What’s the Most Important Day of the Year for Wine? Harvest Day
How do we know when it’s time to pick our grapes? The most important day of the year is the day we pick because it determines the kind of wine we’ll make from those grapes.
We start with our senses of sight, touch, smell, and taste. We want our grapes to be rich in color, not green. A ripe grape will crush easily, but not be shriveled. A ripe grape is plump, thickly juicy and smells good. It’s a balance between sweet and tart. We also look for ripe seeds, which are brown.
It’s good to use our senses but it’s also important to measure. We measure sugar content, pH, and acidity level. Grapes are mostly water and sugar that will ferment to make wine. Brix is a term used to measure the sugar content of grapes. Brix is measured in the field with a refractometer.
When we think we are getting close to the desired Brix, we take a hundred berry sample and check it in the lab with a hydrometer. After checking sugar, we check the PH in the lab. You may remember pH from high school science class. It’s a measure of free hydrogen ions. As our grapes ripen and the sugar rises, the pH will usually rise, too.
Grape juice is full of natural acids, which lend important qualities to wine. Every time we measure Brix, we also measure acid levels. In a way, they’re opposites; as the Brix goes up, the acid levels go down. If they go too low, then the wine may be flabby.
Our results should fall within certain ranges for Brix, PH, and acidity. When our grapes get close to those ranges, we go pick a sample. We sample about 100 grapes from both sides of the vines, high and low, in sunny areas and shaded areas, and pick from different parts of each cluster. We squeeze our juice into a cup and take our measurements. If they are within our desired range, we pick on the next best available day! Finally, the grapes are ready, the day is cool and sunny, and hopefully, you are here. Let’s go pick!
