When do i harvest grapes

Grapes that get more sunshine typically have higher sugar levels than those that might be slightly shaded. The Numbers Yes, there are some numbers involved when evaluating grape ripeness so it means we have to head to the laboratory for some testing.

As the grapes ripen, sugar and pH increase as total acidity decreases. Finding the right sugar-acid balance is very important for making wine. For sparkling wines, we are looking for lower sugar levels and higher acid levels than grapes that will be used for still wines.

Sugar is measured using what is called the Brix scale, which is the percentage of sugars in the grapes. Brix levels are measured using two different tools. With the refractometer, the juice of the grapes is squeezed into the refractometer plate and the instrument is held toward the light. The sugar reading can be seen through an eyepiece. The other tool used to measure Brix is the hydrometer. This tool requires more grapes, but is more accurate.

We float the hydrometer in the grape juice and the sugar content is identified by the scale on the hydrometer. We use both methods as we get closer to harvest. We look at both the pH level and the titratable acid TA level when evaluating acidity ; both of these values change from vintage year. As the grapes ripen, the pH level will rise and the TA level will drop. Take a few grapes in your hand, and use your fingers and palm to lightly squeeze them.

Ripe grapes will feel plump and full of juice. On the other hand, immature grapes will feel hard and not have any give when you squeeze them with your fingers. Table or wine grapes that are left on the vine for too long will begin to shrivel and wrinkle, and have a dried-out texture.

Watch for birds on the grapevines. Birds will be able to tell as soon as the grapes have ripened, and will congregate on the vines in order to eat the grapes. If you see birds gathering around your grapes, you can be reasonably sure that the grapes are ripe. Taste a few to make sure.

Once you notice birds gathering on your grape vines, plan to harvest in the next 2 or 3 days. Part 2. Pick wine grapes in the early fall.

Wine grapes should be picked when ripe, but the grapes are usually ripe within a specific window of time. In the northern hemisphere, harvest wine grapes in August, September, or October. In the southern hemisphere, harvest wine grapes in February, March, or April. Grapes for wine should have a higher sugar content than table grapes. To achieve this, wine grapes are often left on the vine for 2—3 months after table grapes are harvested.

Since grapes that are used to produce jams or jellies are typically mixed with various other ingredients—including sugar—you can harvest them a little prematurely.

Harvest these grapes 3—4 days before you would harvest grapes that will be used for wine or eaten plain. If your grapes taste too sweet, you can reduce the sugar that you add to the jelly recipe. Leave grapes that will be used to make raisins on the vine for 3—4 extra days.

This will increase the sugar content of the grapes, which in turn will yield a tastier, sweeter raisin. The University of Minnesota is an equal opportunity educator and employer. Annie Klodd, Extension educator, fruit and vegetable production.

Related topics: Yard and Garden News Featured news. Share this page:. Page survey. The final stage in the grape harvest process is to sort the grape bunches, removing the rotten bits and other debris before the wine is sent to be pressed.

On to the next phase Home Journal19 Learn Liquipaedia When, why and how does the wine grape harvest happen? Liquipaedia When, why and how does the wine grape harvest happen? An anxious wait For several months of the year, winemakers all around the world face nerve-wracking growing seasons, where just the right amount of sun and rain are needed to grow grapes of the highest possible quality.

First steps Grape picking or grape harvesting is the first step of several in the winemaking process.