 % vol, TA 7 g/L, no sugar reading
- Total volume 600 + 300 + 100 = 1,000 L
- Each lot’s share 600 : 300 : 100 = 60% : 30% : 10%
- Alcohol 0.6 × 14 + 0.3 × 12.5 + 0.1 × 13 = 13.45 % vol
- TA, the same way 0.6 × 5.5 + 0.3 × 6.4 + 0.1 × 7 = 5.92 g/L
1,000 L at 13.45 % vol, TA 5.92 g/L
Sugar shows a dash and names lot 3: an average of the other two lots would leave out a tenth of the wine.
Sugar typed for lot 3
- The same three lots: 60%, 30%, 10%
- Sugar: 2 g/L, 4 g/L, 3 g/L
- Residual sugar 0.6 × 2 + 0.3 × 4 + 0.1 × 3 = 2.7 g/L
The blend has 2.7 g/L of sugar
Questions
Why can’t I average pH?
pH is a logarithmic scale: one pH unit is a tenfold change in hydrogen-ion concentration. And each wine resists change differently (its buffer capacity), so a blend’s pH can land anywhere between the lots. Make a small bench blend in the same proportions — say 60 mL, 30 mL and 10 mL — and measure its pH.
What if a lot has no reading?
Leave it blank, and the others still show. That value shows a dash, with a note naming the lots that are missing it, until you type it for every lot. An average of only the lots that have it would quietly leave part of the wine out, and could be far off the real blend.
How is this different from the Pearson square?
They use the same arithmetic in opposite directions. This calculator starts from the volumes and tells you where the blend lands. The Pearson square starts from a target and tells you how much of two liquids to mix to hit it.
Will the blend measure exactly this?
Close. Alcohol, TA and sugar per liter mix in proportion to volume, so the figures are a good estimate. But tartrate can drop out after blending, and lab methods have their own spread, so measure the finished blend before you label or bottle it.