WineXpert Spontaneous MLF in bottle

[SandbaggerOne]

Hello all,

I just opened a bottle of WineXpert LE 2012 Nebbiolo that I bottled in mid-November. It has developed a spontaneous MLF in the bottle. I can tell due to the development of some butterscotch flavors, reduction in acidity, and slight carbonation. I think this may be due to the use of a commercial Barolo that went through MLF to top off the wine, a risk I had not considered. I did not sorbate the wine but I did sulfite to 50ppm free SO2 at bottling. Does anyone have a suggestion? It does not appear that all bottles are affected as I can see a slight swirly sediment and evidence of carbonation in some but not others. Should I decant the wine into a carboy and let it finish MLF and then adjust TA? I can also play it by the bottle and add a pinch of acid blend every time I open one that went through MLF as the flavor is quite nice, it's just that the wine needs more acid. I'm open to suggestions.

Cheers,
Colin

 

[salcoco]

I would go a bottle at a time. if the carbonation is severe just swirl the wine once poured and the carbonation will dissipate.

 

[NoSnob]

In a very recent thread, I asked this question as a hypothetical - I had not had your experience. I asked if using a commercial wine for topping up a kit wine might initiate MLF. Very few responded but a very knowledgeable member (GreginND) on this board indicated that if a wine is adequately sulfited, it is unlikely to happen.

The Oxford Companion to Wine, a definitive tome, notes that lactic acid bacteria (which it states cause MLF) are intolerant of even moderate concentrations of SO2 and high concentrations of ethanol.

I can't help but wonder if just perhaps the lack of sorbate and maybe an incomplete fermentation resulted in continued in-bottle activity. I too would be interested in others opinions.

NS

 

[SandbaggerOne]

In a very recent thread, I asked this question as a hypothetical - I had not had your experience. I asked if using a commercial wine for topping up a kit wine might initiate MLF. Very few responded but a very knowledgeable member (GreginND) on this board indicated that if a wine is adequately sulfited, it is unlikely to happen.

The Oxford Companion to Wine, a definitive tome, notes that lactic acid bacteria (which it states cause MLF) are intolerant of even moderate concentrations of SO2 and high concentrations of ethanol.

I can't help but wonder if just perhaps the lack of sorbate and maybe an incomplete fermentation resulted in continued in-bottle activity. I too would be interested in others opinions.

NS

Hi NS,

I found all of that information as well. However, the wine was fermented to dryness (1.098 down to .995), I tried the wine in late December 1 month after bottling and it tasted tart like a young Barolo-style wine should and had no carbonation. The bottle I just tried the other day had slight carbonation and very low acidity and a hint of diacetyl. These are all hallmarks of MLF. Given my sulfite levels it seems crazy, but maybe something went wrong with my SO2 titration?


Salcoco: I have read that if MLF happens in the bottle the wine will eventually spoil. If this is what has happened I think rebottling makes sense.

Cheers,
Colin

 

[Pumpkinman]

Sandbaggerone,
I won't say that topping off with a commercial wine that has completed MLF cannot cause a wine to be inoculated with MLB, but I highly doubt it for several reasons.

~The first being that any reputable winery will test their wine for completion, we're not talking about a home winemaker that may stand to lose the cost of a batch of wine, we are talking about a commercial winery that not only stands to lose thousands of dollars in product, man hrs and their reputation.

~The second being that most commercial wineries will stabilize their wine very well to ensure that their wine has a long shelf life, again,they stand to lose thousands of dollars and credibility in the industry.

I would bet that the wine was not fermented to dry, that there was some residual sugar left in the wine and it started to ferment in the bottle, as far as the butterscotch flavors and carbonation , these can be justifies as a product of the yeast.

I would run a chromatography test to be certain.

 

[SandbaggerOne]

Thanks Tom, I'll take another bottle and check pH and run chromatography. I presume that kit wine should normally have very little tartaric and lots of malic acid so if I see high pH and lots of lactic acid MLF is indicated?

