November 4, 2014
MLF Chromatogram Oct 11, 2014
MLF Chromatogram Nov 4, 2014
Well, it’s been almost 3 months since I inoculated my VinoSuperiore wines for malolactic fermentation, or MLF.
A paper chromatography test on October 11, or 2 months after inoculation, showed that MLF in the 2011 Sangiovese and the tiny batch of 2011/13 topping wine were not quite complete, and that the 2013 was essentially complete.
MLF seemed to be going well and I expected that it would be complete within another week or two. So I didn’t worry as I got busy making new wine, including a Pinot Noir, and then spending a week touring the beautiful chateau wineries of Bordeaux.
But another test on November 4 shows not much more movement, and so, it would appear that we have a bit of a stuck MLF.
The spots on the 2014 Pinot Noir in the chromatograms illustrate the complete conversion of malic acid into lactic acid; and that’s how the Sangiovese should look like at the end of MLF.
And so the plan now would be to feed some lactic acid bacteria nutrients to the 2011 batch and 2011/13 topping wine to see if MLF can be completed. Organoleptically, the wine taste great at this point without any excess of acidity. The issue is that any residual malic acid, however small, is a potential source of microbiological instabilities or spoilage during aging or even in the bottle, so it needs to be dealt with.
As for the 2013 batch, it will receive a small dose of SO2 to stabilize it and it will then go into the cellar for aging. Once the 2011 completes MLF and is ready for the cellar, I will introduce some oak chips in both batches for added complexity.
Ah! A winemaker’s work is never done.
I’m not understanding what you call ML concentration. I assume you mean malic acid, but you say the Accuvin test gave you >1500 mg/dL – that’s pretty small. Did you really mean >1500 mg/L? Even that is small but still significant in wanting to reduce your high TA.
You also say SO2 is low – how low?
The first question you’ve got to ask yourself is if you really want an MLF to occur for stylistic reasons or only to reduce TA.
If you really want an MLF, you need to add a lactic acid bacteria culture WITH nutrients. Perhaps your culture was not fresh, not added properly, or it did not have sufficient nutrients … assuming your pH and temperature were good. You should not introduce any oxygen during MLF.
Otherwise, you can do a double-acid deacidification using SIHADEX. It’s always best to know the ratio of tartaric to malic acid to perform the process properly … I assume you don’t know this data. You can still give it a try but be very careful and follow instructions to the letter as you will be taking your wine to a very high pH.
Once deacidification (and MLF if successful) is complete and you have stabilized the wine with sulfite, cold stabilize the wine to precipitate tartrates and reduce tartaric acid.
The other alternative to minimize “playing” with TA is to backsweeten the wine. I know a lot of folks don’t like doing this because they think it makes the wine sweet. If you have high acidity, sugar will reduce the perception of acidity without making the wine taste sweet … assuming you don’t add too much.
Hope this helps.
Good luck.
Daniel
Sorry, about the units. On my MLFs, I followed the instructions to the letter and with nutrients. On the second I even started with apple juice, then did a 1:1 dilution with the wine. I certainly had an active culture at that point by notable CO2 production.
Free SO2 was <10PPM at the time, hence my discomfort and sense of being a bit "stuck" with this MLF and not wanting to spoil the whole lot waiting for Gogot (MLF).
Thanks for the info on SIHADEX, I'll research this and do a test lot if anything; and for the back sweetening recommendation.
Last, thanks for the great book; it has been invaluable.
Regards,
Brian
Daniel