Malo lactic Fermentation

Malo-lactic fermentation – we have all heard about it and we know that it affects the taste of the wine. Read on to discover what exactly it is and how it works.

What is malo-lactic fermentation?

1. Malo-lactic fermentation occurs after the end of the primary fermentation. Winemakers then introduce strains of malolactic bacteria that cause the resulting fermentation.
2. These bacteria convert malic acid - naturally present in fruits like grapes and apples - to lactic acid, which reduces the acidity of the wine and improves its flavor.
3. What exactly happens is that the malolactic bacteria convert the excess malic acids in red and some white wines into lactic acid. Lactic acid is less acidic and makes the wine taste better.
4. Wines that come from regions that are colder tend to have higher levels of malic acid and generally require malo-lactic fermentation to make them milder.
5. Seasoned winemakers can use malo-lactic fermentation to impart complexities of flavor and aroma to wines.

Tips on malo-lactic fermentation

1. Winemakers generally wait until the end of primary fermentation before adding the malolactic bacteria culture. Ongoing fermentation will be visible in the form of tiny carbon-dioxide bubbles. When the bubbles stop, the fermentation will be complete.
2. The time required for malo-lactic fermentation can vary depending upon the temperatures. Warmer temperatures work best and winemakers generally prefer to introduce the malolactic bacteria in the summer months.
3. Malo-lactic fermentation is generally used for dry red wines and sometimes with select dry white wines though it is not recommended for sweeter wines.
4. It is also generally used for high quality wines that are made from grapes.
5. Malo-lactic fermentation tends to emphasize fermentation aromas and flavours and reduces the fresh fruity flavours of wines
6. Malolactic bacteria are not very alcohol tolerant and for malo-lactic fermentation to be successful, the wine must have an alcohol level below 14%.

Caution

Always make sure that all the malic acid has been converted. You can buy easy to use kits for testing the wine to ensure that the conversion is complete.