Tartrate precipitation: a process, not a fault

The standard

A reached solubility limit determines when tartrate precipitates: only when temperature and alcohol drive the dissolved amount beyond what stays soluble do crystals form.

Criteria

  • The wine holds potassium bitartrate in supersaturated solution
  • Cold or rising alcohol lowers the solubility
  • Crystals form and settle as a deposit
  • The deposit is flavourless and sterile

Distinction

Tartrate precipitation ≠ tartrate stability: stability is the resistance to this very precipitation. Tartrate precipitation ≠ microbial turbidity: the crystals are sterile and flavourless. A reached solubility limit is thus a physical cause, not a sign of spoilage.