MLF Restarted After K-Meta?

[jstan]

Hi,
I started a MM Ren Pinot Noir kit 6 months ago (June 3rd to be exact). It fermented completely to a SG of .990 in a bit over two-weeks. At that point I took a taste and felt that the wine would be too tart and acidic for my liking and decided to experiment with MLF. So I left the wine on the gross lees, added MLF nutrient and inoculated with Wyeast liquid malolactic culture. The MLF seemed to take hold nicely, but after another two-weeks I started getting some rotten eggs smells. I immediately racked off the lees twice, both times running the wine through a copper scrubbing pad and splashing to introduce oxygen. While this took care of the volatile sulfur compounds, I was concerned about that the aggressive racking/splashing leading to oxidation and decided to trade the MLF for the safety of SO2 and added 5g of K-Meta. At that point I basically assumed MLF was over, never to happen again.

The wine's been bulk aging, more or less untouched since then (I did add some oak cubes, tannin, and sur-lie, but no further k-meta or racking) and I haven't really been watching it too carefully.

Well, last night I ran a free SO2 test on another batch that was ready to bottle (a WinExpert French Cab) and decided to test the SO2 in that Pinot Noir as well. Turns out the free SO2 in the Pinot is down to 8ppm. Interestingly, I got lazy, left the carboy in my dinning room and, to my surprise, I noticed a bubble pop through the airlock while eating breakfast. I've had my eye on the carboy all day and it has continued to bubble slowly all day (maybe one bubble every 5-10 minutes). The wine seems fully de-gassed and I don't think this is due to temp increase since my dinning room is the coldest room in my apartment.

So, now I'm wondering if the free-SO2 has declined enough over the past 5 months for the MLF to have restarted?! Any thoughts? (and, no, I don't have a chromatography kit )

Thanks!

 

[grapeman]

8 ppm is not enough to prevent mlb from working so it could be that. If it is, you should notice a small ring of tiny bubbles around the outside of the neck of the carboy at the top of the wine. Two weeks likely was not enough to finish a mlf, so it may have begun again. I would keep it warm and see if it will stop bubbling in another week or two. It won't spoil, especially if off any lees now. Let it finish and resulfite it and then bottle it before all the S02 is gone again.

 

[jstan]

Thanks. I don't see the ring of tiny bubbles at the top of the wine—I'm not sure if that always exists during MLF or not. Is there any possible explanation for the movement in the airlock other than MLF?

 

[ibglowin]

First, why did you do an MLF on a KIT wine?

Kits should never go though MLF as they have already been acid balanced.

The tiny bubbling ring is evidence that MLF is underway besides tiny little pin prick bubbles coming up the sides of the carboy.

How did you determine that a very young, very green wine would be too tart or too acidic to your liking?

How are you determining SO2 levels?

How did you degas?

 

[jstan]

Hi Mike,
I spoke with George at FVW before attempting MLF and he said that, while he doesn't typically recommend MLF on kits, that it is okay to try MLF on MM kits—but that is the only brand that he thinks will work with MLF (it has to do with the type of acids kit manufacturers use to adjust acidity).

This was my fourth kit. And while I'm obviously not very experienced, I could tell that it was very acidic—and after six-months of aging and a couple weeks of MLF I still think this is the case, so I think my judgement was right about that.

I used an Aeration-Oxidation kit to test SO2. All of the reagents were fresh.

I haven't deliberately degassed, but the wine's been racked a couple of times, stirred regularly, and has been bulk aging for 6 months now. That aside, I made the mistake of not fully degassing my first kit, so I have an idea of the sensation that an incompletely degassed wine has in the mouth, and this wine seems degassed to me. I'm sure it still has some CO2 in it, but I don't think that it's a substantial amount and it would seem strage to me if a seemingly flat wine just spontaneously started degassing after 6 months. Does that actually happen?

Thanks!

 

[Pumpkinman]

Wow.....

