Recently I have had two wines with this profile. A Copain PN and a Rivers Marie cab. I find this flaw more common than it should be. Usually in cheaper cabs and with the Copain it is the first time I find it in a PN. From what little I know, it comes from bacteria producing lactic acid. i.e dirty tanks or barrels. Does the smell and taste dissapear with time? Anyone else have any insights?
Lactic acid is a common misconception (which I once held). There was a long discussion between people who know far more chemistry than I do here:
The note is a bit odd and I don’t know what to make of it, but based upon what I have been told the explanation is 180 degrees off. First off all, at least two winemakers have told me that the lactic acid flavor component, which is sometimes also perceived as grapefruit, is from incomplete malolactic fermentation in red wine. Second, despite common misunderstandings, the buttery flavor, which is different from oaky vanilla, is a function of the “battonage” and lees and the barrel aging process. I have been told that stirring the lees during fermentation can absorb the chemical that is otherwise naturally created and thus reduce the buttery flavor, ands that the amount of stirring in initial fermentation can affect that as well. But what do I know? I just drink the stuff.
PS - Love the M-C Scherube. I brought one to Leo’s a few years ago and he went wild over it. He asked who brought it and when I said it was mine, he didn’t believe I owned wines like that.
I don’t equate sour milk, lactic and buttery at all. Buttery, as in movie popcorn butter, is often ascribed to diacetyl produced during fermentation, but more details than that I don’t know. Sour milk is nauseatingly disgusting. Lactic doesn’t carry such negative connotations for me. Should it?
I think that differences in terminology make this topic more confusing. At least when I use the term “lactic,” I’m referring to the smell of milk that is just starting to sour and a certain corresponding sourness on the palate. I find it most often in northern Rhones and attribute it (perhaps in error) to brett, as I think I’ve always found other more typical brett indicators when I find the character that I call lactic.
Having worked in a movie theater concession stand in my youth, I know diacetyl, and will generally refer to it in wine as either diacetyl or butter, with the latter more likely when oaky vanilla and smooth, fat texture from lower acidity often found in California chards is present.
I don’t know what lactic acid standing alone smells like, so I use the descriptor of “lactic” and not “lactic acid” as I’m not sure that the character I’m describing is attributable to lactic acid.
The lactic acid reference came out after i googled about it. It has nothing yo do with the buttery tones in chardonnay. One source attributes the sour milk smell to excessive malolactic fermentation. Regardless, I find this smell and taste, to various degrees, quite often and I am surprised more people have not noticed.
Sounds like a lactobacillus issue- a common bacterial issue with wine. Same thing that turns milk into yogurt. Like most microbial buggers (yeasts like brettanomyces, dekkera, zygosach, etc. and other bacteria like pediococcus) the populations can grow in the bottle if there is substrate for it to feed on (usually sugar or sometimes malic acid).
Great link Wes. So diacetyl can be one of the many byproducts of lactic acid bacteria spoilage. I don’t associate “lactic” as a descriptor with any of the spoilage aromas listed in that link. I think of it as a milk/fresh yogurt aroma. I wonder what it means to others?
Your Yogurt is my sour milk.
BTW the wines were a 2011 Copain Pinot Noir Wentzel Vineyard and a 2012 Rivers-Marie Cabernet Sauvignon Napa Valley. The cabernet had a more subtle tone but it was there nevertheless. The Copain was a mess beyond the sour milk. Bought at the winery too.