Late Malolactic fermentation

[Wheelman]

I decided on this year's(2018) wine to add an ML bacteria. Note: I have never done this prior. I was told by a winemaking friend that all reds go thru MLF naturally and not to bother adding bacteria.

So I bought a chromatography test kit and ran some tests on the 2018 wines and all seems to be going well.

I still have a blend (Petite Syrah and Syrah) from last year's (2017) in a 3 gallon carboy. So I decided to test it. The test showed it still had Malic in it. In fact, I noticed a few bubbles when I blended it 2 weeks ago. It also popped the orange carboy cap a day after I blended it.
The PH is 3.45 SO2 is 8.
I have done a few SO2 additions and they always dissipate over time.

Is it possible, at this late stage, to add an ML bacteria? Should I bother? Why is there still bubbling at the top of the wine? There are few Lees because of racking, so if I do add ML bacteria should I add Opti Mali or similar?
Thanks in advance

 

[Dom Lausic]

That's a great question! I have red blend from last year that i am considering running through MLF, but not sure it is too late? At this point, i guess its a matter of taste? Also, i live in Toronto, so my cold cellar will start to get cold quickly over the next couple of weeks, which will really slow MLF down as temperatures drop. So that's another thing you would need to take into consideration. Especially if you're thinking of bottling soon. Also, the SO2 additions could affect the MLF if it's too high. Not sure how a ready of 8 would affect it......

But one thing I've learnt from this site, is that "there are no rules!" So, I don't imagine it could hurt...... But would also love to see others suggestions!

 

[cmason1957]

I am guessing that with both of the above wines, you have been doing regular SO2 additions. It might be worthwhile before spending the money on bacteria to determine the total SO2 level and the bound SO2. I have a theory that bound impacts success more than we know and is the cause many folks have reported problems in Chilean grapes.

 

[Wheelman]

I have been doing regular additions. I use the winemakermag.com sulphite calculator. This is from the website...
Assumptions
The calculator assumes that 57% of the sulfite actually becomes free SO2 to protect wine.

So does that mean I could assume 43% Is bound?
If I do get my wine tested what result levels would indicate it would be ok to add ML bacteria?
All I have ever tested was for free SO2. How do I test for total SO2?
Also of note, I have a vineyard from which these grapes were sourced

 

[Ajmassa]

With a free ppm level at 8 that’s a level should be tolerant for most mlb. But there no way to test for all the sulphites that have been bound over time. There’s also no spec’s on mlb’s bound So2 tolerences.

It’s one of those things that’s a possible cause when MLf struggles. But no way to tell. @cmason1957 - said it well. I’ve read it from multiple sources about total bound So2 as a factor. But like he said- to what extent isn’t detailed by anyone, but possibly more than we think.
Nothing to lose by adding it. Few bucks is all. In this scenario probably best to give it all the help your able with the rehydrating and nutrients and temp amongst others things. Then test in a few weeks and see if there’s progress.
No worry about lees. Even tho some of it can be malo food, stirring is mainly for lifting any bacteria that became buried back into the wine.

 

[Wheelman]

Thanks for the advice. I think I may give it a go.

 

[sour_grapes]

I have been doing regular additions. I use the winemakermag.com sulphite calculator. This is from the website...
Assumptions
The calculator assumes that 57% of the sulfite actually becomes free SO2 to protect wine.

So does that mean I could assume 43% Is bound?

Well, if that is how it is phrased, it is a misstatement. That 57% figure simply means that, of each K2S2O5 molecule, the resulting two SO2 molecules make up 57% of the weight (and the "unused" 2 K's and 1 O make up 43% of the weight). It is, in other words, not a very helpful figure.