It is strongly recommended against putting a kit through MLF, at first I thought that it was because most kits contain sorbate and adding it is part of making a kit, but if this were the case, you could leave out the sorbate and ad MB.
Tim Vandegrift - Technical Services Manager for Winexpert stated the following on another forum:

Sorbate is not added to kits at packaging. However, there exists the possibility that some sorbate is in the juices, from raw materials, so it's strongly contraindicated.

It's extremely difficult to induce MLF, and the results are nasty.

Although you will hear of a few people that have successfully put a kit through MLF, not many have.

A young wine will be acidic, I'm guilty of the same mistake, you have to have patience, and test/taste every few weeks.
I would have splash racked a few times before ever using copper, that is always a last resort.

Don't be discouraged, if MLF has restarted, get that carboy warm, even if you put a heat pad under or around it, at 73°, MLF will cook along fast.
You need to get a Chromatography test kit, this is a surefire way to tell if MLF is complete. Midwest supply and Presque Isle Wine Cellars usually always have them in stock, I think a few buy their supplies through Presque Isle Wine Cellars.

Degassing by hand isn't easy, I've tried multiple times and it seems like I did nothing, I'm waiting on my All In One Pump, that'll take care of that problem!

Tom

 

[ibglowin]

Just curious if this was one of the frozen pails that Mosti sells? If so those are pretty much a fresh juice product. If this is a regular Mosti Renaissance kit then I am still surprised George would recommend MLF but I will have to defer to him as I am sure he has toured the facility as of late and knows their process better than we would.

I don't think 2 weeks is enough for an MLF to completely finish. The only way to tell is by doing the chromatography test. I have 8 carboys from fresh grapes that I started MLF on over a month ago now and I have several that are still showing signs of MLF (bubbling ring plus tiny bubbles coming up) and I have had them on heating pads the whole time to keep them ~68 degrees.

If you added Tannin that is going to make this wine taste tart and also make it take longer to mature. It should not be used if your in a hurry to drink your wine. 6 months is still a pretty young wine especially with the Tannin addition.

I think you will have to be patient on this one and give it another 6 months to let it settle down some more.

Whatever you do, never add any Sorbate to this kit or any wine that has had MLB introduced to it or your going to have a real mess on your hands.

 

[jstan]

Lot's of stuff here! First, I want to emphasize that this batch is an experiment. I understand that and I understand that I may end up gallons of undrinkable swill. I also know that whether this batch is good, bad or totally undrinkable, I've learned a lot in the process and that education is worth the money I've spent. I'm hoping to move away from kits and start working with frozen grapes, so I've been trying to deviate from kit instructions to see what I can learn. That said, on to specific comments/questions...

No, it wasn't a frozen pail, it was a Renaissance kit. And I should clarify that George didn't recommend MLF, but said that it could be done on an MM kit (I believe his explanation was that MM uses only tartaric acid to adjust acidity, rather than the malic acid containing blends used by other kit makers, so MLF would not too dramatically cut the acidity and make the wine flabby). He also gave me the usual warning about unpredictable results when deviating from kit directions.

I also understand the Sorbate issue, but thanks for the reminder.

Both the copper and the tannin additions were based on bench trials. In the case of the volatile sulfurs, I pulled two samples of wine: one sample I poured back and fourth between two glasses to aerate and the other I poured between two glasses that contained a ball of copper wire. The improvement with the copper was much more pronounced than without it, so I went with the copper. For the tannin addition, I drew 16 samples and added to each a different combination of 4 levels (no addition, slight addition, moderate addition, strong addition) of 2 different tannins (tannin riche extra & tannin complex). After 2 weeks my wife and I tasted the samples (blinded) and both agreed that one sample was much better than the others—it corresponded to an addition of 1.5g tannin riche extra and 1.0g of tannin complex. So I understand the effect of the tannin addition on the wine.

