Malolactic in Reds...Help me understand...

WINE TALK
1

Hi All;

Would appreciate some help in understanding the varying nature of ml fermentation in reds, its effect on palate, and on aging…

-What determines how a red wine enters and moves along in this process? Where does vessel (barrique, steel, foudre, etc) temp, inoculation, etc come into play with this.
-I’ve read that longer ml fermentations often promote greater “chemical” complexity, ie more molecular byproducts of fermentation. Is there any correlation to palate here?
-What determines whether a wine has residual malic acid? I noted that in DS last WA report on Oregon, he made note of the residual malic acid in the pinots there… What conditions promote this?
-Does malic acid help protect against oxidation and create longer aging wines?

My questions are based on a number of observations, including a preference for wines that may have some residual malic acid. Just noted quite a bit recently in a 2009 Montevertine Toscana…

Thanks!

2

Try a Terrano di Carso from Friuli (Refosco variation with NO Malo)…it’ll put hair on your tongue!

3

Reds prior to ml, at least the ones I’ve made, taste like green apple.

4

Malolactic fermentation happens when a bacteria (Oenococcus oeni) converts malolactic acid into lactic acid. These bacteria pretty much colonize any winemaking environment so this process will happen with all wines unless you explicitly stop it. There might be exceptions to this, but this has been my direct experience. Every wine Ive ever made has gone through Malolactic fermentation on its own without me inoculating anything. In Burgundy wines usually go through primary (alcoholic) fermentation in the fall soon after the grapes are crushed into must and then the malolactic fermentation happens in barrels after the cellars warm up a bit in the spring.

A winemaker should step in here, but Im surprised to hear this. Seems like this would be a huge risk for continual fermentation in the bottle unless they sterile filtered before bottling. I have bottles with bubbles in them because I didn’t let malo finish.

5

SO2 inhibits ml, just as it can be used to halt fermentation and leave residual sugar, in lieu of sterile filtering.

6

PH also has a say in Malo being able to start.

7

Once a fermentation is going full force I’d be curious to know how much so2 it would take to actually halt the fermentation. Many winemakers add so2 before fermentation because it kills weaker microorganisms but doesn’t stop s. cerevisiae. And so2 doesn’t last forever in wine. Eventually I think you might get some secondary fermentation in bottle. I’d be curious to know how German producers maintain the R.S. in their Rieslings. I do know that traditionally they didn’t stop fermentation and that the explicitly sweeter style is a more modern thing.

8

This simply means the wine has not completely gone through malo - hasn’t completely finished malolactic fermentation. All red wines go through malo, it is not a winemaking choice as it can be with certain white wines. Essentially, take the notes with a big grain of salt, as the wines are will not give a good representation of themselves while they are finishing.

9

]

I recently talked to Selbach-Oster (Mosel) about this and he said it was a matter of SO2. They have a reputation for using a lot of SO2, but they quality producers have worked hard to get the amount down and according to him it’s now 1/3 of what it used to be. Still, I don’t remember the exact number (he did say).

10

I can’t speak to the process, but I have had a few reds that have not gone through Malo and they have all had an obvious grapefruit flavor component. I remember one South American Carmenere where I commented at a tasting that there was a pronounced grapefruit flavor and the winery rep responded that it was because they stopped fermentation and did not allow it to go through malo. it was not spritzy.

11

Thanks all for your responses. There were a couple of reasons that I asked this question.

Recently, I tried to 09 Montevertine Toscana. I love Montevertine for its elegance, sense of energy, and longevitiy. The 09 was more tart than many vintages, and had an apple note that I associate with malic acid. It wasn’t my favorite vintage of this wine, but I then wondered if some red wine makers halt ML a bit short to assure there is some malic acid remaining to add lift, and whether malic acid itself is a preservative, or antioxidant of sort. Or, is tartaric acid the actual source of this “energy’” in red wines…

The second part of my question relates to some observations with my wife (who is 50% Asian) when she drinks some red wines. As you know, some Asians lack acetaldehyde dehydrogenase, which leads to an increase in aldehydes on drinking and causes flushing. We toured Piedmonte, where we our tastings included visits to Massolino and Vietti. At Massolino, she was able to drink a fair amount of wine with no flushing. At Vietti, about two sips caused a great deal of flushing.

