What is malo and lactic fermentation?

There are two different types of fermentation; malolactic and lactic fermentation.

To start with it’s better to explan what is malic acid. Most people will associate it with the tart acid you find in the likes of an apple like a granny smith. By contrast lactic acid is found in milk, butter, yogurt and cheese. You’ll find it as the ‘butteryness’ in the wine, more familiar for most in a Chardonnay.

Malolactic fermentation is a secondary fermentation that occurs in most reds and some whites where the harsh malic acid is converted to the softer lactic acid. For many reds and the selected whites, it takes place in the cooler climates whereas it occurs in whites where winemakers are looking for a particular style; some might say a style that is more approachable with less fruit concentration. Other winemakers may choose to put half the blend through malo and the other half normal fermentation so when blended together it produces a wine that both has the butteryness and roundness as well as the fruit concentration with that touch of ‘complexity.’

But it’s not just about adding ‘complexity’ to a wine. Adding lactic bateria to a wine after fermentation requires careful handling in the winery so the buttery or ‘diacetyl’ is not too overpowering. Malolactic fermentation has an affinity to some grapes more than others for example Chardonnay. Whereas a winemaker wouldn’t choose to put say a highly acidic Riesling through this secondary fermentation.

Everyone has their views and tastes on the types and styles of wines they like; neither is wrong but it’s important to at least be aware of and apprecaite the care and handling that goes into a bottle for us to consume with or without a meal.