Lactobacillus?

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David Violante

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I’m curious about a DeChaunac I’m fermenting.

The grapes were beautiful and I sorted, destemmed, and crushed two lugs. There were a couple of clusters that seemed to have some kind of powdery mildew or grey rot and I disposed of them and the ones around them. I ended up with 5 gallons of must with a pH of 3.2 and SG of 1.060. It smelled and looked great. I added ¼ teaspoon of potassium metabisulfite and let it sit overnight covered with a towel.

The next day, there was a light similar grey coating on the top of the must as was on the clusters I discarded. I probably should have ended it all there but being the optimist I forged on. Another ¼ teaspoon of sulfite and another day. No coating, no bad smell, no bad look… pH and SG the same. I added Pectic Enzyme and yeast inoculated in GoFerm. As an afterthought I took a sample to look at under a microscope and but didn’t really see anything that stood out (Image A). The fermentation went well with a median temperature of 78F. I used a step feeding protocol of Fermaid O, K, and DAP at 24, 48, 72 hours, and at 1/3 break. At an SG of 1.010 I transferred to a Fermonster under airlock.

After a few more days and no appreciable CO2 production, there again appeared a grey film on the top (Image B). Another set of microscope slides at 400x (Image C) and 1000x (Image D). After some research, this looks quite like Lactobacillus perhaps fructivorans. Long rod-like structure of bacillus, with single to double segments. Double dose of sulfite and press off the gross lees. Wash and decontaminate everything with soap and water, StarSan, and then a strong sulfite solution, twice. More research.

The wine doesn’t smell bad and there’s no bad taste either. Actually, there’s no real taste at all with it. After Joe’s posting about the Chardonnay, I thought I better see if I can taste or smell anything else and I can for sure smell the sulfite and taste other things. I’m letting it sit to clarify and see if there’s any difference. I’m thinking of just dumping it and super cleaning / sterilizing all the equipment again. There are no signs of similar activity or result with any of the other wines I did at the same time as this one (Frontenac, Concord, Apple).

Any thoughts on what’s going on or if I could have done anything differently?

Some of my research sites that had great information:

  • UC Davis Viticulture & Enology, Microscopy for the Winery: Microscopy for the Winery
  • Bartowsky, Evelyn J. (2009). Bacterial spoilage of wine and approaches to minimize it. Letters in Applied Microbiology. (48) 2 (p149-156). Error - Cookies Turned Off
  • Dharmadhikari, Murli. (orig 1992). Lactic Acid Bacteria and Wine Spoilage. Iowa State University Extension and Outreach, Midwest Grape and Wine Industry Institute. Lactic Acid Bacteria and Wine Spoilage

Image A.jpg Image B.jpg Image C.jpg Image D.jpg
 
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I looked up the fructivorans; it doesn't seem to produce the effect you described. However, it apparently likes CO2, so degassing may help if this is it.


Did you chaptalize? 1.060 is a low SG, producing ~8.5% ABV, so I'd have bumped it to at least 1.085. Higher alcohol kills a lot of critters.

Once fermentation is 100% complete, I'd hit it with kieselsol/chitosan to precipitate as much particles as possible. I have no idea if that will help, but it won't hurt.

Regarding the taste, here's food for thought. In my Wine Stix Experiment, we experienced a dramatic downturn in taste in all 4 carboys at the 5 July 2021 tasting. This corrected itself by the next tasting. I'd hold some hope that the wine will improve. You can always dump it later.
 

Rice_Guy

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* you have the correct shape organism for genus lactobacillus. (excellent microscope) (I have no idea what species differences would be)
* lactobacillus will live under anaerobic conditions therefore normal headspace won’t help. It also tolerates the acidic environment therefore normal pH isn’t helpful.
* lactobacillus requires a food source, do not back sweeten.
* free SO2 will work as well as alcohol content, one of the preventatives is to have a high enough innoculum to quickly get 5% alcohol in the system, ,,, and 11% is more effective, ,,, as with flowers layer grain alcohol on the surface or add enough to get the mass to 14%.
* filtration would be useful, even if you don’t have a 0.45 membrane cutting the population makes other treatments more effective, ,,, it is a maximum population number game.
* in a factory environment rubber parts would be replaced since cracks can hold innoculum. Consider putting your siphon tubing in the bucket where you make sanitizer for a week or replace the tubing.

