Have you heard of malolactic fermentation before? It sounds like something out of a science class rather than something you’d find in your wine, right? But you might have heard this term thrown around at wine tastings or in wine tasting notes. Have you wondered what it means? Or maybe you’ve heard it referred to as ‘Malo’. I know my partner thinks he’s pretty cool when he describes a wine as having this (and I humour him occasionally). So what is malolactic fermentation in wine? This wine guide will cover the basics of malolactic fermentation so you know what it is, what flavours it creates and where you’ll find it. So next time someone describes it you know what they’re talking about!
What is malolactic fermentation in wine?
Malolactic fermentation, mal, MLF – you may have heard some of these terms used. But what is it? Well, this process is where malic acid converts to lactic acid. This isn’t technically a fermentation as it is the result of bacteria (not a gross one a good one) rather than yeast, but it is an essential process in wine. Sounds yuck, but it’s very important!
Malic acid is a tart acid that you find in green apples. On the other hand, lactic acid is more creamy and is the acid found in milk, cheese and yogurt. So you can start imagining what this might do to the taste of a wine as this process takes place.
What does malolactic fermentation do to wine?
So what does this process do to your wine? Malolactic fermentation in wine softens the taste and texture of wine, adds complexity and character, and makes sure the wine is stable before bottling.
Malolactic fermentation reduces acidity as the malic acid changes. This leads to wines with a creamy, more velvety texture than wines that don’t go through malolactic fermentation. This can be so important to the taste and style of a wine as before this process it might be too harsh and astringent on the palate. This process makes the wine softer and more approachable.
Malolactic fermentation is also thought to generally enhance the body and flavour of wine, and some believe it causes better integration of fruit and oak character when this process takes place in the barrel.
Want a good example of malolactic fermentation? Think oaked Chardonnay. Those creamy and buttery notes with the velvety texture are in part due to the influence of malolactic fermentation.
Where will you find it?
Although you may not believe it, nearly all red wines and some white wines undergo malolactic fermentation. Usually, full-bodied dry whites and medium to full-bodied dry reds experience the most benefit from the process.
Not all wines benefit from it, however. Many whites, especially those that are lighter and fruit-driven need acidity, and so winemakers don’t want malolactic fermentation to take place. They can stop this process by maintaining low temperatures and keeping low levels of sulphur dioxide, as well as not placing the wine in barrels. Good examples of these are Riesling and Sauvignon Blanc.
Although red wines more commonly benefit from malolactic fermentation than whites to accentuate fruity characters and remove some acidity, there are some exceptions: Chardonnay being one, and Viognier being another. You’ll also see the difference in flavours – take an unoaked Chardonnay versus an oaked Chardonnay as a prime example. Also, warmer climate reds may not have enough acidity and so won’t benefit from having this further removed.
A good indicator is looking for oak influence in these wines as this usually indicates some form of malolactic fermentation has taken place. Another clue is a creamier, oily texture in the wine and more rounded acid. If you find this on the palate, you’re likely trying wine with malolactic fermentation.
In summary: Malolactic fermentation in wine
Whether you like buttery Chardonnay or not, malolactic fermentation in wine is actually a very important process that you’ll find is behind many of the wines we drink. Not only does it add flavour, but it also helps the wine get to us in the bottle, and makes sure it is nicely balanced.
So next time you’re drinking a wine that you’re enjoying for its fine balance of acidity, you know to thank malo!