when to add malolactic culture (Grenache)

[Crm]

Does anyone have experience or opinions about when to add malolactic culture to Grenache grapes and juice?

 

[Johnd]

Does anyone have experience or opinions about when to add malolactic culture to Grenache grapes and juice?

My opinion is to co inoculate, adding the MLB culture at the first signs of fermentation.

 

[BernardSmith]

Why do some say to inoculate with MLF after you have racked off gross lees?

 

[Johnd]

Why do some say to inoculate with MLF after you have racked off gross lees?

Some winemakers inoculate with MLB after fermentation (sequential MLF), not wanting to have the yeast and MLB competing for nutrients, which can cause some problems if both aren't properly fed. Once you've removed the gross lees, you shouldn't have to rack for a while, and therefore not leaving any MLB behind in the lees, which is why adding the culture after that gross lees racking is practiced if you do sequential inoculation.

 

[BernardSmith]

Thanks, Johnd. That makes good sense. I had been thinking that the issue was more about something in the gross lees which might create problems for MLF but your point is very different. Racking off the lees after inoculation may result in a large proportion of the bacteria being left behind.

 

[Crm]

So you would recommend adding MLB after racking off the gross lees? Is there any problems if you don't quite have the recommended amount of MLC?

 

[Johnd]

Thanks, Johnd. That makes good sense. I had been thinking that the issue was more about something in the gross lees which might create problems for MLF but your point is very different. Racking off the lees after inoculation may result in a large proportion of the bacteria being left behind.

Exactly, can't leave too many of the little buggers behind. Here's my unsolicited soap box speech about sequential vs co inoculation.

My personal belief, based upon what I have read and understand about MLB is as follows:

MLB is sensitive to the following characteristics of our wine:

1. All MLB are sensitive to low pH, the number varies by strain, but in general, being at 3.3 or higher is better, too low is a no go
2. All MLB are sensitive to alcohol, so the higher the ABV, the worse it is for the MLB to do their job
3. All MLB are sensitive to the presence of sulfite, the concentration differs by strain, but anything above 50 ppm is a killer
4. All MLB are sensitive to temperature, too cool and they go really slow, in the right range they roll along, too hot can kill them.
5. MLB need nutrients to perform their task, whether it's from the skins and pulp or added nutrients, they need food

If you have four factors in line, and one on the edge, you'll probably succeed, get two on the edge, success is limited, get three out of range, and you're MLF is probably doomed. This led me to try co inoculation years ago, despite the warnings, for the following reasons:

1. I can control pH enough to get it in range prefermentation, this is a biggie in my book.
2. At the start of alcoholic fermentation, the ABV of your must is 0%, or very close to it. As the ABV rises, the MLB acclimate to it slowly, instead of being dumped into a 14% wine.
3. If you don't sulfite your grapes after crushing, which I don't, the sulfite content in the must at the addition of MLB is 0.
4. MLB pitched at the beginning of alcoholic fermentation enjoy moderate temperatures, fueled by the heat of AF, and thrive in those temps.
5. A must that still contains all of the skins, seeds, stems and pulp has a lot more available nutrients for the MLB than one that has completed AF, been pressed, and racked off of the gross lees.

Based on the way that I make wine, I figure that I can get 100% of the factors in line before my MLB ever hits the must. That, coupled with rehydrating with Acti-ML and feeding with OptiMalo, almost makes success foolproof, which I really wanted in my procrastinatory winemaking style. As an added bonus, MLB us usually completed within a few weeks of the wine being pressed and racked off of the gross lees, meaning you can get it sulfited and protected more quickly than sequential inoculation.

 

[bjoll001]

I have always done co-innoculation (inoculated with ML bacteria 24-48 hours after yeast pitching) with good results. The Malolactic fermentation seems to finish consistently doing this.

This year I am doing both co-innoculation and sequential innoculation.

For my Pinot Noir, I inoculated after racking off the gross lees and used ML nutrients
It took over 1.5 weeks after innoculation to notice steady bubbles in the carboys. In the past doing co-inoculation, these bubbles are noticed 1 day usually after racking off gross lees because ML fermentation has already started.

There are good studies out now showing co-inoculation finishes ML fermentation a lot sooner than sequential and is consistent with no off flavors. The idea that the ML bacteria and yeast compete for nutrients has been proved incorrect in these studies.

For my Cab Franc this year, I am doing co-innoculation. What is nice about co-innoculation is you do not need to add ML nutrients because the must has good nutrition already and some excess yeast nutrients can be used by the ML bacteria (not all as ML bacteria does not use DAP for instance) leaving less or none behind for other organisms to feed on later after yeast fermentation. As ML continues, the fine lees supply nutrients needed after racking off gross lees.

I will be comparing both the time for sequential and co-inoculation when they are down. Sensory wise, not a great comparison as pinot and cab franc are very different.