October is upon us and with that, the winding down of grape harvest. And for grape growers in the High Plains region, the grape harvest has been great! For the most part.
In spite of the hail damage in May, most vineyards were loaded down with grapes. While some of the hail damage stripped vines clean of fruit, others showed varying degrees of damage, and some of those vineyards still ended up with a surprising harvest this year, albeit smaller than hoped for. In many cases, these vines were hand harvested. And, while the quantity might not have been there for those with some hail damage, the quality has been excellent.
So, just how do you know when grapes are ready to harvest? The answer is, there is no one answer. It depends on the variety and what the winery wants. And the truth is, a whole lot of knowing comes from experience. There is definitely a science to it, but there is also the “look and feel” component.
Grape grower and science wizard Jet Wilmeth stated, “You start by looking and just kind of knowing that the clusters are beginning to look ripe. Then you pick a sample.” But you don’t just pick a cluster and use that for your sample. You take several clusters and pull a few grapes off each cluster and put them together to be tested by the wine lab. This gives you a better cross-section of what is actually on the vines.
“There is a lot of science to it, but there is a lot of it that just comes from experience and just knowing when it is time,” stated Jet.
The samples are tested for pH level and for brix levels. The pH is the acidity and the brix is the sugar. Again, it depends on the winery and the variety of grapes, but for whites, a brix level of 23-25 and a pH of 3.7-3.9 is in the general area of ready.
Some of this can be adjusted at the winery by adding acids or adding sugars, but the more additions that have to be done at the winery, the more the cost goes up.
Brix is a way to measure the potential alcohol content of a wine before it’s made by determining the sugar level in grapes. Each gram of sugar that’s fermented will turn into about a 1/2 gram of alcohol. Of course, different winemaking techniques will affect the final alcohol content.
The pH of a wine is critical not only to its flavor, but to nearly every aspect of the wine. It is second in importance only to the sugar levels. Variations in pH can definitely mean the difference between a wine not worth drinking and one that wins international awards.
The pH scale technically is a logarithmic scale that measures the concentration of free hydrogen ions floating around in your wine. The stronger the acid, the more hydrogen ions you’ll have, so in essence it is a measurement of how strong an acid is.
Acids have a pH less than 7.0 while bases have a pH higher than 7.0. Plain water measures 7.0. Most wines fall between 3.0 and 3.6.
Another way to tell how close grapes are getting to harvest is to look at the seed. A nice brown seed indicates a ripe grape. As stated, the whites are the ones that generally mature faster. They bud break earlier and that leads to an earlier harvest. Varieties such as Muscat Canelli, Viognier, and Gewürztraminer are those that are usually harvested first in the High Plains area.
The other factors that figure into harvest are the winery obviously, plus bin availability and trucks. The weather also figures into the mix. A rain slows down the harvest as the vines absorb the moisture and the sugar content goes down. Growers must wait a few days for the sugar numbers to come back up.
When grape harvest gets rolling, it moves quickly. Most of the harvesting is done in the night and early morning when the temperatures are a bit cooler.
Life in the country for this writer, yielded bright lights outside my windows in the early morning, as the Lahey Vineyards folks were working late and into the early morning hours with their harvest.
For the folks at Texas Custom Wine Works and newcomer, Texas Wine Company, work continued round the clock as bins loaded with the sweet fruit arrived. Both processors reported over 500 tons of grapes processed.
The recent wet spell on the High Plains has slowed those few trying to finish up, but for the most part, the harvest is done and it has been a fantastic harvest. Virtually every grower talked to feels that the 2017 harvest has been one for the books. But, life on the vineyard continues, as growers are already beginning to work on vines for the next harvest.