While I really appreciate all of the input, my question was simply about why I'm seeing movement in the airlock at this point. I'm 99% sure that the alcoholic fermentation completed to dryness months ago and I don't see how it could be the result of temperature changes causing expansion or spontaneous degassing (though I don't know about spontaneous degassing and wonder if that ever happens). The only explanation that I see is that free-SO2 fell low enough for the interrupted MLF to restart. That said, I don't see the ring of tiny bubbles that is typically indicative of MLF (though I did have this when I started MLF the first time). I did put a heating pad on the carboy last night and have warmed it up to 72 F to help the MLF along, assuming that's what's going on. Again, my question was (and still is) if this sounds like MLF started up again or if you all see some other possible explanation. I'm not in a rush to bottle, so I'll happily wait and let it finish, I just want to understand what is going on in my wine. Thanks again.

 

[ibglowin]

Just my $0.02 here but its either:

degassing whatever CO2 is left

or

MLF has restarted.

Its hard to believe that you would see an airlock move without seeing a big bubble ring as well as a whole lot of tiny pin pirck bubbles moving up the side.


One of my carboys of fresh grapes that I added MLB over a month ago just last week decided it was time to take off and Its rocking along like crazy when the heating pad is on. It slows down considerably but is still quite evident at night when It has cooled off all day long.

If its MLF you should see some sign of it even if its just a tiny ring of bubbles.

 

[grapeman]

I would keep the temp to about 72 for a few days and see if the ring of bubbles forms along with the tiny rising bubbles. If it does, it is likely mlf and I would just let it finish up for good. I don't see any real problem, like you say, just a curiosity why it is doing it now. Like I said, probably the S02 just got low enough for it to work at a slow pace. Warm it up and speed that process along.

 

[jstan]

Thanks everyone. I've noticed a few tiny bubbles have formed along the edges of the surface of the wine today. It's nowhere near a full ring (it's literally a few bubbles), but it maybe an indication that MLF is indeed picking up...or I may be starting at my wine too much . I'll keep it warm and see what happens.

 

[tingo]

Pumpkin man you wrote "at first i thought it was because of sorbate" as your reasoning for not putting a kit through mlf but then followed it by "but". Now, i have never made wine from a kit before, im a fresh grape kind of man. But for my own curiosity whats the reason for no mlf in kit wine? The only thing that comes to mind is if it contains acid blend which would include citric acid? But other than that and sorbate im stumped.

 

[ibglowin]

Kit wines come acid balanced. They also have higher proportions of Malic acid than normal. Performing a MLF on a kit wine is not only unnecessary but you could end up with a very flabby unbalanced wine with a high pH and suspect to a lot more problems if you do.

 

[jstan]

Tingo, my understanding is that it is, like you said, the acid blends that most companies use in their kits. One, the citric acid can be converted to acetic acid and, two, the conversion of the malic acid in the blend to lactic acid can lead to a big drop in acidity (& increase in pH), leaving the wine flabby and possibly insufficiently acidic for safe aging. Anyone know of any other potential problems?

 

[ibglowin]

Other than the package of Sorbate they throw in each kit......

 

[Pumpkinman]

Tingo, I haven't made kits either, but apparently to stabilize the kits, acids are added, including malic acid, if you put a kit through MLF it would become very flat, not to mention the sorbate issue.

 

[tingo]

Hmmmmm..... Why would they adjust acid with malic? Seems appropriate for maybe a fruit wine like strawberry but for grapes? Seems odd. Now im really curious. As we all know malic acid is unstable and less acidic than tartaric. Maybe cost then? Or the risk of tartrate precipitation during shipping?

 

[Pumpkinman]

Tingo, I don't have an answer for you, each company stabilizes and balances their kits as see fit.

 

[ibglowin]

Who said they adjust with Malic?

The process of going from fresh grape juice to a juice concentrate in shipping box that can sit on a shelf for a couple of years (stable) with 2-3 gallons of water removed, flash pasteurization on top of that could very well mess up the natural acid balance leaving one over the other.

Hmmmmm..... Why would they adjust acid with malic?

 

[ibglowin]

The best explanation as to why you should never attempt MLF on a kit wine comes from Daniel Pambianchi's book "Techniques in Home Winemaking".

Do NOT attempt MLF on kit wines because these types of juices have been tartrate-stabilzed during their production and thus contain a very high proportion of malic acid, which would be converted to lactic acid. The resulting wine would have very little acid, and a high pH making it very susceptible to bacterial infections....