Timing of Harvest:
It’s been a long time since I have posted on this blog due to a busy semester, but as the season is approaching, I will begin posting again.
This past fall I taught a course on how to manage mature vineyards. In that course we focus a lot on pruning, canopy management, crop load management, and vineyard economics. In this particular section of the course it was comprised of roughly 1/3 of students only interested in grape production and 2/3 of students who were more interested in wine production, or were looking to get involved with both grape and wine production.
During harvest we collected some fruit samples at 3 different times of harvest, roughly 2 weeks apart. So, we had a range of about a month between the first and last samples. From these samples I froze a portion of the juice for tasting later, and small batches of wine were made from the rest of the samples in Ames.
Two of the cultivars that the students tasted were LaCrescent and Marquette. For this posting I’ll focus on the experience with the LaCrescent.
The students were given 5 different fruit samples: early, middle and last harvest; and sub sets of the middle harvest of shaded versus exposed clusters. The students were first asked to select the sample they liked the best. After the preference was identified they had try to determine which harvest they came from.
While there was some variability in the group, most found the middle harvest bulk sample or the middle harvest exposed sub sample to be the most preferred out of all of them. When asked to rank them in order of harvest, typically the sample they preferred was always assumed the last to be harvested, which was incorrect.
As we continued on with the discussion about why they chose the samples that they preferred, the discussion routinely went back to the fruit having a more ripe, fruity flavor and a more complex fruity flavor. The middle harvest samples were ranked as having the highest amount of that. After running the brix, pH and TA values the early harvest was around 19-20, ~3.1 and 1g/L; the middle was ~22, 3.2 and 0.95 g/L; the late was ~23, 3.3 and 0.9 g/L. The main parameters were different, but not as much as we might see in a very warm autumn.
Then I posed the question why most ranked the middle harvest to be the latest. Some commented that in their readings and discussions in other areas outside that course, the thought was that as fruit ripens the flavor gets more complex, fruitier, more desirable, etc. The conclusion that they were led to believe is that by harvesting later, they would typically get the best flavor. Students were then given wine samples made from the 3 different timing of harvests and again came up with the same basis preferences, sample order of harvest, and reasons for these preferences.
While this was by no means a scientific study, I think it points out the common misconceptions that we can not apply to every situation and shows the disconnection between those in grape production and those in wine production. What is clear is that flavor does change, but not always for the better. So by ridding ourselves of some assumptions, I think we can increase the potential quality of fruit grown with many of the new hybrids. While I am not a wine expert, I think paying close attention to what happens in the vineyard can help that potential.
Next time we’ll look at the experience they had with Marquette.