Category Archives: Wine Tasting

Vintage Musings III: complexity and when to pick

We all love wine, different taste of wine. Is it safe to assume most people understand that a little bit of character from Brettanomyces enhances the complexity of a wine?

Sure everyone’s threshold is slightly different, but when 4-ethylphenol or 4-ethylguaiacol hover around the threshold an already wonderful wine can become sublime and an ordinary wine compelling. In other words, flavor compounds generally recognized as a fault can often enhance and augment a wine helping the whole be greater than the sum of the parts. Of course it is a risky line to walk, but I think most would agree with this premise.

It is with this in mind that I follow-up the recent post regarding picking by flavors. If it is true that flavor compounds generally recognized as a fault can often enhance and augment a wine than is it true for methoxypyrazine specifically? While working with Merlot and Cabernet Sauvignon this compound is something we often ponder since it contributes to the relatively unsavory bell pepper aroma.

Studies (Allen et. al. (1991); Lacey et. al.(1991)) with white wine have shown that when methoxypyrazine was added to wine that otherwise had none, concentrations as low as 1 part per trillion significantly influenced the aroma of a methoxypyrazine-free white wine (emphasis mine) but was not necessarily perceived as pyrazine (bell pepper, chili, ect.) per se. In fact the threshold in this study was determined to be around 8 ppt in white wine. Typically aromas such as these have even higher thresholds in red wine. Why bring this up? Well the problem with scientific studies is that they understandably avoid more subjective conclusions regarding perceived quality and limit themselves to analytical quantification. What interests me is that the compound contributed to the overall aroma as low as 1 ppt, but while scores for veggie increased with increasing concentrations of pyrazine, there was no significant difference between 1, 2, 4, and 6 ppt. It was not until 8 ppt that the tasters effectively said, Whoa, now that is different.

Therefore since the tasters do not indicate whether or not they liked the aroma, I am free to use this study amongst other corroborating evidence to make my own speculation about aroma contribution. This is a 3 paragraph intro to get to this point: at these low levels the contribution to the aroma certainly could have been positive contribution to complexity, to interest, to intrigue in the wine.

Don’t let their term used to train the tasters – veggie – throw you off track. Why shouldn’t the pyrazine compounds improve and complex the aromas and flavors of the wine that would otherwise have none? Indeed, Allen has said elsewhere in regards to Sauvignon blanc: [pyrazine] concentration in Sauvignon blanc wines is typically 5-30 ng/L. Below 5-10 ng/L, the aroma is subdued; at 15-20 ng/L it provides an aroma that is distinctive, characteristic of the grape variety, and frequently balanced with other flavor components in the wine; at only 30 ng/L it begins to be rank and overpowering. Too little of this compound leads to an undistinguished wine, but too much gives one that is unbalanced (emphasis mine).

Vintage Musings IV: getting a picture

The blocks that generally require such tractor passes in order of frequency are the Syrah blocks followed by the young Chardonnay (representing 2 of 4)and then the young Merlot (representing 2 of 3).

After tasting all lots I continue to be convinced that indeed the blocks just mentioned improved the most that year.

So what of the other old vine blocks (Chard, Merlot, and Cab.)? Well, they are tremendous but that is par for the course. I think it is typical for the exact reason that 1) they already have low vigor and generally require 0 (sometimes

1) hedging pass to address excessive shoot growth in normal years. Of course there are other factors involved here that make the site wonderful, but what I have outlined above consistently produces wines of weight and concentration that is gained from methods other than extended ripening.

2) At least for white wine it is generally accepted that early water stress (or severe water stress in general for that matter) is less important for improving quality that it is in reds. Interestingly, the early stress not only impacted canopy vigor, but also clearly impacted fruit and cluster size. Most obviously in Chardonnay.

