The Impact of Agrothermal Systems Heat Blast Treatments on Grape Ripening, Wine Chemistry, and Wine Quality in Virginia (2017)

The aim of this experiment was to determine measurable differences of grape quality by utilizing Heat Blast technology used to treat wine grapes. A block of Petit Manseng was divided into two separate sections. One section was treated with heat blast delivery to the canopy and fruiting zones using an Agrothermal Systems XT heat system. The other section was not treated with this technology. The treatment block was treated 1 to 4 times per month depending on stage of growth, with the treatment regime starting around veraison. The majority of treatments were near veraison. Chemical spray regimes were the same between treatments. All other vineyard and winemaking treatments between grapes were equal. Acidity and potassium was slightly lower in the heat-treated grapes. Quercetin and tannin slightly increased in grapes, whereas catechin slightly decreased. Wine chemistry was not very much affected except for lower malic acid levels in the heat treatment. The tannin content of wine with heat treatment was slightly higher for most compounds. Overall, these wines were not found to be significantly different. There was a very slight tendency for the Control to have higher Tropical Fruit intensity, Fruit Intensity, and Body. No major preference trends could be seen between wines. In the future, more studies should be performed with Agrothermal heat treatment and its impacts on fruit chemistry. These studies should look into multiple grape varieties, as well as closely monitor disease progression. The use of Agrothermal heat treatment in conjunction with different vineyard spray regimes should be investigated as well. Although more studies are needed to confirm this, these preliminary results suggest that heat treatment may be a beneficial tool for East Coast viticulture.

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