It’s important to measure grape sugar and titratable acid from veraison up to harvest. It allows you to predict when you will start picking, get everything in place and also to decide the optimal time to harvest for great quality grapes based on the Brix:TA Ratio (explained here).
Judging ripening and when to harvest is an art and science as often ripening isn’t a linear process. It’s important to have good data combined with your knowledge and experience to make the best decision for your vineyard.
Using graphs to show these trends makes it easier for you to know exactly what happens in your vineyard and make more informed decisions both this year and for many years to come. The graphs pictured here are taken from our app Sectormentor for Vines, they are automatically generated when you input the Titratable Acid (TA) and Grape Sugar readings into your phone.
The graph above shows how TA varies over time for each variety. Here you can see that for the Pinot Noir DF the TA level was falling quite linearly up until September 5th. At the same time the Grape Sugar level kept rising in a predictable way (see the graph below).
However after this date the acid and sugar levels were not changing linearly and in the end the extra 2 weeks the grapes had on the vines only changed the Brix:TA ratio from 2.2:1 to 2.3:1 and the TA hardly changed at all (head to the bottom of the page to see the numbers behind these ratios.). The optimal ratio for sparkling wines on this vineyard is 2.1:1 to 2:6:1, so as Will Davenport says:
“You can see that ripening is not linear. Sometimes weather affects ripening, but also you can see that some varieties ripen fast and then there is only limited benefit from leaving them on the vines for longer. The Pinot Noir DF figures show how useful the graphs are.”
By collecting this information in a clear and easy way you are able to better understand how each variety or block of vines ripens and when is the best time to harvest for each area of your vineyard. It is also easy to share this information between winemaker and vineyard manager, so you can make a joint decision for each area of the vineyard or variety about when to harvest.
If you are interested in using Sectormentor for Vines in your vineyard then contact us here
Aug 28 Brix:TA = 1.6:1
17.7 Brix (73 Oeschle) | TA = 11.1
Sept 5 Brix:TA = 2.2:1
19.5 Brix (80 Oeschle) | TA = 9
Sept 18 Brix:TA = 2.3:1
20.7 Brix (86 Oeschle) | TA = 8.9