Brewing Master

Question:

Clyde, Ed, Dave, Lum, RottenGrapes….Thank you all for your thoughts on using ML fermentation to lower the TA in my red wines.   Obviously there is a lot to know about this whole winemaking process~should have started years ago but I was busy with things like work, raising a family and didn’t have the vineyard. Next fall I plan on being more patient with the grapes letting them hang until the TA falls further than in years past (weather and other factors permitting).  Lum had previously discussed other methods to lower TA which I will try if needed and I should have enough grapes to try fermenting with and without ML to experience the results first hand.   It’s interesting to note that my year 2000 Baco Noir and Leon Millot wines show the presence of tartaric, malic and lactic acid so some sort of ML conversion is going on even tho I didn’t innoculate with a ML culture (both wines have very slow bubbling thru the airlocks).  This is the third year I’ve made wines from these grapes and they actually taste like a dry red wine should taste (IMO). So there is hope for these grapes. Meanwhile I have a row of Nortons started last spring and after tasting the Stone Hill version I know these will make a great red wine in years to come. Thanks again for the help. Bill Frazier Olathe, Kansas

Response:

Hi Bill: Winemakers wishing to minimize the formation of diacetyl during a MLF should add the ML inoculum while there are still active yeast in the fermentation, &/or leave the wine on the lees throughout & after the ML. Both yeast & active ML bacteria will catabolize the diacetyl, thereby eliminating/minimizing the buttery character. The above factor is one reason why red wine are generally allowed to rest on the lees, without SO2, for longer periods than whites. With respect to your specific questions: If true would you add the ML culture at the same time as regular wine

yeast? You can, and many do.  I usually add my ML culture near the end of fermentation, but while the yeast are still active. Would you avoid any SO2 addition at time zero?

I usually add 30ppm.  Also, by waiting till near the end of the regular fermentation before adding the ML inoculum, the winemaker can rest assured that the free SO2 has "blown-off" (either reacted with wine consituants or dissapated) by the time he/she add the ML bacteria. If true, since there is no SO2 protection, would you avoid cold settling before fermentation?

No.  Cold soak is fine under the 30ppm and cold temps.  Just use a container which can be well sealed. Finally,  does anyone have experience with Lallemand 71B-1122 yeast?  I understand this yeast will metabolize 20 to 40% of malic acid.  For those with experience with this yeast would you use it for a big red wine?

I use it, but only for Germanic whites. My standard protocol for reds is: Lalvin RC-212, allow temp to peak at 90F, add ML inoculum near Brix 0,  Cuvaison (must left on skins) for 14-21 days (pushed down twice daily & protected with plastic sheets & inert gas), wine pressed & transferred to inert containers for the completion of MLF, wine left on lees for 3-6 months with one stirring (midway through), wine racked in late winter/early spring & free SO2 added, if possible wine is thoroughly chilled at this time, after chilling, rack, adjust free SO2 & follow standard aging timeframe. The long period of aging on the post-pressing & ML lees pretty much ensure that all of the diacetyl will have been catabolized by the yeast & bacteria. In closing, I believe that you will find it nearly impossible to make a high quality, big, dry, red from either Baco or Millot without a complete MLF. Hope this helps. Prosit: Ed — The Viticulture FAQ & Glossary – http://www.itsmysite.com/vitfaq           "I like on the table, when we’re speaking,            The light of a bottle of intelligent wine."                               -Pablo Neruda

Response:

