Malolactic Fermentation: When do you introduce bacteria?

[crushday]

I thought I would start an open discussion on when to introduce bacteria for the malolactic fermentation (MLF) when fermenting wine from fresh or frozen grapes. Note: MLF is not suggested for kit winemaking.

Personally, I have a tremendous success adding the bacteria during alcoholic fermentation and after the formation of the first solid cap. In my experience, the bacteria doesn't interfere with the yeast and the yeast and bacteria are not competing for resources in any noticeable way, and ALL my co-inoculations have completed WITHOUT the use of malo nutrients.

I'm afforded this option because of where I live. My friends south of me in North Central California (@NorCal @4score @CDrew @Busabill) simply do not have this option due to the heat index of their respective environments as it relates to must temperature and the specs of most bacteria. Where I live, in the Pacific Northwest, I don't experience the sustained high temperatures in my weather. So, unlike the afore mentioned gentlemen, my garage doesn't get 120 degrees.

I recently fermented 1000 pounds of fresh Carménère grapes. My garage had an average ambient temperature of 50. I had to split the fermentation to two vessels. The fermentation temperature maxed out at 69 and 70 degrees. I averaged a temp of 60 during the fermentation. Because I co-inoculated, and the bacteria (Oenos in fermentor #1 and Ch16 in fermentor #2) had a low spec of 62 degrees, I wondered what would happen. In short, the fermention temperatures averaged at a level BELOW the low spec of the bacteria - and, had no difficulty completing on time.

When do you inoculate bacteria for MLF? Have you ever had a MLF not complete?

 

[cmason1957]

I am in MO and deal, mostly, with hybrid grapes. Mostly Norton and Chambourcin, occasionally St. Vincent. I ferment in my basement where the ambient temp never exceeds 68F during October. I have in the past done Chilean Juice buckets, but decided not to any longer.

Previous years, I have added Malolactic Bacteria after fermentation completed and racking off the gross lees. I have used several types of bacteria Ch16, oenos, enoform alpha and beta. Always adding some nutrients. It's what the books say to do. Always completed, generally expected two to four months time frame. This year's grapes, based on experiences of several members, I added my MLB after we had a good cap. I did notice just a slight off smell the very last day of fermentation, prior to pressing. Malo finished about two weeks after alcohol fermentation, the off smell is gone and the wine tastes and smells as expected.

I have never had Malo not finish. Except for one of two of the Chilean Juice buckets. I plan to continue with the co-inoculation. Even though me wife threatened my life when I told her we were doing something different with Her Chambourcin.

 

[CDrew]

@crushday I am loving your experimental approach to the Carménère fermentation in your other thread. I wish there were time for more such experiments!

But you are right-that here in Norcal we have very little environmental control. The one control I have is inside vs outside in the garage. The nights are cool here though (commonly mid 90s in the day time and mid 50s at night), and so a September fermentation in the garage may briefly hit 80F-85F at peak, usually it's less (mid 70s) and so far has not caused a problem. If the grapes can last until October, the fermentations are typically at more "perfect" wine temperatures. What the warmth does do is give 100% reliable MLF. Like you, I add the culture with the formation of the first cap. I have used CH16 mostly and this year used VP41 for the first time on my Primitivo, I was lazy about testing this year, but when I did test at 1 month, both were complete.

I am intrigued by the idea, that different MLF cultures may give different flavors as you found with the Oneos. I be very curious if this difference persists over time.

Regarding nutrients, the CH16 says to inoculate directly and so that's what I do. The VP41 says you can do that too, but recommends a re hydration/nutrient step and so I did that. No additional nutrients.

Depending on your conclusions, I may try a different MLB strain next year, especially with a later and cooler fermentation. We had a weird year this year in that the grapes were early do to extra heat during the growing season. I picked Syrah in late August for the first time in 6 years. Usually its a month later.

 

[BarrelMonkey]

I always inoculate when primary fermentation is complete - taking care that, as far as I can tell, it fermented dry. I do this largely because that's what I learnt, obviously some folks have great success with coinoculation.

I am currently trying to figure out what to do with a (potentially) stuck MLF. I am making an elderberry wine, and decided to try MLF since my first attempt last year ended up rather tannic and astringent. (I also tried to tame this astringency by doing an extended cold soak before pitching yeast, and pressing out before primary fermentation was complete. And yes, I am aware that most people say that elderberry needs a lot of time to become approachable...)

I did get some initial ML bubbles but the weather became cold and I think it's stuck (chromatogram here). No current signs of activity for several weeks now. Note the extra fat band of citric acid, which elderberries have in abundance. There is a minor malic band and maybe some evidence of lactic conversion, but doesn't look complete to me. I'm trying to decide whether to leave it until it warms up in the spring (with the attendant risk of something unwanted starting to grow), or to just sulfur it now and declare my elderberry ML experiment as only partially complete.

 

[distancerunner]

We usually pitch the MLF bacteria a day or so after the yeast. This year I fumbled and was surprised to find there was no MLF bacteria in the fridge when I pitched the starters. So it was pitched five or so days behind. (Where was the pre-fermentation check list?)

CH-16, not hydrated. Might change that next ferment. Certainly would be easier to dose into five or six fermenters. The only agitation it receives is during punch downs, which we now try to do as gently as possible after the first few days.

