Is it reduction?
Is it sulfur?
Is is both?
Might it be terroir (I’m dubious…)?
What other regions display it?
Alex R.
When people use the word “reduction” they are really using it (or should be) as a broad term to describe some kind of sulfur compound(s). The distinct matchstick note (I believe) is the most “direct” form of sulfur - SO2 (sulfur dioxide), which is the compound that is added to wine for preservation. Wines can develop other sulfur compounds, that have different aromas (like skunk, coffee, rubber tire, rotten egg, etc).
Here’s a short article that talks a little about this, although I think they are actually wrong in attributing the matchstick aroma to disulfides, which tend to lean to garlic/onion/rubber aromas.
It’s both, because reduction is based on sulfur-containing compounds like hydrogen sulfide (H2S) and mercaptans. When talking about sulfur, people often mix up sulfide with sulfite. Sulfite refers to forms of SO2, which is added to wine as an anti-oxidant, anti-microbial agent, and a tiny bit is present in wine even if it’s not added. Sulfide and sulfite aromas are completely different. Sulfide is anywhere from rotten egg, tire rubber, and heavily charred wood to onions and garlic. There are many more descriptors for sulfide.
Sulfite is more of a sensation than an aroma. In a young German Riesling, it’s easy to pick out sulfite, but if you’re not used to looking for it, you might not notice it. My first encounter with sulfite was kind of an accident. I was looking in a winery bucket to see if it was clean, but I didn’t realize the person who used it before had mixed up some KMBS (potassium meta bisulfite–a common form of SO2 used in wineries) in that bucket. I breathed in more sulfite than anyone should, and had a 30 minute asthma attack. I was 27 at the time and had never experienced asthma in my life. I’m not at all allergic to sulfites, but I breathed in so much at that one moment, it would’ve given anyone an asthma attack.
In previewing my response, I saw Alan’s reply (but I didn’t read the article) and want to add this. Yes, it’s true that right at the moment when you strike a match, you can smell SO2, or sulfite. But it’s a very fleeting moment. It’s amazing that matchstick aroma has been used as the sulfite descriptor for so long. In my opinion, reduction in white Burgundies has everything to do with sulfide, and very little to do with sulfite. Yes, pHs in Burgundy are very low, and sulfite should be apparent when the wines are young. However, they stick out so much more in young German Rieslings, just based on the even lower pH. I doubt most people notice the sulfite in young white Burgundies. I believe what people are smelling are sulfides.
Ed, are you distinguishing sulfides from disulfides, or lumping them together?
I confess to being a little confused as well when people refer to matchstick. On some young German Rieslings, and quite a few young white Burgs in recent years, I do think I pick up SO2 notes early on, because those wines have so much SO2 added. I think it might be important to distinguish between very young wines closer to bottling (where SO2 seems more likely to be present at a concentration high enough to detect), and older wines where sulfides, disulfides, and mercaptans have had a chance to form. What do you think?
Alan, yes, definitely putting all the sulfides together.
German wines show so much SO2 when they’re young because their pHs are so low, and the lower the pH, the higher percentage the sulfite will actually be molecular SO2. A free SO2 of 10 ppm SO2 in a German Riesling at pH 2.95 will show so much more SO2 in the nose after bottling compared with a California Pinot with 30 ppm free SO2 and a pH of 3.65. You would probably need 75 ppm free SO2 or higher in that California PN to show as much SO2 (sulfite) in the nose as that Riesling, and no one would bottle with that much free SO2.
Thanks, Ed, for your comments. I’ve been posting on this question off and on for a few years because I’ve felt that lots of folks, even pros and serious afficiandos who should know better, mistakenly attribute smells from sulfides to SO2. characteristics in reductively made white burgs (coffee, creosote, matchstick, smoke, etc) repeatedly is blamed on heavy sulfuring, which in most all cases it is not, at least as far as I can tell. (Or it’s blamed on heavily charred barrels, which may be another mis-attribution).
So it’s not so much the amount of SO2 addition, but the fact the the low pH pushes the equilibrium farther toward the undissociated H2SO3 (and therefore a higher concentration of SO2). OK. I still think when most people say matchstick, this is what they’re detecting, but maybe not.
I should have explained that I asked the question because this “matchstick” quality is viewed indulgently or even favorably by many tasters.
I was wondering: but isn’t this a flaw?
I might add that the quality is also present in older wines, and I doubt that will disappear with aeration and/or decanting.
Best regards,
Alex R.
Jancis Robinson
An increasing proportion of whites are high in acidity, have no trace of the toastiness of oak and have the flinty smell of recently struck matches
These sulphide notes are associated with “reductive” winemaking, in which wines are protected from oxygen during ageing.
I wonder how many younger people have never struck a match ?
Yes, it can come from SO2 directly and/or H2S (hydrogen sulfide), which is the first form of what we call “reduction”. It’s more likely the latter if you are smelling the aroma strongly. SO2, for me, is more of a physical sensation (stinging or burning in the nostrils; I am very sensitive), but it can also have that aroma a bit.
I’m a little puzzled as to why some people seem to prize these winemaking-related aromas. I read quite a few notes that mention them prominently as if it’s a good thing. There are certain highly esteemed domaines in Burgundy which produce wines in a highly reductive style. Those wines, when young, often show these sulfur-related aromas so strongly that they can, to me, overpower sense of place. With young wines that show this characteristic, I prefer to drink them after extended aeration to hopefully get those things to dissipate.
I don’t really see how it could be H2S, that’s such a distinctive smell that everyone knows. And it shouldn’t be a byproduct of striking a match - that’s SO2.
I confess that this can all be pretty confusing, even for someone trained in chemistry. Wine is a complex mixture, and ferreting out the sources of complex low level aromas isn’t easy.
Good technical article on sulfur compounds in wine.
Ed, I’ve also worked around bisulfite compounds and sulfurous acid. The odor is definitely more of a sensation…like being harshly grabbed by the nose with a finger up each nostril…the subsequent asthma/breathing response is unpleasant, to say the least. It’s been 30+ years and I remember it well.
RT