Does Smoke Taint Return?

This is the subject of much debate and speculation, mostly due to the fact that it is relatively poorly understood. The smoke taint character will not return after our process due to our improved targeting of the offensive spectrum of volatile phenols.  Australian research showing that treated wines had smoke taint sensory characteristics later return was not conducted with our method.

 

There are important precautions to take to prevent complicating factors from intervening.

 

PRECURSORS

The measurable levels of guaiacol and 4-methylguaiacol vary widely over the course of the life a wine. Fortunately they are markers only and not active in the offensive characters. It does not appear that volatile phenols can evolve from precursors or related compounds.

 

BLENDING

Some volatile phenols are HIGHLY synergistic.  We have had customers with two successfully treated batches (no sensory presence) subsequently decide to blend them together. Next thing you know, the smoke taint was faintly perceptible again.  Synergy.


Also, treated smoke tainted wine blended with non-smoke tainted wine has been known to occasionally show subsequent smoke taint characters.

 

All blending of treated, originally smoke-tainted wines should be done with great care. Assemble lab blends and hold for sensory analysis for a minimum of two weeks before making the blend.

 

AGING

Clearly wines change over time.  Certain characters come and go relative to others. This is why we age wine of course--both before and after bottling.  No doubt, very subtle characters can come in and out tune. Including smoke taint potentially.

 

MICROBES

You may not want to admit this, but just about every wine spoilage microbe exists in your winery in some form. You don't maintain operating room sterility, and even if you did, you bring in grapes every fall, which are quite unsterile.  These microbes are not usually a problem, because you maintain good sanitation, and, most importantly, you maintain good pH, SO2 and other defensive measures.

 

However, it is generally true also that very low levels of microbial activity are going on in your cellar right now.  And it probably will be so low that you won't notice and won't care.  The 4ep on your zinfandel went from 54 ng/ml to 72 ng/ml? Not even the most sensitive nose can detect that.  We are particularly concerned here with Dekkera and Brettanomyces, as their metabolites are very closely related to the volatile phenols associated with smoke taint.

 

The sensory threshold for 4-ethylphenol is about 400 ppb or thereabouts.  4-ethylphenol is also found in brett-free smoke tainted wine.   The sensory thresholds for smoke taint related volatile phenols are somewhere around 5-20 ppb.  Now also consider that Brettanomyces activity produces a whole host of minor aromatic phenols, not only 4-ep and 4-eg.

 

Conclusion: It doesn't take perceivable levels of Brett or Dekkera metabolites to potentially aggravate smoke taint.

 
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