Stacey, Retail Sales & Wine Club Director
October 9, 2015 | Stacey, Retail Sales & Wine Club Director

Grape Expectations: Harvest Prep

Harvest 2015 has been in full swing, so it is about time I wrote about winemaking activities taking place during the harvest season! Most of our winery’s harvest takes place in September and October. Some late harvest wine grapes are harvested as late as November. This year, we started harvesting on Wednesday, September 9. I will describe what goes into preparation for harvest, and how we determine when to harvest.

First, a basic rundown of the growth cycle of our grapevines leading up to harvest: dormancy during the start of the year, bud break usually in April, flowering and berry set in May, the berries gradually enlarge in June and build up tartaric and malic acids (I will describe their fates in a later blog), then usually in late July we see veraison. This is when we start monitoring the grapes to determine harvest time and estimate how much we may harvest.


Veraison as seen in Cabernet Sauvignon grapes in our vineyard (left). Melanie taking fruit samples of Cabernet Sauvignon from our Riverside Vineyard (right).

Veraison is when ripening starts, and it is when the grapes start transitioning from bright green to their mature color, whether that is the golden-green of chardonnay or the blueberry-purple color of cabernet sauvignon. During veraison, the berries build sugars, which is when they become interesting in flavor to both humans and wildlife. That is why we put bird netting up on the vines just before veraison.

As grapes hang on the vines, they develop higher sugars and lower acidity. We then regularly measure the grapes’ sugar (measured in degrees Brix—°Bx—with 1 °Bx being 1 gram of sucrose in 100 grams of solution) and acidity, as well as evaluating the flavor of the grapes. Fruit samples are obtained on a weekly basis after veraison starts, and sometimes more frequently if needed. One of our winemakers or our winery assistant, Melanie Wetmore, zoom around the vineyard on our 4-wheeler to pick grapes from different varietals and various parts of the vineyard. They are put in sealed plastic bags in a cooler on the back of the 4-wheeler to protect them from the elements until sampling for the day is complete.

Grape samples in bags are then returned to the lab in our winery building. Yes, we have a small lab! The grapes are smashed in their bags to make pulpy juice. The seeds can then be seen to determine the percentage of brown seeds (indicating ripe berries) to green seeds (unripe). You want the percentage of brown seeds to be as close as possible to 100%. The juice is used to measure sugars and acidity, and it is poured into beakers for our winemakers, Jay and Jennifer Christianson, to taste. While tasting, Jay and Jennifer are assessing the flavors in the juice—specifically ripeness, tartness, fruitiness, and fullness—and they take detailed notes.


Pro Grape Smasher, Melanie Wetmore, preparing juice samples (left) and measuring total acidity (right).

Based on degrees Brix, acidity, and flavor, Jay and Jennifer decide when to harvest which grape varietals for different wines that they are making. The most important factor is always flavor, as long as the sugars and acidity are within an acceptable range. Some other factors are available tank space, availability of people to harvest, and weather. If many blocks of grapes are ready to harvest all at once, some of them just have to wait in line!

The next blog will describe grape harvest and crush!


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Stacey Smith
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