How to determine the harvest date of wine grapes?

The harvest time is the most essential part of winemaking because harvesting at the right moment is essential for the quality of the wine.

The harvest date is 100-110 days after full flowering depending on the variety and environmental conditions.

After the first pattern on the berry 45-50 days.

There are a few things to know on how to determine the right time for harvest.

Grape quality indicators

The epoch of variety maturation

Weather conditions

Wine typology that we want to produce (sparkling wine, light wine, dessert wine,…)

Grape quality indicators

The most essential quality indicators are Sugar level, acidity level, and the consistency of the berry.

These indicators are the ones that are of the most important in-home winemaking and are the easiest to determine.

But if you want to produce higher quality wine these are the indicators you need so you can try and make high-quality wine.

Sugar content in must

Acids content in must

The ratio of sugars and acids

pH value

Phenol content ( red wine)

Anthocyanin content (red wine)

Anthocyanin extractability (cell maturity)

The tannin content in the skin

The tannin content in the seeds

Synthesis of aromas and aroma precursors

Movement of nitrogen compounds

The portion of malic acid

Consistency of the berry

Berry mass (g)

The best way to determine the grape quality indicators is with a Refractometer

Here is a link to a Refractometer

Also, there are Digital refractometers

Tool for harvest time determination

It is easy to use you just need some light (sunlight) and you can measure the sugar level.

You need to pour a drop of grape juice into the glass and look through the lens to see the sugar level.

It is easy to carry with you so you can carry it to your vineyard.

Refraktometre sugar scale

The scale has a few different units of measurement but the main one that u need is Brix.

Why do you need Brix?

Because it is the unit of measurement for sugars.

You can take your Refraktometre to your vineyard to take a sample of your grapes to see if the level of sugar is optimal for winemaking and you can start the harvest in the next few days.

Here are some numbers for professional winemaking


220-260 for a regular harvest

Brix / acid content/10

30-32 for a regular harvest

37-38 for a late harvest