Can Commercial Top-Up Wine Activate MLF?

[NoSnob]

I do mostly kits and have also made several fruit wines. I have not (intentionally) taken any of my wines through MLF.

But, in topping up my kits I have used commercial wines which did go through MLF. I have always wondered if I am in fact adding a small amount of lactic acid bacteria that could undergo MLF & upset the balance of my kits when I top up with commercial wines.

I would not think so since kit instructions mention topping up with water or "a similar wine." What do you think?

NS

 

[JohnT]

It is plausible that MLF could be kicked off, but highly unlikely.

Most commercial wines maintain a level of SO2 that would most likely kill of any MLF bacterial (which is very sensitive to SO2).

 

[GreginND]

I presume you also maintain SO2 in your wines at a level to keep them stable. So, no, you should not have any problems.

Tiny point but terminology matters: - Lactic Acid Bacteria are everywhere. They are not the bacterial that converts malic acid to lactic acid. They convert carbohydrates to lactic acid. Think pickled fermented vegetables. Kimchi anyone? LAB are not the same bacteria we use for MLF. That requires malolactic bacteria.

 

[ibglowin]

I wish it were that easy, I would just buy a bottle of commercial wine and dump it in to my carboys after pressing instead of spending $30 on MLB, $5 on Opti Malo, setting up heating pads with timers, and then watching and waiting and testing for months on end…..

 

[WI_Wino]

I wish it were that easy, I would just buy a bottle of commercial wine and dump it in to my carboys after pressing instead of spending $30 on MLB, $5 on Opti Malo, setting up heating pads with timers, and then watching and waiting and testing for months on end…..

You should use a temp controller for those heating pads rather than timers. So much more precise. I have 3 that I built (STC-1000 DIY), 2 for heating (beer and wine) and 1 to run a freezer.

 

[NoSnob]

I presume you also maintain SO2 in your wines at a level to keep them stable. So, no, you should not have any problems.

Tiny point but terminology matters: - Lactic Acid Bacteria are everywhere. They are not the bacterial that converts malic acid to lactic acid. They convert carbohydrates to lactic acid. Think pickled fermented vegetables. Kimchi anyone? LAB are not the same bacteria we use for MLF. That requires malolactic bacteria.

Good point. Thanks
NS

 

[NoSnob]

Good point. Thanks
NS

I'm re-thinking my response to your comment. It has been a while since I took graduate level microbiology and worked in a clinical bacteriology lab so my memory may not be as good as it should be.

The Oxford Companion to Wine (p. 422) explains that MLF is the conversion of harsher malic acid in new wine to lower acidity lactic acid. It goes on to say that: "It is accomplished by LACTIC ACID BACTERIA, which are naturally present in most wineries but may have to be cultured and carefully introduced in newer establishments where malolactic fermentation is desired." It further notes that MLF should more accurately be called malolactic conversion as it is not literally a fermentation process.

As winemakers we refer to MLF bacteria as a kind of short-hand to refer to what technically is a specific type of lactic acid bacteria cultured for our use in smoothing out our wines.

Thanks for your comments. I found that The Oxford Companion also notes, as you suggest, that lactic acid bacteria are intolerant of moderate concentrations of SO2 and also of high concentrations of ethanol.

NS