As the ripening period begins, veraison and sampling of the grapes begin. The challenge is getting a valid sample.

Pick 100 berries from 50 vines without looking. If you look you instinctively grab riper berries. A blind staff member would be best.

Most important? While gathering those berries eat some, chew them thoroughly, even the seeds. Ultimately flavor is most important and can’t really be measured by devices.

Crush and strain the berries.

Try to squeeze out as much juice as you can, every drop counts.

The juice needs to clarify so it can be accurately tested, particles will throw off the measurement; let it settle overnight in the fridge.

Or use a centrifuge. We have a 40+ year-old one bought at a going-out-of-business sale. It just needed cleaning and new wires.

See the sediment at the bottom of the test tubes?

Put a few drops of juice on your refractometer.

Write down the Brix number. When we get closer to ripeness we start measuring pH and titratable acidity, the other things easy to measure.