The Rioja Harvest Festival has ended, but the harvest itself has just begun, three weeks later than usual. Whenever I see a Rioja winemaker, all but the oldest ones always say the same thing: “This harvest is the most complicated one I’ve ever experienced.” Recently, our local newspaper LA RIOJA featured an article by Fernando Martínez de Toda, chairman of the Department of Viticulture of the University of La Rioja that explains exactly why.
Rioja harvests have generally been uncomplicated since the early 1980s, a fact that Martínez de Toda attributes to global warming, with warm springs, long dry summers and the late onset of autumn rains. This has not been the case so far in 2013, characterized by a long winter, practically no spring and the late onset of summer. This year we were wearing coats until the middle of June.
Viticulture experts use the method of heat summation to measure the potential ripeness of grapes in a given region. Heat summation is calculated by taking the average temperature in degrees Fahrenheit every day the temperature exceeds 50ºF (10ºC) between April 1 and October 31 (in the northern hemisphere) because it is assumed that grapevines are inactive below that temperature. Each degree above 50º is one degree day. If Celsius is used for the calculation, the number of Fahrenheit degree days is divided by 1,8.
In Rioja, Martínez de Toda has calculated that until September 18, there were between 200 and 300 fewer Celsius degree days than in the same period in 2012. This means there’s a risk that the grapes won’t ripen in cooler areas – meaning most of Rioja Alta and Rioja Alavesa. The eastern half of Rioja, including all of the Baja will be spared. Most of these grapes have already been picked.
I’ve tried to explain to you many times that in ‘the old days’ (up to the 1980s) the large and medium-sized wineries in the western half of Rioja owned vineyards in Rioja Baja. This is the reason why. The grapes in the western half of Rioja simply didn’t ripen during many harvests and had to be fleshed out with ripe grapes from the Baja. It also explains why big wineries even today don’t usually own more than a few acres of vineyards. They would rather have farmers and cooperative wineries take the risk, with the wineries buying from the places that have turned out the best grapes and young wine that particular year.
For Martínez de Toda, this harvest also brings potentially good news. A downside of the long, warm growing season during the last 35 years has been an increase in the alcoholic strength of our wines along with a decrease in the formation of color in reds. This season’s cooler weather favors the production of elegant, more balanced wines with less alcohol and color that doesn’t have to be forcefully extracted.
Wineries and growers now have powerful analytical tools at their disposal to help them decide the best time to pick. Every vintage, the Rioja Regulatory Council takes weekly samples of grapes from 55 vineyards throughout the region representing different altitudes, the year the vineyard was planted and the grape variety. In each sample the following parameters are measured:
- weight of 100 berries
- probable alcoholic strength
- total acidity as tartaric acid
- malic acid
- total polyphenol index
- intensity of color
You can see the September 30 bulletin here.
This is a vast improvement over the decision to hurriedly pick on Columbus Day (October 12) with the help of a refractometer under the best circumstances or biting on a grape to see if it’s sweet, in the worst case. Some wineries still talk about this downhome approach to picking to show their attachment to tradition, but you can be sure that the decision is made in practically all cases by someone with a college degree in winemaking, biology or chemistry.
In Rioja, as in the rest of the world’s grapegrowing regions, the uncertain end result of each harvest reflects an aphorism from New York Yankees baseball star Yogi Berra: “It ain’t over till it’s over.” Here we also say, “One sunny day in October is worth 30 sunny days in September”.
In wineries throughout northern hemisphere, everyone, even the chemists, is keeping their fingers crossed.