What’s Up with the Rain and the Grapes? (2024)

FAQs

What’s Up with the Rain and the Grapes? ›

So, when it rains when the grapes are growing sometimes, it's too much water that will cause the grapes to be a little bit waterier or a lighter flavor compared to less rain then the grapes are more concentrated and thicker skins.

When grapevines get rain late in the growing season, some of that water is pumped into the berries. That reduces both the percentage of sugar and the percentage of acid in the grapes, at least temporarily. As long as you get dry, warm weather after, that dilution is usually short-lived.

More than that, if it rains, the grapes will take on more water, which means the flavors become dilute and the sugar/acid balance that winemakers are looking for gets out of whack. With too much rain, the grape berries start to swell and even split, and then you have to worry about spoilage, mold and mildew.

In conclusion, excessive rain, especially during the dormant season, can have a detrimental effect on soil health and grapevine growth. However, with the right precautions and management practices, vineyards can still produce high-quality grapes, even after extreme weather events.

Temperature. The overall optimum temperature grapevine growth is 77 and 90 degrees F (25 to 32°C). Any temperature below this optimum range causes vegetative growth to become limited. Temperatures above the optimum range reduce the grapevines photosynthesis rate due to the increase in respiration.

Too much sun can result in overripened grapes with high sugars and more intense tannins. Too little sunshine and the grapes won't ripen fully, plus you run the risk of drought and water stress on the vine.

Typically, in July and August, our grapes begin to undergo ripening, a process known as Veraison. During this stage, the fruit transforms from small, green, hard berries into what we recognize as grapes.

Grapes that are cooled naturally from nighttime temps also mean less energy use in the winery. But if you could harvest at night, when temperatures can drop as much as 40 degrees F from daytime highs, you're considerably ahead of the game, especially if the crop is big and the wineries are backed up. It buys time.

If there is a lot of rain during the planting season, farmers may have to delay planting, leading to delayed harvesting. Excessive rain can be damaging to soil, removing necessary nutrients that help plants grow. Too much water also leads to fungus and mold in the soil, which can kill crops.

Harvesting grapes between 1 a.m. and 6 a.m. helps guarantee the crispness of the berries, and the cooler temperatures of early morning help avoid a premature fermenting cycle.

Why do vineyards not burn? ›

“Forests have a lot of underbrush, so there's a lot of fuel for a fire underneath the canopies,” Kurtural said. Vineyards, by contrast, are well manicured. Aggressive pruning and leaf trimming regimens remove extraneous vegetation.

Wine grapes are harvested at around 22-30 percent sugar while table grapes might be closer to 10 or 15 percent sugar. This also means wine grapes deteriorate much faster when picked than grapes meant for the table.

The spotted lanternfly is known to destroy and feed on a variety of fruits, particularly stone-fruit like grapes, deeply threatening the multi-billion dollar California wine-making industry. A polka-dotted planthopper is threatening your evening glass of syrah.

Although available year round, peak season for grapes is the fall—September for green grapes and October for red. This is when they make their way to many a cheeseboard for tailgating and the start of the entertaining season.

The vines need full sun, because sunlight plays a major part in fruit sugar development. North-south rows maximize sun exposure. Northeast-southeast rows reduce sunburn problems in warm climates. Other important considerations: Grape vines have a large leaf surface and are susceptible to fungal diseases.

However, severe heat (> 105 °F) can reduce vine photosynthesis and slow sugar accumulation during ripening. In addition to yield losses, fruit quality may suffer from high heat spikes due to various effects. Extreme heat can slow sugar accumulation and increase malic acid respiration leading to reduced berry acidity.

Soil Conditions

Grapes hate to have their feet wet, so be sure proper drainage exists. If you plant them where there is too much water, even for part of the growing season, they will eventually succumb to root rot and die. They grow best in a deep soil with a pH between 5.5 to 7.0.

Grapevines are more tolerant of dry seasons than other fruit crops, and in some instances low levels of water deficit can increase fruit quality. However, excessive water stress can have a negative impact on yields, vine health and wine quality.

During the dormant season, grapevines are very hardy toward saturated and even waterlogged soil. Flooding a vineyard 40 cm (15.7 inches) deep with water for 40 days was an early (and effective) method of controlling phylloxera outbreaks.

When grapes are kept in water they gain water due to the process of endosmosis. Endosmosis is the process by which water moves into the cell when placed in a hypotonic medium. When cells are placed in a solution which is hypertonic to cell sap they lose water by the process of exosmosis and leads to the plasmolysis.