Thanks,
Colin

 

[Pumpkinman]

Yes, I wouldn't be too sure about lots of malic, the kits are supposed to be balanced by the manufacturer, this will be interesting to see the results.
Have you tested your hydrometer? even if it were off by 4 points, that would possibly leave enough sugar to start a mild fermentation.
Here is one way of calibrating your hydrometer using the 25 brix solution:

One way to tell is to calibrate it!
I read this on another wine forum, and Ironic enough, I found it in Wine Makers Mag as well.
To be absolutely certain your tools read correctly it is smart to check them from time to time, and easy way to check your hydrometer and refractometer is to make a 25 Brix solution.
Dissolve 25 g of sugar in 75 g of water (approx 1/3 cup), and you will have a 25 °Brix solution.
I had to make 2 batches to fill my hydrometer testing tube.
My Hydrometer and refractometer are spot on.

Here is the link to the article: http://winemakermag.com/127-calibrate-your-winemaking-tools

 

[SandbaggerOne]

Good ideas, thanks. I read somewhere that to prevent tartrate crystals kit wines are often heavy on malic acid, though I am sure it's not quite that simple. We'll see.

 

[ibglowin]

Are you sure the wine was properly degassed before bottling? What method did you use to degas?

 

[SandbaggerOne]

The wine spent 6 months in the carboy over several rackings and appeared fully degassed at bottling. The first bottle sampled had no gas. Also, the change in flavor and acidity was stark from December to now. I think it's more than poorly degassed wine.

 

[ibglowin]

The wine spent 6 months in the carboy over several rackings and appeared fully degassed at bottling.

This is your first clue. You can not tell if a wine is fully degassed by appearance! Kit wines can hold onto gas for long periods of time, especially if the winery is cold.

Only the chromatography test will tell accurately if you have any Lactic Acid present. Your going to have lots of Tartaric Acid as well.

 

[SandbaggerOne]

By "appear" I mean it did not evolve bubbles with agitation or during bottling, which I have seen before in wine and mead with residual gas at bottling, but obviously one can never be sure. I would not hesitate to agree with you if not for the lack of CO2 in first sample I tasted and the difference in taste between 1st and 2nd samples. We shall see. Thanks to all for the advice. I'll post my results later.

 

[Pumpkinman]

Thanks, I'm very interested in the results, we might all learn something new from this.

 

[SandbaggerOne]

My results are below. They are inconclusive in my opinion. I ran malic (M), lactic (L) and tartaric (T) acid standards. Next I ran the WE "Barolo" in question, and then an RJS Carmenere I just put in the carboy after primary. I played with the contrast and took color and high contrast B&W photos to highlight the acid spots. Both kit wines appear to have a little bit of lactic acid in them. the WE kit still has Malic as well, so if there was some MLF it did not run to completion. Is anyone surprised that a kit wine would have lactic acid?

Cheers,
Colin

 

[Pumpkinman]

To be honest, it appears to have more than just a little malic, these wines appear to be going through MLF in my opinion.

 

[SandbaggerOne]

Crazy. I guess I'll put some lysozyme in both and then check TA. I am really surprised that the Carmenere could be going through MLF a week after putting it in the carboy from primary.

 

[Pumpkinman]

May be a chance that it was already going through the process when you bottled.

 

[SandbaggerOne]

May be a chance that it was already going through the process when you bottled.

Yeah that seems likely.

 

[SandbaggerOne]

Any suggestions for cleaning up my winery? New tubing is a no-brainer. What about sanitizing the contaminated vessels. Iodophor? I am wary of bleach.

 

[vabeachbear]

Any suggestions for cleaning up my winery? New tubing is a no-brainer. What about sanitizing the contaminated vessels. Iodophor? I am wary of bleach.

At the winery I volunteer at, all vessels cleaned with OXY Clean.