Big juicy clusters of grapes are hanging on vines practically screaming to be picked. While we’re anxious to get moving on the next wine vintage, we must be patient.

The grapes have to have just the right amount of sugar in them at harvest time to make sure your wine is perfect.

We have a neat little tool to help us measure the amount of sugar in grapes, it’s called a refractometer.

A refractometer is a small, handheld tool that uses a prism to measure the amount of sugar in a grape. The prism shows us how the liquid affects the bending of light. Different substances bend light in varying amounts.

Today, we’re checking our Noiret grapes. Noiret is a hybrid that produces a peppery dry red wine that’s similar to a Shiraz.

To start, all we have to do is pull back the cover and place a drop of juice on the lens.

We hold it up to the light to get a brix reading. The brix number is a ratio of sugar to water in the juice.

The scale goes from 0-32. We’re looking for 20-22 brix range.

If we reach 21 brix, your wine will be about 12% alcohol by volume. This reading shows us these grapes aren’t quite there yet.

We don’t rely solely on the refractometer. We also use our senses to find the best time for harvesting grapes.

We can tell a lot by tasting the grapes. If the skins are thinning out, we are getting closer to harvest. Another sign that we are getting closer is that the seeds are brown and hard. When the time is right, they should have a good crunch.

Now, when you enjoy your next glass of our local wine, you’ll be able to impress your friends with your new wine expertise!

If you liked hearing about the refractometer, you might also like to read some other behind-the-scenes posts about things like cluster removal, desuckering, or shoot positioning.

Please tell us what other topics you’d like to learn about in the comment section. Cheers!