Preventing Malolactic Fermentation

[Grey_Lion]

I’m getting a bucket of Chilean gewurztraminer juice next month and I’m planning right now.

I’d like to prevent malolactic fermentation in the carboy and in the bottle. Should I rely on acid and SO2 alone? Should I use lysosyme? Should I make sure sulfites are on the high end when I bottle? I don’t think I’ll be able to sterile filter. Are there any other considerations?

 

[Boatboy24]

Lysozyme is pretty cheap insurance and I'm not aware of any downsides in using it.

 

[JohnT]

This is an odd one. Most folks work hard to get MLF to happen.

Do you actually mean that you want to prevent additional alcoholic fermentation after bottling? This is different from malolactic fermentation.

If you mean alcoholic fermentation, I think most people use sorbate for sweet wines that have not undergone MLF. for dry wines, having little residual sugar (like mine), I have found that bulk ageing for a year or so prior to bottling will suffice.

If you do mean MLF, then you could simply raise the SO2 level to 30 or even 40 ppm. PH level and high ABV can also help to prevent unwanted MLF.

 

[Grey_Lion]

This is an odd one. Most folks work hard to get MLF to happen.

Do you actually mean that you want to prevent additional alcoholic fermentation after bottling? This is different from malolactic fermentation.

If you mean alcoholic fermentation, I think most people use sorbate for sweet wines that have not undergone MLF. for dry wines, having little residual sugar (like mine), I have found that bulk ageing for a year or so prior to bottling will suffice.

If you do mean MLF, then you could simply raise the SO2 level to 30 or even 40 ppm. PH level and high ABV can also help to prevent unwanted MLF.

Thanks for the help. Yes I do mean MLF. My understanding is that Germanic whites like Gewurztraminer and Reisling are more typically not taken through MLF.

 

[mainshipfred]

In whites I like the crisp taste the Malic gives and never allow it to go through MLF. Lysozyme and a higher dose of sulfites is my go to.

 

[user 36973]

Should I make sure sulfites are on the high end when I bottle?

For my whites, I hit them hard with Sulfites when fermentation is complete, add sorbate if I'm going to, and get them cold stabilized. I'll then top up with a light amount of sulfites prior to bottling. Never used lysozyme nor ever have had mlf in the bottle.

Truth to be told, I also sterile membrane filter the wine during bottling now, but that's for insurance on no yeast rather than so much for bacteria. However even before I started membrane filtering all my whites, I never had mlf in the bottle. The sulfites do sufficient work to kill them off.

 

[montanarick]

I always use lysozyme in my whites along with SO2

 

[Grey_Lion]

For my whites, I hit them hard with Sulfites when fermentation is complete, add sorbate if I'm going to, and get them cold stabilized. I'll then top up with a light amount of sulfites prior to bottling. Never used lysozyme nor ever have had mlf in the bottle.

Truth to be told, I also sterile membrane filter the wine during bottling now, but that's for insurance on no yeast rather than so much for bacteria. However even before I started membrane filtering all my whites, I never had mlf in the bottle. The sulfites do sufficient work to kill them off.

Thanks! What do you use for sterile filtration?

 

[user 36973]

Thanks! What do you use for sterile filtration?

I use a 10-inch "PES-plus-.45" membrane filter and the corresponding cartridge housing you can find under the Filtration link from stpats.com. Of course to keep from clogging the $115 filter immediately, the wine is pre-filtered through sequentially tighter pad filters down to 0.45 micron. I'll use the sterile filter on the wine on the way to the bottler.

These filter can be re-used if they are cleaned and stored properly. They also should be integrity-verified by nitrogen bubble point testing prior to (and after) bottling. I typically can get upwards of 1000 gallons through it before the filter get unusably clogged.

 

[Paolo_pin]

Lysozyme is pretty cheap insurance and I'm not aware of any downsides in using it.

I agree. Lysozime is a good way to stop MLF but it will work for short time only. It is affected by thermical degradation and it will subdue to proteic haze. This means, you will need to remove it with bentonite (difficult, thought) to keep the wine clear for further bottling.

 

[Paolo_pin]

Thanks for the help. Yes I do mean MLF. My understanding is that Germanic whites like Gewurztraminer and Reisling are more typically not taken through MLF.

True! In Germany, many Gewurztraminer are still with a little residual of sugar. Keeping such a wine microbiologically stable is difficult, so MLF is always not a good idea! They usually have high total acidity and low pH values (under 3,30). Also, primarial aromas are better preserved without MLF.

 

[Paolo_pin]

In whites I like the crisp taste the Malic gives and never allow it to go through MLF. Lysozyme and a higher dose of sulfites is my go to.

Actually, Lisozyme is going to be substituted by Chitosan, a fungal derivate acting against primarly Dekkera-like yeasts and any sort of bacteria. It works for a time way longer than Lisozyme and it does not carry haze problematics. Keep in mind, it does not affect Saccharomyces activity, so do not use it to stop alcoholic fermentation.