What is malo? & Has it lost its halo?

I have vivid memories of the first varietally named Chardonnay I ever tasted. My boss in the 80s - the CEO of Natwest Finance - was a wine lover and purchased some Villa Maria Gisborne barrique-fermented Chardonnay for the Boardroom. It was big and bold and “fat”, the white wine equivalent of a wagyu steak. My initial tasting blew my socks off, I purchased a dozen to cellar but drank them all within a year.

This style of Chardonnay had three key winemaking features. First the grapes were well and truly ripe. Second, the wine was made and aged in oak barrels with a high proportion of new oak, giving a lot of oak flavour. Third the wines went through a full malolactic conversion, which gave an acidity not only lower, but softer and rounder in mouthfeel, not infrequently along with a noticeable buttery edge.

Since then, fashion has changed. When running wine tastings at a local cellar door I not infrequently find visitors who are reluctant to try the (very good!) Chardonnays on offer. When I probe the reason for their ardent membership of the ABC (Anything But Chardonnay) Club, it is usually an aversion to big oaky buttery styles of Chardonnay, which they assume to be the benchmark character of the variety.

While big oaky buttery Chardonnays are still around, winemaking has moved on from the fashion of the 80s and early 90s. Where oak is used, the proportion of new oak tends to be much less, usually less than 50% and often larger format oak is used as well. The grapes are sometimes being picked a little earlier, ensuring greater freshness and bite in the resulting wine.  The situation is, however, a little bit more complex regarding malolactic conversion and before we explore the various trends, let’s explain what it is.

 It was really only in the first half of the 20^th century that malolactic conversion (malo) was properly understood. Prior to that, it had long been noticed that when wines had finished fermenting, and were drained off into containers they would start bubbling and turn cloudy and this was once thought to be a kind of continuation of the alcoholic fermentation or a secondary fermentation. It is now understood as a process where lactic bacteria convert the malic acid in the wine (which comes from the grapes, the same tart angular acidity you perceive in biting into a crisp granny smith apple), to lactic acid and carbonic acid, the latter being given off as CO2 gas.

1g of malic acid => 0.67g of lactic acid and 0.33g of CO2

There are three results of this process. The first is a reduction of total acidity. The second is a change in the taste and mouthfeel of the acidity to something softer and a little creamier. The third is some reduction in fruity aromas, but in Chardonnay this is accompanied by a greater overall aromatic complexity.

Certain strains of lactic bacteria can also produce diacetyl which gives that buttery edge, this can be avoided by using other strains of lactic bacteria that don’t produce so much diacetyl. The timing of malolactic conversion also affects the production of diacetyl. Where it is initiated simultaneously with alcoholic fermentation, any diacetyl produced will be broken down by yeast and bacteria, but malolactic conversion initiated after completion of alcoholic fermentation contributes to higher levels of diacetyl. (Other factors such as the length and temperature of malolactic conversion and contact with lees also influence diacetyl levels). In short, buttery flavours are NOT an inevitable product of malo.

Malolactic conversion in red wines is generally considered desirable. In white wines however, it all depends on whether the expected wine should emphasize fruity aromas and fresh acidity or if the winemaker is looking for more roundness, body” and generosity on the palate.

 So now to answer, has malo lost its halo? Well, you might think so, if the only article you read about Chardonnay was the recent praise of Margaret River Chardonnay as the best in the world by Richard Hemming MW, writing for Jancis on 26 October 2023. He notes  “there is one notable winemaking trend in Margaret River Chardonnay: malolactic conversion is generally avoided, leaving the wines with a prominent acidic tang. This promotes particular freshness of fruit, although it can be mouth-puckeringly shrill in a few outlier cases.”

However, this Australian trend, not uncommon in other winemaking areas such as Victoria, when combined with early picking, has led Jancis herself to lament the frequent excessive austerity of some of these wines. In April 2023 she praised our Hawkes Bay Chardonnays as having “more depth and richness than many of the current wave of Australian Chardonnays, without austerity but with excellent natural acidity plus fruit flavour” and “malolactic conversion is a given”.

Meanwhile in Burgundy malo remains de rigeur. I often hear fruity, zestier styles of Chardonnay described as being more like Chablis because they have not gone through malo, but this is just wrong. Chablis typically undergoes a full malo which is necessary to soften the otherwise sharp acidity arising from the cool climate.  

Of course, malo does not have to be an all-or-nothing affair. Winemakers not infrequently put a portion of the wine through malo and leave a portion without to get the balance they are seeking of body and zest. But we can safely conclude that malo has most definitely not lost its halo. Rather, evolving winemaking sees greater sophistication in choice of clonal material, picking decisions, fermentation vessel and indeed, use of malo. The result is a greater diversity of style in increasingly excellent wines, especially in New Zealand, so that we can faithfully promise the most ardent ABC Club member, “there is a Chardonnay somewhere that you will love!”