Hi Bill, Diacetyl is one of several materials produced by ML bacteria.  Diacetyl has an odor much like butter, and diacetyl in wine can modify aroma characteristics significantly.  Generally, changes in wine aromas are subtle, but some wines like Chardonnay are often enhanced by very small quantities of diacetyl. Experienced winemakers produce specific wine styles by skillfully managing ML fermentation. Diacetyl is produced and metabolized by both ML bacteria and yeast.  When ML fermentation occurs during primary fermentation or while wine is aging on active yeast lees, most of the diacetyl produced is metabolized by the yeast, and little diacetyl remains in the wine.  A similar situation occurs when ML bacteria are allowed to remain in the wine after malolactic fermentation has been completed.  Here, the bacteria consume the diacetyl, and after a few weeks little diacetyl remains in the wine.  Sometimes winemakers leave larger amounts of diacetyl in the wine to produce the buttery characteristics so typical of a full-bodied Chardonnay. When a winemaker wishes to leave larger quantities of diacetyl in the wine, he uses the following strategy.  (1) When primary fermentation is complete and much of the yeast has settled, the wine is racked off the gross lees.  (2) The wine is inoculated with ML bacteria.  (3) The ML fermentation is carefully monitored at least once each week.  (4) When ML fermentation is complete, the winemaker adds about 50 milligrams per liter of sulfur dioxide to the wine, and the sulfur dioxide kills the ML bacteria before they can metabolize the diacetyl. Considerable diacetyl can be left in a wine using this technique. At other times, the winemaker may choose to leave little diacetyl in his wine. Here, he uses a different strategy.  (1) The wine is inoculated with malolactic bacteria either during or just after the alcohol fermentation when many viable yeast cells are present in the wine.  (2) When ML fermentation is complete, both the yeast lees and the bacteria are allowed to remain in the wine for several weeks before any sulfur dioxide is added.  During this time, the yeast and the bacteria consume much of the diacetyl.  (3) When most of the diacetyl is gone, the winemaker adds about 50 milligrams per liter of sulfur dioxide to kill the bacteria.  The winemaker then uses standard winemaking procedures to clean up the wine. Regards, lum

– Hide quoted text — Show quoted text – This continues a question I had about using malo lactic fermentation to reduce acid in red grapes I grow (Baco Noir and Leon Millot).   References to wines that have undergone ML fermentation mention buttery flavors.  I asked if this flavor was due to diacetyl and the answer was yes.  In beer making diacetyl is usually considered a defect so I was surprised to find that in wines this flavor was considered desirable. RottenGrapes was nice enough to provide web sites that list wines that have had complete ML as well as no ML fermentations.  Chardonnays were the wines listed with ML information.  I bought two of them (ZD-non-ML and Cambria-100% ML).  Both wines tasted completely different.  The non-ML ZD was very fruity~I loved it.  The Cambria (ML) tasted like most Chardonnays I have had over the years.  I’m not a big fan of Chardonnays and I now believe ML fermentation (diacetyl ??) is the reason (NOTE:  having said this I’m finishing the Cambria as I type and it’s a good Chardonnay-I just liked the non-ML wine better). This brings me back to my original quest-a natural method to reduce TA in red grapes.  I just finished pruining my vineyard yesterday and I’m looking forward to a good hot summer here in Kansas.  I plan to let the grapes hang longer than in the past (just say no to pH) and try to let TA fall while the grapes are still on the vine.   However, if acid is still too high I would consider using ML fermentation if the Chardonnay-like flavor can be avoided or minimized.  Common sense says that if I want to avoid diacetyl in my finished red wines I should have ML fermentation going on during the most vigorous phase of fermentation, so the diacetyl is vented with CO2. If true would you add the ML culture at the same time as regular wine yeast? Would you avoid any SO2 addition at time zero? If true, since there is no SO2 protection, would you avoid cold settling before fermentation? Finally,  does anyone have experience with Lallemand 71B-1122 yeast?  I understand this yeast will metabolize 20 to 40% of malic acid.  For those with experience with this yeast would you use it for a big red wine? Thanks for the input. Bill Frazier Olathe, Kansas

Response:

Something different but on the same topic … I have a batch of red wine (from grapes) that I made last fall.  I added minimal SO2 after the first racking (about 4 weeks after the end of fermentation).  I can’t remember off the top of my head (it is in my notes) but I think I put in about 40-50 ppm.   Could I still do a MLF on this batch?  I know that the bacteria is sensitive to SO2 but if the levels drop to a certain point, can the ML bacteria start its work?  Or should I just chalk this one up to a learning experience and try it again next year … -Chris

