When to give up on an MLF?

[baron4406]

Ok with my Chilean grapes/juice this year I tried to make a Bordeaux style blend. 6 gallon buckets of Cab Sav, Cab Franc, and Merlot. Plus one flat of grapes of each varietal. All of it in my 25 gallon fermenter. I've never tried an MLF and I decided this batch would be the one I'd try it with. So the primary went quick, after two weeks I pressed and I got about 20 gallons in 4 carboys. Three of the carboys I decided to try the MLF and one of them was a control. Took the advice of the winemaker at my LHBS, added some oak chips, made sure my PH was in the low 3's, and warmed up the carboys(they are at about 75 degrees). Added some Wyeast MLF culture and off we went........stirred the carboys everyday. After two weeks-nothing. Ironically the "control" without the MLF shows a little activity but not these guys. I know MLF isn't dramatic, you should just see small bubbles. Well I've seen nothing, the wine is as calm as can be. I usually rack again in a week or two then hit long term storage so I'm wondering if I should just sulfite these batches and give up.
Ironically, the wine tasted fantastic when it came out of the primary. Usually grape wines are harsh at this point

 

[NorCal]

Did you SO2 after primary? I'd get the mlf paper kit and test the wine to really understand what is going on.

 

[baron4406]

No didn't SO2 after primary

 

[Johnd]

Frequently, there are no outward signs of MLF, and it can take months to complete, you're in a marathon, not a sprint. Personally, I shoot for higher pH than "low 3's", more like 3.4+. My chileans last year didn't complete after over 4 months, that's when I sulfited and moved on. I believe that the sulfite in the grape transport process increase the difficulty, but have no proof, just a theory.

Get a chromotography test set, or malic strips, then you can have empirical evidence of progress or lack thereof. It's a lot more sure than just looking for action.

 

[Ajmassa]

I've got 2 successful MLF's under my belt now (simultaneous) and neither had visible activity. I used paper chromatography kit to test and completed in Less than a month.
Maybe your Bordeaux tastes less harsh because your harsher malic acid is succesfully converting to lactic.
I dig the Bordeaux blend idea and have that on my to-do list. I'll be doing a similar blend in fall but I'm not sure when I'd blend. It sounds like fermenting everything together worked well for you.

 

[baron4406]

Yea good points guys. I'm just worried about leaving this wine sit so long without SO2

 

[stickman]

As others have said, sometimes there are no signs of activity. One thing you can try, stop stirring for a week or two, then use a flashlight to view the wine at the neck of the carboy. By not stirring you give the wine a chance to become completely saturated with co2, if the MLF is going slow, some small bubbles might be visible at that point. I have never tried it, but I've been told by an experienced winemaker that a jewelers loupe is sometimes needed to see the bubbles during a slow ML.

 

[skeenatron]

Yeah the advice about checking the actual malic acid level is pretty key. Also your wine conditions may just be the issue. Too low of a pH and too low of a temperature will do it. I've had more issues with MLF over the years than any other aspect in winemaking. Getting your wine in an acceptable ph/temp range for your specific bacteria strain can be a pain. I use a very resilient strain of Chris Hansen CH16 bacteria and most of the time I can't get the reds to finish MLF without getting the actual wine temp itself to around 65-70F.