877.812.1137

“How do I know if my Malolactic Fermentation is complete?”

One of the biggest questions we get from winemakers in the wintertime is:
“How do I know if my Malolactic Fermentation is complete?”

There are several ways to check if MLF (aka Malo) has finished in your wines. Here’s your guide to cracking the case:


The Paper Chromatography Mystery

What’s happening: You’re playing chemist, spotting malic acid on the paper like a pro.
How to do it:

  • Grab a chromatography kit (your detective tools).
  • Drop a little wine onto special paper, alongside controls for malic, lactic, and tartaric acids.
  • Let the solvent (your magical reveal potion) do its thing for 24 hours.
    Look for clues: If the malic acid spot has vanished, your wine’s MLF journey is complete!
    Why it’s fun: It’s like wine CSI! Who doesn’t love some science with their sip?

The pH & TA Detective Work

What’s happening: Malolactic fermentation is altering the wine’s balance.
How to do it:

  • Monitor the pH and titratable acidity (TA).
  • A slight rise in pH and a drop in TA could mean malolactic microbes are working their magic.
    Why it’s fun: You’re charting your wine’s story as it evolves—geeky, but deeply satisfying.

Side Note: This is a great tool to pair with the chromatography test or to help decide when to send your wine out for MLF testing. It’s always better to have a concrete answer that Malo has finished—otherwise, you could end up with bottles popping their corks come June!


Enzymatic Testing: The Smart Tech Sleuth

What’s happening: You’re going high-tech, directly measuring how much malic acid is left.
How to do it:

  • Use a malic acid test kit and follow the instructions. The test will tell you quantitatively how much malic acid is still hanging around.
    Why it’s fun: Precision tools make you feel like a winemaking scientist extraordinaire.
    Pro Tip: We highly recommend the Sentia Unit or Vinmetrica Units for these types of tests.

Lab Work: The Professional Investigator

What’s happening: You hand off the mystery to the experts.
How to do it:

  • Send a wine sample to a professional lab to get the full malic acid report.
  • MWG offers Malo Testing for just $10.00 per test!
    Why it’s fun: It’s like getting a report card for your wine—but hopefully, it’s all good news!

Taste Test: The Flavor Detective

What’s happening: Your palate is the tool here!
How to do it:

  • Taste your wine and pay attention to the acidity. If it’s gone from tart to creamy, your malic acid may have transformed into silky lactic goodness.
    Why it’s fun: You get to taste-test your wine a lot. It’s the tastiest part of winemaking!

Pro Tip: Cover Your Bases

Even if you’re convinced MLF is done, it’s a good idea to confirm with chromatography or a malic acid test. No one wants a surprise fermentation later!


Would you like help picking your detective method?
Call Musto Wine Grape at 877-812-1137 with any questions. And don’t forget to check out videos at www.WinemakingInstructions.com for more in-depth winemaking tips!

MORE Malo Articles to Explore:

A Guide to Malolactic Fermentation

Timing Your Malolactic Fermentation

What are Malo lactic bacteria and when do I add them?