Response:

- Hide quoted text — Show quoted text – This continues a question I had about using malo lactic fermentation to reduce acid in red grapes I grow (Baco Noir and Leon Millot).   References to wines that have undergone ML fermentation mention buttery flavors.  I asked if this flavor was due to diacetyl and the answer was yes.  In beer making diacetyl is usually considered a defect so I was surprised to find that in wines this flavor was considered desirable. RottenGrapes was nice enough to provide web sites that list wines that have had complete ML as well as no ML fermentations.  Chardonnays were the wines listed with ML information.  I bought two of them (ZD-non-ML and Cambria-100% ML).  Both wines tasted completely different.  The non-ML ZD was very fruity~I loved it.  The Cambria (ML) tasted like most Chardonnays I have had over the years.  I’m not a big fan of Chardonnays and I now believe ML fermentation (diacetyl ??) is the reason (NOTE:  having said this I’m finishing the Cambria as I type and it’s a good Chardonnay-I just liked the non-ML wine better). This brings me back to my original quest-a natural method to reduce TA in red grapes.  I just finished pruining my vineyard yesterday and I’m looking forward to a good hot summer here in Kansas.  I plan to let the grapes hang longer than in the past (just say no to pH) and try to let TA fall while the grapes are still on the vine.   However, if acid is still too high I would consider using ML fermentation if the Chardonnay-like flavor can be avoided or minimized.  Common sense says that if I want to avoid diacetyl in my finished red wines I should have ML fermentation going on during the most vigorous phase of fermentation, so the diacetyl is vented with CO2. If true would you add the ML culture at the same time as regular wine yeast? Would you avoid any SO2 addition at time zero? If true, since there is no SO2 protection, would you avoid cold settling before fermentation? Finally,  does anyone have experience with Lallemand 71B-1122 yeast?  I understand this yeast will metabolize 20 to 40% of malic acid.  For those with experience with this yeast would you use it for a big red wine? Thanks for the input. Bill Frazier Olathe, Kansas

Hi Bill, Here’re some random thoughts on ML: diacetyl is the chemical added to popcorn to achieve that fake "buttery" flavor.  As you can imagine, it tastes and smells quite buttery.  But it’s entirely possible to do an ML fermentation and end up with no diacetyl at all (in fact thay’s generally how they turn out, unless you take steps to prevent it).  The ML bacteria produce diacetyl as a byproduct of their fermentation of malic acid to lactic acid, but will consume it unless their fermentation is artificially arrested.  In other words, if you want that buttery flavor, you need to whack the ML bugs with SO2 *before* they finish fermentation.  If you don’t want diacetyl, just make sure that the ML finishes. You’ll get as many answers to the question of when to add ML as people you ask.  I think it’s best to add it just after alcoholic fermentation is complete.  I don’t want to add it any earlier because ML can metabolize sugar to acetic acid, which is not desireable.  I don’t want to wait any longer because I don’t want to let the wine hang out any longer than necessary without proper SO2 levels.  I’ve added it just before the end of alcoholic fermentaiton without negative effects, and I’ve certainly missed the end of alcoholic fermentation by a day or so without worrying about it.  For what it’s worth, the true Burgundian tradition is not SO2 the Pinot barrels until the wine warms up and goes through ML in the Spring/Summer following fermentation.  I’m way too chicken for that. For both reds and whites which will undergo ML, I add small amounts of SO2 at or immediately after crush, like maybe 30-40 ppm.  Tom is our resident Chard expert–you should ask him what he does.  This isn’t enough to prevent a cultured ML, at least at reasonable ( 3.1) pH’s, but satisfies my superstitions and maybe actually helps keep bad yeasties and bugs at bay.  Anyway, since I’ve added SO2, I do cold settle. This year, for the first time, I used K2CO3 (at home) to reduce acidity, and think it worked pretty well.  You might think about that. (Acutally I used it to get the pH high enough that ML would go). Finally, most people believe, I think, that ML reduces the fruity character of wines.  I don’t know if this is really true, or if it is, why it is. Hope this helps. Dave

