Wine Tech Question: Where does Butter Flavor Come From if no Malolactic Fermentation?

Oenophiles,

Time to pick your brains for technical knowledge. Chateau Montelena has been on my mind since an awesome 2008 Chardonnay of theirs I tasted recently at Alo restaurant. My specific note was that it was a perfect balance of Burgundy delicacy and bold California fruit flavor. I particularly noted the light butteriness and oaking that served as a complement to the wine’s balance rather than the heavy use of both which is often designed to cover up flaws in the wine which I was warned about at my first ever California Wine Fair in Toronto.

Well, in other threads it was posted and verified later by me using this global interconnected data thingy we’re all hooked up to and on that they do indeed use a mere 8% new oak and zero malolactic on their Chardonnay. Well, the mere 8% new oak explains the light and perfectly balanced use of oak as a spice in their Chardonnay… but what about the complementary light butter flavor?

I have always been taught that malolactic is what is responsible for that buttery flavor and texture in wine. So if none is done, how can it be present in the Montelena Chardonnay? Is this because there is some natural malolactic occuring anyway in the winemaking process? A byproduct of the sparing use of new oak?

I must admit I’m very intrigued here. I have avoided California wines in general and Chardonnay in particular because of what I feel is heavy oaking and malolactic resulting in pencil and oil shakes instead of wine, but the Robert Biali Rocky Ridge Zinfandel and now the Chateau Montelena Chardonnay are really game changers for me here.

Anyway, feel free to chime in with your expertise if you have a knowledgeable answer for me or your psychological evaluation if you think I’m crazy because there is no actual butteriness to the Montelena Chardonnay and I’m imagining things. In pre-emptive defense to the latter, I have had unoaked Chardonnay before and it honestly tastes nothing like the Montelena. It’s like bitter unripe apples to me. The Montelena tastes to me like fresh apples that have been lightly dressed in sweet butter in comparison.

I am not an expert but malolactic fermentation is the conversion of malic acid to lactic acid. Lactic acid is the type of acid in milk or butter. Hence the buttery flavor.

Oak should be giving toasty flavors (depending on the char) or vanilla flavors. Not sure why oak or absence thereof would impact butter flavors.

You might want to try something like this. http://www.wineenthusiast.com/wine-essence-kit.asp

Hmm - well my best guess is that the perception of light butter may be some early maturity in the wine more along the lines of honey/honeycomb sweetness. Battonage can also add some texture as well in absence of malo. (No idea if they stir or age on lees). Often in warmer microclimes, malo is blocked to keep the wines more vibrant by retaining the malic acid which often gives a green apple character. Keep in mind that grapes from different sites/climates will have varying levels of malic acid and in cooler sites, blocking malo could give a wine a more overwhelming tart green apple character.

This is wrong. Lactic acid doesn’t taste buttery. Diacetyl does. Diacetyl is mostly created through the consumption of citric acid during malolactic. But it can also be created during primary / alcoholic fermentation, which is why wines that don’t go through malo can taste buttery (this is, IMO, really common for Jura whites).

Tran - what David said.

It is never so simple as American Chard = oaky, non-American = non-oaky.

Nothing in wine is that simple and people should stop trying to make things too black and white. Anyhow, the diacetyl can indeed come from the yeast and the yeast strain can matter as well. Also when we talk about what kinds of sensory experiences we’re having, it’s important to keep in mind that our brain is looking for patterns and it takes suggestions as well. So if we have something that somehow reminds us of something maybe bread-like, perhaps from lees, and gives us a hint of something saline and/or toasty, albeit ever so slightly, our brain might kind of interpret that as kind of buttery at that moment. The concentrations of things matter, as do the memories they evoke.

And here’s something else to consider, from the journal of Applied and Environmental Microbiology:

The final diacetyl concentration in the wine was also dependent on the concentration of SO2. Diacetyl combines rather strongly with SO2(Kf = 7.2 × 103M−1 in 0.1 M malate buffer [pH 3.5] at 30°C). The reaction is exothermic and reversible. If the concentration of SO2 decreases during storage of the wine, the diacetyl concentration increases again.

