🍷 Malolactic fermentation
Bacteria turn sharp malic acid into soft lactic acid.
Malolactic fermentation, or "malo", is a second fermentation of wine that is done not by yeast but by bacteria. They turn sharp malic acid into soft lactic acid. The wine becomes softer and rounder.
The work is done by wine lactic acid bacteria, most often the species Oenococcus oeni. They usually act after the main alcoholic fermentation, either on their own or after the winemaker adds a bacterial culture. Malolactic fermentation takes place in most red wines and in some whites, such as Chardonnay.
As a by-product the bacteria create diacetyl, one of the main aroma compounds of this fermentation. It gives a buttery smell. After malolactic fermentation a wine may have more histamine.
Lactic acid bacteria also work in dairy products: they ferment yogurt and kefir, and diacetyl forms in fermented milk products as well. This is why wine can have similar creamy notes.
How it connects to Wine
🍷 Malolactic fermentation ← similar ← 🍷 Histamine in wine ← affects ← 🍷 Wine
Links
- Next step
- 🍷 Malic acid
- Works with
- 🧫 Lactic acid bacteria
- Who works with it
- 🍷 Oenococcus oeni, 🍷 Diacetyl, 🧪 Lactic acid
- Part of
- 🍷 Fermentation
- Similar and different
- 🍷 Deacidification, 🍷 Histamine in wine
- Wine and milk
- 🧫 Lactic acid bacteria, 🥣 Yogurt, 🥛 Kefir, 🥣 Sour cream, 🔄 Fermentation
Frequently asked questions
What is malolactic fermentation?
It is a fermentation in which bacteria turn malic acid into lactic acid. The wine becomes softer.
How is it different from alcoholic fermentation?
Alcoholic fermentation is done by yeast, which turns sugar into alcohol. Malolactic fermentation is done by bacteria, which change the acid.
Why is Chardonnay sometimes creamy?
Because of malolactic fermentation: it creates diacetyl, which gives a buttery smell.
What to read next
- 🔄 Fermentation — Lactic acid bacteria turn lactose into acid and the milk thickens.
- 🥣 Yogurt — Fermented with Lactobacillus bulgaricus and Streptococcus thermophilus.
- 🍷 Histamine in wine — A substance that gives sensitive people headaches and a flushed face.
- 🥛 Kefir — Fermented milk drink made with kefir grains, where bacteria and yeasts live together; under the Codex, at least 0.6% lactic acid.
- 🥣 Sour cream — Soured cream.
Similar
🍷 Lees · 🍷 Lees ageing · 🍷 Alcoholic fermentation · 🍷 Acidification · 🧪 Wine adjustment and stabilisation
What it includes
Sources
- Wikidata Q654005
- Smit A.Y., du Toit W.J., du Toit M. Biogenic amines in wine: understanding the headache. S Afr J Enol Vitic 2008;29(2):109–127
- Nielsen J.C., Richelieu M. Control of flavor development in wine during and after malolactic fermentation by Oenococcus oeni. Appl Environ Microbiol 1999;65(2):740–745
- Sereni A. et al. Impact of the timing and temperature of malolactic fermentation on the aroma composition and mouthfeel properties of Chardonnay wine. Foods 2020;9(6):802
- Codex Alimentarius: Standard for Fermented Milks (CXS 243-2003)