Response:

This continues a question I had about using malo lactic fermentation to reduce acid in red grapes I grow (Baco Noir and Leon Millot).   References to wines that have undergone ML fermentation mention buttery flavors.  I asked if this flavor was due to diacetyl and the answer was yes.  In beer making diacetyl is usually considered a defect so I was surprised to find that in wines this flavor was considered desirable. RottenGrapes was nice enough to provide web sites that list wines that have had complete ML as well as no ML fermentations.  Chardonnays were the wines listed with ML information.  I bought two of them (ZD-non-ML and Cambria-100% ML).  Both wines tasted completely different.  The non-ML ZD was very fruity~I loved it.  The Cambria (ML) tasted like most Chardonnays I have had over the years.  I’m not a big fan of Chardonnays and I now believe ML fermentation (diacetyl ??) is the reason (NOTE:  having said this I’m finishing the Cambria as I type and it’s a good Chardonnay-I just liked the non-ML wine better). This brings me back to my original quest-a natural method to reduce TA in red grapes.  I just finished pruining my vineyard yesterday and I’m looking forward to a good hot summer here in Kansas.  I plan to let the grapes hang longer than in the past (just say no to pH) and try to let TA fall while the grapes are still on the vine.   However, if acid is still too high I would consider using ML fermentation if the Chardonnay-like flavor can be avoided or minimized.  Common sense says that if I want to avoid diacetyl in my finished red wines I should have ML fermentation going on during the most vigorous phase of fermentation, so the diacetyl is vented with CO2. If true would you add the ML culture at the same time as regular wine yeast? Would you avoid any SO2 addition at time zero? If true, since there is no SO2 protection, would you avoid cold settling before fermentation? Finally,  does anyone have experience with Lallemand 71B-1122 yeast?  I understand this yeast will metabolize 20 to 40% of malic acid.  For those with experience with this yeast would you use it for a big red wine? Thanks for the input. Bill Frazier Olathe, Kansas

Response:

Hi Bill, I’ve been around 71b for some time now. Stone Hill has used it on their reds including Norton for the past 10 years.  It lowers the TA without much adverse effect on the pH.  Like Lum, I don’t believe that yeast species contributes a whole lot to the character of aged wines, so the other qualities of the yeast are incidental. Finally,  does anyone have experience with Lallemand 71B-1122 yeast?  I understand this yeast will metabolize 20 to 40% of malic acid.  For those with experience with this yeast would you use it for a big red wine?

Ed and David have outlined ML quite well already.  I’ll make a suggestion that  you try a few more wines of both ML + and -.  This year we had the chance to do a wide variety of styles with Chardonel including some ML + and -.  The buttery character has not been necessarily related to this bacteria and has showed up in wines that are ML -.  Also the lack of fruit cannot be directly associated with the beast as ML + wines show substancial fruit character.   The Chardonel seems to retain fruit regardless of the secondary fermentation. The other night we did a vertical tasting of our first three vintages of Chardonel.  I favored the 98 by far.  The fruit had moved to the background and some wonderful spices had developed including a fore front of cinnimon and some other lingering allspice and cloves.  Pear and apple were still present but were more difficult to notice.  The oak aroma was virtually non-existant, whereas it was quite substancial when bottled. Tasting this vintage first made the fruity younger vintages less desirable (for me).  The 98 was a 50/50 blend of ML + and -.  The 99 was entirely ML- (lots of pear, apple and orange balanced with oak) and the particular 2000 we served was an entirely ML + version, heavy toast (pineapple, pear and smoke). If you have the capacity in vessels, I’d highly recommend doing a batch of each to determine whether you like the results or not. latron clyde – Hide quoted text — Show quoted text -Thanks for the input. Bill Frazier Olathe, Kansas

Response: