Alcohol level too high for ML bacteria ... or will it just go slow ?

[chonn]

We picked fruit late and had some shriveling and long-story-short we have an ABV of 15.7.

Before we got these test results we pitched viniflora oenus as our ML bacteria which on the spec sheet is only tolerant to 14%.

We just tested and our ML level is 0.50 g/L which means the ML bacteria did something....since we probably started around 2g/L?

So will this ML fermentation complete, just slowly, or is it going to "stick" and I should dump in some CH16?

We turned the heat up a bit from around 68F to more like 74F....

 

[mainshipfred]

There was a thread a while back concerning ABV. The topic changed a little to the different methods used to calculate the ABV and the methods resulted in different numbers. There was never a definitive outcome so all the methods appeared to be logical. My point is perhaps your ABV could be a little lower or higher.

Also I believe the tolerances are probably higher then what is listed. The lower number is probably a safety to protect the manufacturer.

 

[chonn]

I don't mind the high ABV....we had a sense that was what we were doing when we chose the harvest date.

I just don't want to sit on lees for another month waiting for an ML to finish if it's not going to.

 

[winemaker81]

What method did you use to calculate the ABV?

The method I've used for decades ( [OG-FG] / 7.36 ) produces a result that is at least 0.5% above the other methods I looked at. For that reason, I don't trust it. If you're using that method, then your ABV is likely lower than you believe.

Beyond that, I agree with Fred. Published tolerances are those produced in a laboratory AND are intended to protect the vendor. The SO2 tolerance and ABV tolerance are probably higher than the values published.

If the malic acid level is dropping, the bacteria is doing its thing. If you consider the rate too slow or not working, then inoculating with another may be a good choice. Given the cost of MLB I'd give it more time if it appears its working, but that's your call.

 

[mainshipfred]

I don't mind the high ABV....we had a sense that was what we were doing when we chose the harvest date.

I just don't want to sit on lees for another month waiting for an ML to finish if it's not going to.

I just assume you did the initial racking off the gross lees. Do you feel a second racking is necessary at this time? Also, what is your experience with the time for MLF to complete? Mine always take at least 2 months and sometimes closer to 3. My bacteria of choice is MBL 31.

 

[Rice_Guy]

Wine is a multiple variable preservation system. ie there are enough variables that we can’t say a + b = c, Did the manufacturer factor in starting population or your actual SO2 or your nutrition level or the temperature etc etc. One factor will reduce the effect of or increase the effect of another variable. ,,,, The normal way to write about kill is one condition generates the lethal treatment for 50% or 90% or 99.99%.