A Few Words On Smoke Taint

USA, California

A Few Words On Smoke Taint

I’ll have more to say about the extent of the smoke taint issue in Californian wines in 2020 when I produce the largescale reports on California Central Coast and Napa Valley later this year. But as offers on the 2020 wines are starting to emerge, I wanted to give consumers a heads-up.

Smoke-tainted 2020 wines are being bottled and sold, even by reputable wineries. However, I wouldn’t be too hard on producers who release wines that have smoke taint. True, they know that their grapes were exposed to smoke, but this is a relatively recent issue, and most winemakers have little experience dealing with it. I have the utmost respect for winemakers who at least try to make the best possible wines under such circumstances. Be that as it may, again and again winemakers have told me that their wines were lab-tested, and the smoke taint compounds numbers were below that lab’s stated detectable thresholds. The problem is that laboratories cannot test for all the taint’s compounds. Most of the time, I can detect what winemakers have been told is undetectable.

Regarding the red varieties, I have tasted smoke tainted 2020 wines from sites in California north of San Luis Obispo, including the major areas of Paso Robles, Sonoma, and Napa Valley. I have also tasted some red wines that have not exhibited any smoke taint characters. This is not to say that these 2020 reds do not have smoke taint because the taint is insidious in its ability to remain masked for a period before emerging. The other consideration is the grape variety. Some grapes seem to absorb more of the offending taint compounds than others. And some varieties wear the aromas and flavors a little better than others. Specifically, Syrah seems to favor a slightly smoky character. This said, I am very sensitive to smoke taint compounds and am not a fan even in the slightest. I particularly dislike the ashy smell and aftertaste. Smoke taint also seems to render tannins with a certain rusticity/hardness that I do not enjoy. But I have tasted smoke-tainted wines with consumers (not experts) who do not notice/mind the character, which is worth considering.

Not all 2020 Californian wines have smoke taint. I haven’t yet tasted any 2020 white wines that have smoke taint. Nor do I expect to, since most white grapes were harvested before the smoke became a real issue in most areas. Also, white grapes tend to have little or no skin contact, and late-season smoke mainly affects the skin.

Some red grapes were harvested before or soon after the major fires broke out. And some areas of California had little or no exposure to smoke from wildfires before harvest. Areas of California where I have tasted and NOT found any wines that are smoke tainted are those south of San Luis Obispo, including Arroyo Grande, Santa Maria, Los Alamos, Sta. Rita Hills, and other regions of Santa Barbara County. It thus far appears these areas were far enough away from the Monterey County wildfires to the north to get away unscathed, but if I spot any smoke-tainted wines, I will be sure to let readers know. The best advice when purchasing 2020 wines from California is to take some expert advice. 

What is Smoke Taint?

The following is an excerpt from an article I wrote about Smoke Taint a few years ago. I hope readers find it useful.

Whenever smoke comes into contact with developing grapes for any period of time, there is a risk that the grapes will carry smoke taint and impart this in the wine made from them. Understanding this risk can help wine buyers make informed investment decisions when confronted with seemingly good offers for possibly tainted wines.

A taint in wine can be defined as a foreign volatile compound or group of compounds affecting the experience of the wine, including its smell, taste and/or texture. In other words, these compounds are not directly derived from grapes nor intentional winemaking operations. Perhaps the most common example of a taint in wine is TCA or 2, 4, 6, Trichloroanisole, better known as cork taint, which can ruin even the rarest and most expensive wines without the buyer being aware until they open the bottle. 

Smoke taint occurs when developing grapes are exposed to the smoke from wildfires for any period of time. A number of factors will determine the level of impact the smoke will have on the berries, including the state of berry development during the episode, the duration of exposure, and the concentration of smoke. 

While solid particles such as ash can be rinsed off the berries, the compounds responsible for smoke taint are far more insidious. There are several ways for these compounds to enter the berry, but the skin is most commonly and detrimentally impacted. For this reason, it is mainly red/black grapes that are affected by smoke taint since most white wines are made with very little or no skin contact. Once smoke-related volatile compounds have infiltrated the skins of berries, they are impossible to remove without rigorous filtration methods (e.g., reverse osmosis) that strip the wine of character and complexity. Wines thus treated possess an aromatically dulled, flat, and hollowed character.

Once in the skins of berries, the volatile compounds from smoke contact bind with sugars, forming more stable compounds known as glycosides. Glycosides are non-volatile, meaning that they can’t be smelled or tasted. Glycosides are, however, somewhat unstable. Contact with acids or enzymes can break the bond, and the smoke compound becomes detectable again. This bond can become undone during fermentation, when a wine has been in bottle over a period of time, or when the wine comes in contact with enzyme-containing saliva. Thus, smoke taint can exist masked in wine for a period of time before it becomes apparent.

Like cork taint, a wine can suffer from a minor, barely noticeable case of smoke taint, or it can be screamingly obvious. The one similar element across all smoke-tainted wines is that they possess aroma and flavor compounds that generally would not come from grapes and/or permitted wine practices such as oak aging, especially not at such elevated levels. So, for consumers with considerable experience in tasting and drinking wine, the taint will come across as an unusual charry, creosol, medicinal, or ashtray-like character that shouldn’t be there. This said, some smoke-taint compounds can be very similar to oak-aging compounds, especially if a wine has been aged in oak with a high toast level. 

Indeed, there are wines best described using smoke-related terms such as woodsmoke, chargrill, smoked meats, or just plain smoky. Furthermore, some grape varieties, such as Syrah/Shiraz, naturally contain volatile phenols derived from the grape and winemaking that are indeed quite smoky. Some of these compounds are even shared with smoke-taint markers. Many Syrahs are thus quite “smoky” without possessing any smoke taint, and many consumers love them. 

At very low levels, smoke taint probably isn’t so bad, depending on personal preferences and tastes. But above the detection thresholds, that smoky, charry, or ashtray-like smell and taste can become anything from distracting to distasteful. In worst cases, this character can be particularly acrid, with an unpleasant, persistent aftertaste, lingering long after all the fruit and winemaking flavors have disappeared. It also seems to make tannins appear harder and more astringent, equating to what is euphemistically termed a rustic character. 

As we experience more and more wildfires in wine-growing regions during the summer and autumn, smoke taint is a quality factor of increasing importance to the wine industry and consumers. Affected wineries are forced to make tough financial decisions. Options include:

Should you consider buying a wine from a region/vintage that has been exposed to smoke? The answer is yes, but with great caution.

A little research will be required to understand the risk. Wine regions are vast, and during any wildfire episode, there will usually be pockets of vineyard land that are not exposed to smoke. While wineries may claim that their vineyards were not impacted or that their berries tested clean/below detection levels for smoke taint, serious buyers should only trust an unbiased, third-party source of information based on tasting before buying. Another investment consideration is the question mark over the quality/consistency of the vintage. A possibly smoke-impacted vintage will no doubt be less sought-after than a consistently great vintage and will therefore be of lesser value on the secondary market. If the buyer is purely seeking wines for their own consumption, then there could be some clean, good-value wine buys during a smoke-impacted vintage. However, as with most things in life, if a bargain looks too good to be true, it’s probably not a bargain.


Article by Lisa Perrotti-Brown MW