The harvest of grapes and other agricultural products is shaped by the daily variations in temperature between day and night, soil and water.
For grapes, sunny days and cool nights are ideal. Sunny days develop fruit sugars for fermentation, and cool nights are essential for this balancing acidity. Water, whether it is a little rain or irrigation, is the other important factor.
The challenges of climate change are extreme temperatures and lack of water for everyone. Cooking temperatures during the day, hot temperatures at night, and water scarcity can lead to poor crops.
Across the world this year, damage to vineyards from drought, forest fires, floods, frost and hail will be felt over the next few years. The devastating effects of climate change are becoming more and more frequent.
The most damaging events of this year have occurred in France, Italy and California. The French regions of Burgundy, Languedoc and Bordeaux were hit by spring frosts just as the vineyards were budding. About 80% of the vineyards were affected by the sudden drop in temperatures. The silver lining – the roots are still healthy, it’s just the crop that was lost.
And recently, a forest fire swept through part of Provence in the south of France a few days before the harvest. Buildings, equipment and vineyards were lost. Provence is best known for its rosé.
This year, the harvest in Italy started seven days earlier than in 2020 – in the south. The ripening of the grapes was accelerated by prolonged temperatures above 104.
In the north, the estimate is around 10 days behind normal picking times due to frost in Prosecco during the first 10 days of April and summer hail on vineyards in Veneto and Trentino .
In Germany, according to the National Weather Service, two months of rain fell in just 24 hours. In the lush Ahr valley, a tributary of the Rhine, a century flood has seriously damaged this wine region.
In California, drought conditions in recent years have taught vineyard managers the benefits of leaf canopies and row spacing. Leaf canopies shade the grapes preventing sunburn. The size of the crop during a drought resulted in decreased growth of smaller clusters and berries. This is because the vines stop when it gets too hot.
Many expect this year’s yields to be around 20% below the average yield. A short crop in 2021 would be the second reduced crop for California in as many years. According to industry reports, 3.4 million tonnes of fruit were crushed in 2020, 20% less than the average. Less development and smaller berries due to drought led to a smaller crop size.
The Californian harvest began the first week of August, a week earlier than last year. Sparkling grapes are always the first grapes to be harvested because the grapes are picked at lower sugar levels than still wines.
A similar story is unfolding in Washington, with smaller harvests in 2020 and 2021. The Washington State Wine Commission reported 178,500 tonnes of wine grapes harvested in 2020, an 11% drop from 2019. The larger harvest low of 2020 was due to three main factors. events: a frost in October 2019, some areas had wind and rain at the time of flowering, then there were several days of smoke due to forest fires which impacted the timing of the flowering. picking, if at all.
2021 is expected to be smaller than 2020. This was a direct result of the more than 110 weather conditions in June. Growers have seen sunburn and sometimes the grapes shrivel up on the vine. Vineyards that have covered vines during extreme temperatures have little heat damage. Estimates show cluster sizes down 30-40% from last year in many blocks.
Most blocks of white grapes this year will be 4 to 5 tons per acre compared to the normal 7 tons. With red grapes, it is 2½ to 4 tonnes whereas usually it is more in the order of 3 to 5 tonnes per acre.
The Washington sparkling wine harvest began in the Yakima Valley in mid-August. According to Juergen Grieb, owner of Treveri Cellars, “The fruit looks good, but the berries are smaller and the weight of the vineyard is smaller. “
The 2021 harvest at Bacchus vineyards in Sagemoor started last week. More than 20 grape varieties will be harvested at any time of the day, sometimes by hand, sometimes by machine. And over the next few weeks, Sagemoor teams will harvest around 4,400 tonnes of grapes for more than 120 wineries.
In Oregon, the story is the same. Pinot Noir and Chardonnay are fresh grape varieties, unlike Syrah and Grenache which love heat. The smaller crop sizes in the 2020 crop have been made even smaller due to the smell of smoke. Smoke blanketed the vines for the first two weeks of September 2020.
Smoke from the wildfires will also contribute to a smaller crop for 2021. Demand for Oregon wine will likely exceed supply in the next few years.
Wine schools and vineyard managers are considering ways to combat these extremes by changing vineyard design, vine spacing, canopy management, and even changing varieties to more heat tolerant varieties. These conversions have been going on for several years now.
So do your part: conserve the water, drink the wine! Cheers!
Mary Earl has been educating Kitsap wine lovers for over 20 years, a longtime member of the West Sound Brew Club, and can accompany a beer or wine dinner in a flash. She volunteers with the Clear Creek Trail, is a member of the Central Kitsap Community Council and a long-time supporter of Silverdale.