Cellar temperature is roughly 68°F. It will drop four or five degrees as winter progresses. At those temps CH-16 has never failed to finish. I hold off on cold stabilization until the tests show each vessel has completed MLF.

I'm running a test tomorrow to see how far along it is. Hoping it's done.

 

[Markybones]

We usually pitch the MLF bacteria a day or so after the yeast. This year I fumbled and was surprised to find there was no MLF bacteria in the fridge when I pitched the starters. So it was pitched five or so days behind. (Where was the pre-fermentation check list?)

CH-16, not hydrated. Might change that next ferment. Certainly would be easier to dose into five or six fermenters. The only agitation it receives is during punch downs, which we now try to do as gently as possible after the first few days.

Cellar temperature is roughly 68°F. It will drop four or five degrees as winter progresses. At those temps CH-16 has never failed to finish. I hold off on cold stabilization until the tests show each vessel has completed MLF.

I'm running a test tomorrow to see how far along it is. Hoping it's done.

How long does mlf usually take, say at 65 to 70 degrees, or so?

 

[GreginND]

I have settled on adding my MLB a day or two after fermentation becomes really active. I find that MLF is done quicker with the aid of a bit of sugar to help feed it and the heat of fermentation.

 

[distancerunner]

I have settled on adding my MLB a day or two after fermentation becomes really active. I find that MLF is done quicker with the aid of a bit of sugar to help feed it and the heat of fermentation.

How does sugar figure into promoting quick MLF?

 

[justsgm]

I always wait until fermentation is complete and I have racked off the gross lees before adding malo. Never had a problem.

 

[Nebbiolo020]

I always add it right after primary finishes before I press the wine and move to secondary/ malo in stainless tanks. I also like to add malolactic bacteria nutrients to every malo cause it helps a lot with reducing off flavors and helps to get a complete malolactic fermentation. Although I have never had a stuck fermentation with laffort b7 direct which is my favorite malolactic culture because it’s reliable and always does the job.

 

[jburtner]

This year I Added VP14 after the yeasties started working which was almost four weeks ago. One carboy has tiny bubbles and the other no apparent activity. I did rack off the gross lees a day or two after pressing. I keep them wrapped in reflectix with a heating pad on low. Keeps them in the mid 70’s while the cellar is 62-65*F. Have not made a chromatagram yet. Might wait till spring. They’re topped up and under airlock.

Cheers!
-johann

 

[wood1954]

I’ve used Wyeast and ch16 to no effect, so now I use VP 41 after the yeast get started. So far so good.

 

[Nebbiolo020]

I’ve used Wyeast and ch16 to no effect, so now I use VP 41 after the yeast get started. So far so good.

Wyeasts malolactic blend is pretty reliable, CH16 is a nightmare and none of the commercial wineries use it anymore cause it sticks and likes to not finish.

VP-41 is good, so is MBR-31, I prefer Laffort B7 direct it costs $25 per 66 gallon dosage and is reliable never sticks and finishes with no off flavors it’s just a better culture price wise and more reliable.

You can order it online from laffort.

 

[crushday]

CH16 is a nightmare and none of the commercial wineries use it anymore cause it sticks and likes to not finish.

Such an interesting collection of words to read, and words that don't match my personal experience. I've never had a MLF not finsih using CH16. When I say finish, I don't mean limp across the finish line.

 

[CDrew]

Such an interesting collection of words to read, and words that don't match my personal experience. I've never had a MLF not finsih using CH16. When I say finish, I don't mean limp across the finish line.

I agree. CH16 has been 100% reliable over 7 years. It's a very strong ML fermentor. Maybe Neb got a bad packet? I pick mine up out of the freezer at Lodi Wine Labs and never even a hint of an issue.

With that said, I used VP41 this year for the first time, and it too, worked fine. But the reason I used it was that Lodi Wine Labs was out of CH16, so that alone says something since they cater to commercial wineries.

 

[BarrelMonkey]

I agree. CH16 has been 100% reliable over 7 years. It's a very strong ML fermentor. Maybe Neb got a bad packet? I pick mine up out of the freezer at Lodi Wine Labs and never even a hint of an issue.

With that said, I used VP41 this year for the first time, and it too, worked fine. But the reason I used it was that Lodi Wine Labs was out of CH16, so that alone says something since they cater to commercial wineries.

Another vote for CH16 here. I used it for my 2021 pinot noir and it was a rock star. (Purchased from my LHBS and transported on ice, if that makes a difference...)

 

[Nebbiolo020]

Such an interesting collection of words to read, and words that don't match my personal experience. I've never had a MLF not finsih using CH16. When I say finish, I don't mean limp across the finish line.

One of the wineries that I worked at had used it for like 15 years under the original winemaker and had a long history of stuck malolactic fermentations since day 1 basically and we changed over when he left to a different strain and have had no issues since then.

I have personally heard of other wineries having issues with it and most wineries around me have started using laffort or enartis products exclusively. Not saying other people haven’t made it work just in my experience it’s needed nutrients and adding more malolactic bacteria back and various other help to get it to complete.

 

[Johnd]

Interesting responses @crushday , you already know I’m a co-inoculator, very surprised how many other folks are too. If you’d asked this question 6 or 7 years ago, you’d probably have found the results completely opposite. Hell, even @cmason1957 gave it a shot, a lifelong post-inoculator!!