* on the positive side, lactobacillus is not a food poisoning organism, so it won’t hurt you, just skew the acid flavors
* lysozyme is a bacterial tool, it might be another protective barrier.

good luck, a winery in my home area which also made kombucha fights lactobacillus
 

David Violante

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* you have the correct shape organism for genus lactobacillus. (excellent microscope) (I have no idea what species differences would be)
* lactobacillus will live under anaerobic conditions therefore normal headspace won’t help. It also tolerates the acidic environment therefore normal pH isn’t helpful.
* lactobacillus requires a food source, do not back sweeten.
* free SO2 will work as well as alcohol content, one of the preventatives is to have a high enough innoculum to quickly get 5% alcohol in the system, ,,, and 11% is more effective, ,,, as with flowers layer grain alcohol on the surface or add enough to get the mass to 14%.
* filtration would be useful, even if you don’t have a 0.45 membrane cutting the population makes other treatments more effective, ,,, it is a maximum population number game.
* in a factory environment rubber parts would be replaced since cracks can hold innoculum. Consider putting your siphon tubing in the bucket where you make sanitizer for a week or replace the tubing.

* on the positive side, lactobacillus is not a food poisoning organism, so it won’t hurt you, just skew the acid flavors
* lysozyme is a bacterial tool, it might be another protective barrier.

good luck, a winery in my home area which also made kombucha fights lactobacillus
Thank you…. I’ll bring up the alcohol content to the 14% mark and later some grain on top although I don’t have any filtration equipment. There aren’t any rubber parts in the equipment I used for processes of crushing and storing (except for the fermonster so I’ll replace that gasket) but I’ll sanitize those other plastics for a week. Will the same be true for glass pieces (hydrometer and carboy) and should I do the same with the pH meter?

I did use pectic enzyme, but I’ll get some lysozyme as well.
 

David Violante

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I haven’t heard this much here, what about UV sterilization of equipment?

As a followup, I know we’re supposed to protect wine from sunlight over time, would a short exposure to UV work also?
 

stickman

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Based on your posts so far, I assume you were not planning on conducting ML fermentation. Your wine is in a carboy and topped up, so at this stage of the process the main issue is maintaining the proper molecular SO2 for the current pH. The must started at 3.2 pH which is more selective towards oenococcus than lactobacillus, and that's a good thing. What is the current pH? Final gravity?

I wouldn't panic, just proceed as normal for a wine that still has malic acid present which means it will always have a food source for bacteria. The advice from others above is good, clarify the wine, lysozyme is an option if you don't have a filter, bottle with proper SO2, and enjoy.
 

David Violante

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Based on your posts so far, I assume you were not planning on conducting ML fermentation. Your wine is in a carboy and topped up, so at this stage of the process the main issue is maintaining the proper molecular SO2 for the current pH. The must started at 3.2 pH which is more selective towards oenococcus than lactobacillus, and that's a good thing. What is the current pH? Final gravity?

I wouldn't panic, just proceed as normal for a wine that still has malic acid present which means it will always have a food source for bacteria. The advice from others above is good, clarify the wine, lysozyme is an option if you don't have a filter, bottle with proper SO2, and enjoy.

I would have loved to do ML but this sort of dead ended that idea. Unless I can use lysozyme and wait for the sulfite amount to drop a little then use something like CH16 or one that works in a lower pH a bit later on. I’ll have to get some more numbers for you…
 

David Violante

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Surprisingly, the pH is 2.8. I calibrated with new packets and rechecked. Still 2.8. SG is 1.000 so that’s ~12%. I’ll have to bump it up a little. I did another slide from the center of the wine carboy and it seems pretty barren considering the ones from the must previously… you’re going to have to zoom in to see the very few ones present.

C5C365CD-E869-46C0-818B-ED934CAFC611.jpeg
 

Rice_Guy

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the issue on rubber is that over years it cracks which creates harborage for contaminants, stainless as well as glass do not crack. Plastics can crack but for PET carboys a bigger issue would be scratches. Factory rule is always use soft brushes/ NO scratches.
. . Will the same be true for glass pieces (hydrometer and carboy) and should I do the same with the pH meter?
I do not put my pH samples back in the fermentation, since I can’t really sanitize the probe. The quantity is small and usually ends up as a taste sample to check the progress.

Yeast pushes the pH lower with CO2 so I am not surprised to see pH 2.8. If I am running soda or cider I degas the sample first.
 

David Violante

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So it looks like I’ll be ok with all the glass components.

In the past I’ve just used my pH meter right in the must but I now see several reasons for not doing so (including accidentally dropping said meter into the mix). Taste sample it is. Thank you for the process change.

I don’t use brushes on the Fermonsters or the plastic containers, just PBW, StarSan, and sulfite with a paper towel. I also soak the spigots in those solutions, but I’m moving away from spigots as they clog with the lees and don’t seem so useful compared to the surface area / crevices and hiding places involved.

Thank you tons for the advice and help.
 
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