To Butter or Not to Butter...

One notable byproduct of malolactic bacteria (other than lactic acid!) is diacetyl, a compound that imparts buttery or popcorn-like aromas. While some aim to promote this character in their wines, others may prefer to minimize it. Read on to learn more about winemaking decisions that influence diacetyl production.

Tips for Managing Diacetyl

Strain Selection

Some ML strains like PN4™and BETA™ produce more diacetyl, while strains like VP41™, O-MEGA™, and ML PRIME™ produce less.

Inoculation Timing

Co-inoculation of yeast and bacteria minimizes diacetyl, since yeast consumes it as bacteria produce it.

Lees Contact

Yeast and bacteria in the lees aren't necessarily dead; they can remain alive for months. Lees contact allows for the consumption of diacetyl, decreasing the total amount in the wine.

SO₂ Management

Adding SOâ‚‚ just after MLF protects diacetyl. SOâ‚‚ binds to diacetyl in a reversible reaction. Initially, the diacetyl level will seem to disappear, but over time, the reaction will reverse and the diacetyl will be released. 

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