December 11, 2015
Vinification d’un vin rouge sans dioxide de soufre by Vincent Chassignol (Éditions universitaires européenes, 2015)
This book is a BIG disappointment, particularly given its $53.37 price tag (CAD$ from Amazon.ca) for some 50+ pages of less-than-substantive content. It’s basically a student’s memoirs of his 6-month internship at a Châteauneuf-du-Pape estate trying to make a wine without the need for sulfur dioxide (SO2).
But I’m being very critical here for more important reasons.
The title translates to “The making of a red wine without sulfur dioxide.” Half the book discusses anything but making red wine. And if you are writing about the use, or lack, of SO2, you’d think one would proofread SO2 figures with a microscope. In their white winemaking, “after tasting (wine samples), the wine is lightly sulfited at a rate of 3.5 g/L [sic]. That’s would be 3500 mg/L; they meant 3.5 g/hL. Ok, it can be forgiven.
In the usual red winemaking, before this experiment of eliminating the use of SO2, they add 5 g/hL of SO2 at crush followed by 4 g/hL after completion of the MLF.
But now we’re getting into the experiment in making that no-SO2 red. We’re at page 31, well, really page 37 after some theory on SO2 chemistry. The conclusion is coming up on page 48, really the last page of the book.
The chapter about the experiment is prefaced by the disclaimer that “we will see that that it is very difficult to completely eliminate SO2 use without losing quality.”
The experiment is carried out in 3 lots for comparative purposes:
Lot 1 – no SO2 added at crush
Lot 2 – no SO2 added at crush; but with enological tannins added
Lot 3 – made by conventional methods by adding SO2 at crush and following MLF
Lot 3 had significantly higher color intensity and higher total phenol content (TPC) of the 3 lots. TPC is an important indicator of a wine’s oxygen-scavenging potential, and therefore its aging potential. Lot 2 (with added enological tannins) had higher color intensity and TPC than Lot 1.
Surprisingly, Lot 3 had higher volatile acidity (VA). Even the author admits not understanding what could have caused this in a wine protected by SO2. But he concludes that Lot 2 had lower VA than Lot 1 and that, therefore, the enological tannins had a protective effect against oxidation. First, the error on VA measurements is greater than the noted differences, and so that conclusion cannot hold. Second, based on that argument, why wouldn’t Lot 3 be showing lower VA since it had the highest TPC and SO2?
In a taste test, Lot 3 (pH 3.70) was noted to have detectable SO2 although it had less than 10 mg/L of free SO2 as did Lots 1 and 2, both with a pH around 3.6. Even at those pH values, that little free SO2 cannot be detected even by the most skilled tasters. Total SO2 in Lot 3 was still only 29 mg/L; Lots 1 and 2 were below the 15 mg/L measurement threshold. Given the relatively similar pH and free SO2, one has to wonder about how the sulfite additions were performed and how the taste test was conducted, but we know it was not done double-blind.
Lot 1 had significant oxidation aromas and smelled of cooked or jammy fruit. Lot 2 also had oxidation aromas, but much less so. Overall the aromas seemed very positive in Lot 2 although the mouthfeel was astringent and that it detracted from the overall balance of the wine, but that’s to be expected in tasting the wine so soon after fermentation.
My overall impression was that this book would offer some new insights on making red wine by reducing or eliminating SO2 altogether. Unfortunately, the author’s experiment proves otherwise. The bigger missed opportunity was in not making use of complimentary techniques to SO2 reduction/elimination, such aging on the lees, barrel aging, micro-ox, etc. Instead he focused on hygiene and the need to be extra vigilant and thorough with sanitization, but all winemaking implements – or should implement – very strict hygiene protocols.
And so, there was nothing new here and it certainly did not make a case supporting making red wine by reducing the use of sulfite. A strong case could have been made with a much more holistic approach then simply taking sulfite out of the equation.