Vintage 2020:MLF for our Cabernet Sauvignon and Cabernet Franc

On Thursday, November 26, 2020, I blogged about Vintage 2020: Racking Our Reds After Fermentation. The next step after racking is to inoculate the wine with malolactic acid bacteria to enable converting of the malic acid to lactic acid. We did this step on November 24, 2020 using VP41 as our choice of MLF bacteria.
We chose VP41 because it is an Oenococcus oeni known for its tolerance to high alcohol and low pH conditions. But it has many other qualities that make it a very good choice for malolactic fermentation such as:¹

• pH tolerance > 3.1
• Alcohol tolerance: up to 16% volume
• SO₂ tolerance: up to 60 mg/L total SO₂
• T° tolerance > 16°C
• Low nutrition demand
• Good implantation
• MLF Kinetic: Fast
• Low volatile acidity production
• Bacteria cinnamyl esterase negative: cannot produce precursors for ethylphenol production by Brettanomyces
• No production of biogenic amines
• Co-inoculation recommended

When we went to Jonathan Edwards Winery to inoculate our 2020 Cabernet Sauvignon and Cabernet Franc, we retrieved samples of those wines as well as our 2019 Cabernet Sauvignon and Cabernet Franc to do a comparison. We also tested the 2019 and 2020 samples for the pH and titratable acids:

Sample	pH	TA
2019 Cabernet Franc	3.57	8.5 g/L
2019 Cabernet Sauvignon	3.57	7.0 g/L
2020 Cabernet Franc	3.22	8.5 g/L
2020 Cabernt Sauvignon	3.27	7.5 g/L

Here are the results of the paper chromatography that my husband ran on those samples:

After running the paper chromatography, we had to wait approximately 24 hours for the spots to develop but when it did, we were pleasantly surprised. The paper chromatography revealed that for the 2019 wines, all of the malic acid had been converted to lactic acid. In comparison, the 2020 wines had not yet been inoculated so having malic acid preent is not a surprise.

Our next step is to do the paper chromatography on the MLF completed 2020 Cabernet Sauvignon and Cabernet Franc.
References:
1. Lalvin VP41.