August 2018

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Harvest is here!

Though this season has been a challenge in the vineyard, the grapes are still ripening and it is time to start picking!  So far people have reported higher than normal pH, lower brix, and watery fruit. Not a surprise given the weather. But today the sun is out and the forecast (at least for a few days) looks pretty good. Lets hope this weather holds.

Following are a few reminders as you go through this season. 


Vineyard sampling

Harvest decisions depend on having reliable numbers coming out of the vineyard.  Regardless of the methodology you choose (cluster or berry sample, number of passes through the vineyard, etc…) it is important to choose your method and stick to it, which allows you to compare your samples from one occasion to the next. As you review your methodology, make sure you are taking a representative sample of the vineyard, the vine and the cluster.  Here are a few thoughts on each of these 


Sample preparation and testing

In order to get the most accurate measure of fruit chemistry, it is important to prepare your fruit samples properly and make sure your lab equipment is properly calibrated. Also, there are a few things to remember when measuring Brix, pH and TA on juice. 


Rot Protocols

“Like when you bring your umbrella, it won’t rain, or put snow tires on your truck it won’t snow, you give me the protocols and I won’t have any rot!” (Tim Jordan, Barren Ridge Vineyards)

It is in this spirit that I include a section on handling compromised fruit. It is good planning to have a protocol in place in case fruit gets infected with Botrytis or sour rot. Not all fruit is infected for the same reasons, and some of these interventions are more useful for one kind of infection than another, but there are some things to keep in mind in terms of winemaking with compromised fruit.  I have included a summary as well as references and links to additional resources, should you need them.


High pH

Most of the winemakers I have spoken with report fruit samples showing higher than normal pH values at lower brix levels. Some are picking at lower brix than usual to preserve acidity. This section gives a brief review of the concepts of acid and pH which may help inform winemaking decisions regarding acidity. 


Past WRE Studies

The purpose of the WRE is to provide practical answers to winemaking questions in Virginia. All of our previous experiments are posted on the website.  Most include methods as well as results. There are several studies from previous years on methods from skin contact to thiol maximization, reverse osmosis, saignee, cap management and many others. These are a good resource if you are still looking for new approaches to making your wine this year.

Experiments are listed by type, but can also be searched by keyword.

Here are a few that might be useful this time of year:

Managing Rose Thiol Character with Fermentation Temperature (2017), King Family Vineyards

Skin Contact vs Traditional Pressing of Petit Manseng (2016), Sunset Hills

The Effect of Juice Turbidity on Aroma Development of Sauvignon Blanc (2016), Stinson Vineyards

The Impact of Saignee on Wine Quality (2017), King Family