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Why Is Hangtime Such An Issue?

by David on June 30, 2009

If “hangtime” or “extended hangtime” is a new term to you, it’s because it hasn’t been in use very long. It refers literally to the amount of time we allow the grapes to hang on the vine before we harvest. It’s become an issue because there’s been a recent trend toward leaving the grapes on the vine longer than we did in the past. It’s all a natural part of our evolution and learning curve here in California.

We’ve been making wine in California since Father Junipero Serra planted the first grapevine here in the late 1700s. There was a thriving industry here at the turn of the 20th century. However, prohibition was so disruptive that when repeal came around in 1933 it was almost like starting over again. It’s so easy to make bad wine that we became very analytically oriented and directed our efforts more toward suppressing fault than heightening the good. We had the equivalent of recipes from the University for making white vs. red wine and this is probably where California got its reputation for mediocrity.

Picking grapes by the sugar content

One part of the recipe was to pick our grapes according to the percentage of sugar, which may not be added in California. Here’s how it works: during fermentation, we can predict that 50-60% of the sugar will convert to alcohol, depending on the yeast (the rest converts to heat and carbon-dioxide gas). In the 1960s and 70s a common standard for red wine grapes was to harvest at 24 degrees brix, roughly 24% sugar, to end up at about 12.5 % alcohol. In some cases wineries even paid growers bonuses for delivering their grapes at a particular sugar.

As long as the weather is warm and dry the sugar goes up. Naturally, the growers wanted to get their grapes in before they risked rain damage, so these bonuses were incentives to keep them from picking too early.

Harvesting by flavor

Later on, as it occurred to winemakers that there might be more to ripeness than just sugar, we started hearing the phrase “hang-time”. They started emphasizing flavor development and seed maturity as they continued to monitor the sugar.

Geoff Testing Sugar in LabThis is where things started to get complicated. In warm weather sometimes the sugar runs ahead of the flavor maturity. Working under the theory that if they don’t wait long enough the wine will have green, vegetal character and harsh tannins, winemakers became more inclined to allow the sugar to climb while they waited for what is sometimes called physiological maturity – mature flavors, crunchy grapeseeds and dry, brown stems.

Growers take a pay cut

Two significant issues were spawned by the trend toward extended hang time and higher sugars. One is financial. Most growers are paid by the ton. A study on Cabernet was conducted by Ed Weber, the Napa County viticulture advisor for the University of California Cooperative Extension. He concluded that for each degree of sugar or brix over 26, a Cabernet grower’s tonnage goes down by about 5% due to dehydration, which means the grower’s paycheck also shrinks by 5%. Everybody likes a cut in pay, right?

The growers in the valley have been remarkably patient, probably hoping it’s a temporary situation, but as of a few years ago, they started holding meetings to discuss the situation and try to come to some kind of accommodation with local winemakers. Some winemakers prefer to purchase grapes by the acre so there’s no issue with yields and that practice may become more widespread if things continue as they are. It’s also been proposed that for every degree over 26%, the grower receive a 5% increase in compensation to balance his loss, but of course each grower and buyer must reach their own agreement.

Higher alcohols

The other effect of the higher sugar is higher alcohol in the wine. If the conversion rate during fermentation is between 50 and 60%, then grapes that come in at 28 degrees brix can produce as much as 16.8% alcohol! It’s a bit like having a glass of Port with your rib-eye steak. There aren’t many wines with a reading that high, but if you’re a label reader then you’ve noticed a gradual increase in the alcohol of California wines.

An article by George Vierra in Wine Business Monthly stated that in Napa Valley we’re picking grapes today that are averaging about 4 degrees brix higher than the average sugars at harvest in 1971 and that the average alcohols rose from 12.5 percent to 14.8 percent over 30 years. In the wines, the acid fell and the pH climbed. He also observed that the Robert Parker and Wine Spectator ratings climbed along with the alcohols. These days, even cold-climate imports are commonly higher in alcohol too. Big alcohols can give the wine more body and a sense of richness and lately many European brands have been mimicking California-style wines to score big with powerful wine writers.

In some cases the winemaker wants the extended hang time, but also wants to avoid the corresponding high alcohol. Finances come into play again: in America, wines above 14% alcohol have a tax that’s over 30% higher than those under, so for big producers this is a huge issue. There are also aesthetics to consider. The alcohol shouldn’t burn through in the aroma or flavor. We want the wine to be balanced.

Reducing the alcohol

The alcohol can be reduced a few different ways. The simplest way is to add water and the obvious concern that goes with it is dilution. Some producers view watering the wine as simply replacing what was lost on the vine due to dehydration. Others are more wary.

Legally, it’s a little murky. California law says we may only add as much water as is necessary to “facilitate the fermentation”. Many yeasts don’t perform well when the alcohol gets too high, so we’re permitted to water the juice or fermenting wine, if necessary, to get the job done. It’s a vague law and leaves a lot of room for interpretation.

There are also high-tech methods available. Nobody talks about this, but according to the two companies in California who supply this service over 1650 wineries out of a total of about 2400 statewide have sent their wine out to be de-alcoholized. That’s a stunning 68%, which is almost unbelievable because the practice is virtually invisible.

One method of reduction is called the spinning cone, which is widely used in the food industry. Basically, it’s a distillation column in which steam separates volatile compounds from liquids under a vacuum. A winemaker might send out 20% of his wine out for alcohol reduction and blend that back into the rest of the wine later, bringing the total alcohol down.

Reverse Osmosis is another option. In that case the wine is circulated, under a pressure of 1,000 pounds per square inch, against a flavor-proof membrane filter. A mixture of water and pure alcohol end up on one side of the filter and all the other wine constituents on the other. The water and alcohol mixture are distilled to separate out the alcohol and the remaining water is blended back into the wine. As with the spinning cone, this very low alcohol wine is usually blended with untreated wine back at the winery.

Even though these techniques are widely used, they’re still controversial. Purists will call it over-manipulation or a salvage effort. Others will say that if it gives the wine better balance the end justifies the means.

Sensory trials

Ed Webber wanted to include sensory evaluation in his study so he made wine from the same vineyards he used to analyze cluster weights. Two years in a row he harvested the grapes one week apart over a seven-week period, with average Brix levels starting at about 23 and peaking at as high as 29. His tasting panel very clearly noticed the progression from bright and tart in the wines harvested at low sugars to almost thick and syrupy for the wines harvested week 7.

He noted that metabolized sugar increases seemed to stop at about 26 degrees brix and that further sugar accumulation was due to dehydration. Another very interesting observation was that one vineyard that tended to make vegetal wine at low sugars still made greenish wine at 26 degrees brix. This calls into question the theory of picking late to avoid vegetal character.

So, you can see we have our work cut out for us. It’s encouraging because as good as the wines are now, they can only get better as we learn more each year. Regarding the differences between winery owners and growers, Mr. Webber summed it up very well. His view is that since we don’t have some other objective way to measure ripeness, the solution lies in building a good relationship with each other. It’s a good model for just about everything in life isn’t it?

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