Chardonnay has a reputation for being buttery.

Which is rather unfair to the grape. It had nothing to do with it.

The usual suspects are bacteria.

After fermentation, they can turn sharp malic acid (think green apple) into softer lactic acid (think milk). The wine becomes rounder, less tart, a little more comfortable in its own skin.

This is malolactic conversion.

Occasionally, the bacteria also leave behind diacetyl, the compound responsible for that unmistakable buttery aroma.

A little can be rather lovely. Too much, and you’re drinking the sort of Chardonnay served lukewarm at a gallery opening. The art deserves better. So does the wine.

But here’s the interesting part: it’s a choice.

Winemakers can encourage or prevent the process. Some want a Chardonnay with freshness and bite. Others prefer something softer and richer. And malolactic conversion doesn’t always produce a buttery wine.

So Chardonnay isn’t naturally buttery.

It’s just occasionally been encouraged to behave that way.

The grape would like its reputation back.

OINOS — Wine, in context.