I went on to note that the wines at Vietti go through a longer, slower ML than at Massolino. Further reading (you can google this with keywords “vasoactive amines, wine, and ml”) suggested that when wines go through slower ML, they tend to also spin off a greater number of side compounds, including vasoactive amines that cause flushing…

Drawing all of these threads together, I then wondered if winemakers control ml conditions and residual malic acid in order to create different effects in wines (or whether natural cellar conditions alter this), which leads to actual sensory changes in the wines themselves…

12

Heitz doesn’t let their cabernets go through malo. The wines tend to have a slight citrusy flavor that’s rare in cabernet, but it’s pretty understated. And I’ve had several older ones and none of them were refermenting. Don’t know what their filtering practice is.

13

Fixed

I’ve had a friend’s homemade wines that did this, and suspect it was from stuck malolactic fermentation. Once I get the fizz out, they aren’t bad though.

14

Yeah, it dissipates quickly with a decant.

15

That’s very interesting…although not citrus, I’ve often noted more of an “apple” flavor in younger Heitz Cabs, and it’s not necessarily a good one. I generally think their Cab is pretty weak whenever tasted at an early age. However, give them at least 5 years and they really turn the corner (more time needed for stronger vintages). In fact, lesser vintages from Heitz always seem to turn out decently, if not exceptionally well…I wonder if the lack of malolactic fermentation has something to do with it.

Speaking of weaker vintages, the 2003 Napa Cab is drinking quite nicely right now.

16

To stop whites going through MLF use lysozyme not sulfur. Also we will sterile filter whites that have not completed MLF to prevent bottles re-fermenting.

17

I think you’d get more response to this thread in the Cellar Rats forum, where it would get more attention from winemakers by not being knocked off the first page so quickly.

18

It’s somewhat ‘dangerous’ for reds not to go through ML, especially if they’re going to be aged in oak for some time. Malic acid is a precursor for some nasty microbial reactions that can take place over time, and therefore, by going through ML, the wine is more microbiologically ‘stable’ for the long haul. What types of byproducts can be created, you ask? Thinking back to wine micro bio, one of the things that stands out are ethyl carbomates, which, IIRC, are considered carcinogens.

I have experienced reds that ‘could not’ be pushed from ML due to very low pH’s - I remember a lot of Napa ‘Gamay’ that was brought in at the winery I used to work at that came in at a pH of 2.9 or something like that. As others have said, you usually see ML completed during the Spring, when things warm up. Some years, such as in 2012 when it was warm throughout harvest, you see unusually low Malic numbers to start with, and it’s not uncommon for some lots that are brought in early to undergo ML by the time the last grapes are picked.

Many wineries innoculate for ML to complete, usually adding at after primary is complete, direct to each barrel. Others will simply let it ride, and if your wines are stored in oak barrels, it will usually happen on its own given enough time. Many wineries like to know it’s going to be completed in a ‘timely’ manner, for as soon as it’s completed, you can add SO2 and minimize the risk of early oxidation of the wines.

In the case of Heitz, I’d love to know whether they truly did not go through ML on their reds - it would be surprising.

And as someone pointed out, lysozyme can be used to ensure ML is not completedn this occurs most often with white wines . . . but in most cases, decent amounts of SO2 will do the trick as well.

It is not uncommon to ‘note’ a ‘buttery’ quality in some red wines after ML is completed, but these aromatics usually seem to go away with a few more months of barrel aging.

Hope that helps . . .

19

Hi Larry;

Thanks for your reply.
My understanding is that with whites, many are kept from going through complete ML fermentation…
Why are reds with residual malic acid less stable than whites?

20

What about Rose? MF or not?