Chapter 10

Tartrate Stabilization of Wine

(book excerpts)

After fermentation, but prior to bottling, tartrate stabilization is conducted to prevent the precipitation of potassium bitartrate (KHT) and (less commonly) calcium tartrate (CaT) from precipitating out of the wine when stored and/or chilled post-bottling. Precipitation occurs due to the instability of tartaric acid in its bitartrate salt form, which is known as potassium hydrogen tartrate as a supersaturated solution. Potassium bitartrate is commonly referred to as cream-de-tartar or wine diamonds, and generally, these deposits do not meet with consumer acceptance. Consumers often confuse these harmless crystals with glass fragments. In general, it is more common for white wines than red wines to undergo cold stabilization for the following reasons: (1) white wines are bottled earlier than red wines so potassium bitartrate crystals have less time for precipitation; (2) consumers commonly store white wines at colder temperatures, which increases the risk for bottle precipitation; and (3) crystals are typically more noticeable in white wines than in red wines. Thus, winemakers strive to reduce the potential for bottle precipitation. A wine may be defined as cold stable if it does not throw a haze or sediment of crystals after exposure to cold, but there is little agreement on any uniform time/temperature parameters. Many quality winemakers around the world refuse to alter a perfectly good wine (and possible strip away flavors) just to make it more presentable.

Click on the following topics for more information on tartrate stabilization of wine.

Topics Within This Chapter:

  • Tartrate Instability in Wine
  • Potassium Bitartrate
  • Calcium Tartrates
  • Testing Wine Calcium Tartrate Stability
  • Methods of Tartrate Stabilization of Wine
  • Stabilization by Chillproofing
  • Stabilization by Contact Seeding
  • Agitation, Temperature, and Filtration
  • Stabilization by Electrodialysis
  • Sensory Effects
  • Inhibition Techniques by Product Addition
  • Metatartaric Acid
  • Mannoproteins
  • Carboxymethyl Cellulose
  • Potassium Polyaspartic Acid
  • Wine Suitability with Crystallization Inhibitors
  • Measurement of Cold Stability of Wine
  • Three-Day Freeze Test
  • Freeze/Thaw Test
  • Modified Mini Contact (UC Davis) Conductivity Test
  • Potassium Concentration Product Test