Winemaking Calculator

Key assumptions & model notes

• Projected liquid volume drives the math. For must, projected liquid is approximated as f × must volume (typ. 0.60–0.80). For juice pails, f = 1. If you enter an override, it wins.
• Brix (°Bx) treated as sugar mass percent. Other solutes are ignored for this adjustment math.
• Dilution conserves sugar mass. Water-back uses Vwater = (Bi/Bf − 1) × f × Vinitial (density differences ignored; accurate enough for typical use).
• Acidulated water: When adding water, we assume it’s acidulated at your chosen g/L. The tool gives the exact grams for the water volume.
• Chaptalization is a rule of thumb. Sugar additions use selected factor g/L per +1 °Bx. Dissolve fully; retest Brix.
• pH response varies. We display three illustrative bands (Low/Medium/High response). Always bench trial when possible.
• Tartaric cap: Default max is 35 g per 5 gal pail (scaled by pails) to reduce sensory risk. You can change the cap.
• Water quality matters: Assumes chlorine-free, low-mineral water. Hard/chlorinated water can negatively affect wine.
• Potassium heuristic (context only, not a prediction): Higher K can drive pH rise during fermentation via tartrate precipitation dynamics. High K often means outcomes tend toward more buffering / lower apparent response and less predictability.
• How recommendations are chosen (important):
  • Conservative Start = the largest dose that stays above the target pH in the High Response worst case (and above style floor).
  • Balanced One-Shot = the largest dose that stays above the style floor in the High Response worst case (and within your max cap).
  • Bench plan (3 steps) = start with Conservative Start, then walk toward Balanced One-Shot with two follow-ups (retest each time).