I agree that it could be diacetyl from alcoholic fermentation, but I suspect the real answer here is that the oak is giving a subtle buttery aroma. It can be tough to distinguish between oak and MLF in some cases.

David is correct.

I suspect another reason, perhaps not your case, is that a lot of people use the term “buttery” too loosely. I’ve heard many people describe a wine as a “buttery Chard” or use the term “buttery” in tasting notes when there isn’t any obvious diacetyl notes, but instead the wine is just fruit-forward and oaky. In other words, “buttery” has become a term to describe a style, as opposed to a specific note.

Diacetyl does taste buttery. Nearly all the diacetyl in wine is produced by ML bacteria during the conversion of malic acid to lactic acid (generally it’s Oenococcus Oeni, there are a couple of others that can do the job safely, but they’re uncommon).

However, once all the malic has been consumed, the ml bacteria will eliminate the diacetyl (and hence it’s butteryness) by consuming the diacetyl and turning it into another (I forget the name) compound that has very very little taste/other impact on wine. So, if you do want that diacetyl buttery flavor, you need to be on top of things and time the sulfur addition properly (which will kill the ML Bacteria)…i.e. after all the malic is consumed but before much of the diacetyl has been. This depends on having a healthy population of ML bacteria when the malic is gone…and remain healthy long enough to consume the diacetyl. The levels of alcohol (too high), pH (low), sulfur (high), va (high) and a few other esoteric (tho at times important when your ML is stuck!) things are all stress factors for ML bacteria and will shorten their life. But, you can buy ML bacteria that push each of these boundries pretty far…and even some of them in combination pretty far (high alcohol and low ph for example, which surprised me). Fortunately I haven’t had to buy any of these, except one for a low pH chard (below 3.1 ph) last year when I didn’t want to take any chances (the TA, prior to ML, was above 9, so getting through ML was important).

Some, but very little (compared to malic to lactic), diacetyl can be produced during the primary/alcoholic fermentation. But not enough to be concerned about…again, depending on the yeast. If the wine went through ML then the the ML bacteria would consume this diacetyl (as descibed above) in all likelihood.

ML bacteria can also produce diacetyl from citric acid…however ML bacteria consuming citric also produces acetic acid (aka va, i.e. the main component in vinegar). Fortunately wine rarely has any significant amount of citric acid in it. Tho, if there is, there are a couple of ML bacteria out there that have the citric function blocked (i.e. they can’t consume citric)…tho one has a ~12% alcohol limit, and the other (by Chr Hansen) is a bit pricey.

The main source of buttery flavor, other than diacetyl, would most likely be yeast lees. Different yeast strains have different contributions to wine…some, CY3079 (a yeast from Burgundy common used on Chardonnay) makes wine taste buttery (in a different way than diacetyl, but both are still buttery). Also, Yeast lees, if they have been stirred in the wine, can sometimes make the wine taste more oaky than it really is.

My impression of American Oak is that it imparts a cinnamon taste. I am probably wrong though.

And thank you Eric.

My guess (as mentioned by a few others above) would be battonage stirring up a wine aging sur lie.

It could but again, it’s not always that easy to distinguish American vs French oak.

There are a lot of variables, e.g. whether the wood is hand split or sawn, and whether it’s dried in kilns or in air, what sort of heat you use to bend the staves - steam, boiling water, natural gas, wood fire, then whether or not you toast it and how much once it’s formed into a barrel, etc.

And there are various sources of both French and American oak - in France for example, Limousin is warmer than say, Tronçais so the trees have a looser grain. And then there are different types of oak in those French forests as well and when you’re talking about American oak, you’re talking about a much larger region than France, so there are many differences in American oak too.

There’s Quercus robur, which is also known as English oak, but there’s also Quercus Petraea, which is known as Cornish oak or Irish oak and which is usually shorter but has a tighter grain. And both of those are also found in America.

If you ever get a chance, it’s very instructive to taste the same wine side by side done in various barrels using different oaks and different treatments of the wood.