But as noted, even though cluster size was down 50% in Chardonnay, I would not say quality was up 50% or even close to that. Another indication that yield is not so simply linked with quality but how you get that yield probably is. And this year lower vigor and lower yield as a result of low water availability early has clearly positively impacted quality in the blocks where vigor is generally the greatest.

OK, so the whole post is a general simplifications but the main point is that quality across the board is up and the vintage devigorated blocks that need devigoration the most and this has resulted in serious quality gains in those blocks. The message is clear: buy your futures now.

Vit Practices: Color and Cab

Here is the bottom line on this fairly well done study: Increasing your hang time will impact your color. However, there was no difference between 1 and 2 weeks after normal harvest dates.

Although the authors try to sell this as a study about wine quality, no sensory work was performed and they really only looked at color. Nevertheless, slightly riper grapes seemed to have a little better color stability after 18 months.

Reading this article after another recent gem on light and color highlights the possibility that looking at total phenols, or phenols in general is largely deficient in determining quality (an opinion I am developing). The grapes used here may have had more color later, but what about vegetal, peppery, or fruity flavors? Was there a difference at all in characteristics such as these? It seems to me most of us would take the diminished color at ripening stage 1 (about 22.5 Brix) and subsequent lower alcohol if we were confident the flavors were delectable and weren’t going to get any better. But do they get better? Or just stylistically different? If you want a summary of study details see below.

Perez-Magarino, S et. al: J. Agric. Food Chem. 2004, 52, 1181-1189

Tinto Fino (TF) and Cabernet Sauvignon (CS) were used to assess the effect of the degree of grape ripening primarily on wine color. Color changes during ageing of each treatment was also examined. The levels of flavanols, anthocyanins, and derivatives of both types of compounds, were assayed immediately after fermentation and at different times during aging in American oak barrels and in the bottle.

The ripening stages were approximately as follows:

1)conventional’ 22.5 Brix, pH 3.36, TA 7.76 (CS) ; 2) 1 week after (23.6 Brix); and 3) 2 weeks after (~24.2).

Fermentation between 25 and 28 °C with 40 mg/L SO2. The maceration time was ~ 14 days. Pressed at ~ <3 g/L sugar, transferred into barrels where malolactic fermentation and wood aging were carried out.

The results showed that “maturity date” or “ripening stages” effects were detected, but these are different for each individual component as well as for each of the two grape varieties studied.

In general, the dimer and trimer flavan-3-ol derivatives reached higher levels in the unaged wine made from the grapes collected on the later harvest dates which indicated that the degree of flavanol polymerization increased with the degree of grape ripening. However, this was only true in the CS. The TF had its peak in the middle ripening stage. There seemed to be only small differences between ripening stage 2 and 3, and certain compounds were even statistically higher in stage 2 than in stage 3. No difference in total phenols existed between stages 2) and 3).

WINE AGEING: “No clear trends with grape ripening were observed. In fact, the CS wines with the highest color intensity values were the wines made from the grapes collected on the 2nd harvest date.” The wines made from more mature grapes had higher levels of flavanols and their derivatives.

The free anthocyanin content decreased sharply during aging, the greatest losses taking place in the first months of aging. After 18 months of ageing, any initial differences in anthocyanins and its derivatives (termed ‘new pigments’) due to ripening stage were virtually erased. However, color intensity differences were maintained after 18 months and in all cases the percentage of blue increased as ‘new pigments’ increased (i.e. anthocyanin products that are not antho-tannin complexes). Wines made from ripening 2) 3) showed higher levels in these ‘new pigments’, in both TF and CS wines.

Summarizing: delaying harvest date between 1 and 2 weeks produced grapes with greater color intensity and a higher percentage of blue pigment. This increase in anthocyanin derivative levels contributes to color stability by maintaining color intensity and increasing the blue component.

Additionally, the results showed that the amount of time the grapes are left on the vines may need to be limited, because wines made from the grapes collected on the 3rd harvest date did not exhibit better color quality characteristics than the wines made from the grapes collected on the 2nd harvest date.