When to Harvest?

[SenseAG]

Is this the most crucial question with no precise answer yet?
When is your time? Color? sugar? acidity?
We don't want to miss the right moment this year, any advices will help

 

[KevinL]

Depends on where you are and the variety of grapes that you're harvesting. pH is a big factor for most people, as if it gets too high, then your wine will be more susceptible to spoilage.

I've got a lot of Northern Hybrids, and I track TA as a harvest parameter. It also depends on what kind of wine you expect at the end. So yes, there really is no precise answer. I suppose one of the easiest answers is "When the grapes are ripe, and you have time to do it." A perfect combo of TA, pH and Sugar doesn't mean anything if you're not free to do the job.

 

[salcoco]

once the color change has started start monitoring sugar every other day and record same. about every fourth day measure acidity and ph. continue in this manner until sugar level normally 22-24 brix is achieved. once getting to 20 brix start monitoring every day. also make acid and ph measurement every day at this point.
what you should normally see is the sugar level rise and the acid level drop. the ph will go up as the acid rate goes down. once sugar , acid and ph are correct pick the grapes. okay this is ideal condition, if storms are on the horizon that may damage grapes then picking earlier may be necessary. then the must require adjustment.

 

[sour_grapes]

Caveat: I am not a grape grower. I learned on this forum that some grape growers go by (believe it or not) Brix * pH^2, that is, Brix times the square of pH. It may help you to google that phrase if you are interested. Example:

"Keep measuring. Don't let the pH go above 3.3 with
whites or 3.5 with reds. Harvest when the Brix:TA ratio is as close as
posible to 30:1-35:1, and when Brix times pH squared is as close as
possible to 200 for whites and 260 for reds."

 

[BigH]

Is this the most crucial question with no precise answer yet?
When is your time? Color? sugar? acidity?
We don't want to miss the right moment this year, any advices will help

It is heavily variety dependent for me. I harvest Edelweiss and Brianna almost exclusively by brix, with a spot check on pH hoping it is within ear shot of 3.0. I harvest St Croix mostly by pH and the state of the skins, with a check on sugar between 18 and 20 brix. Marquette and Frontenac are governed mostly by TA, but I don't bother measuring it until sugar and pH indicate that it may be time. Frontenac Blanc and La Crescent are a combination of sugar, pH, and how the sun is impacting the berries. I pick La Crosse based on sugar and pH, with an eye towards thunderstorms that might split the berries. Petite Pearl is governed by when the Frontenac was harvested. Don't get too excited about measuring his sugar and pH until I get the Frontenac off the vine.

With all varieties, weather plays an important factor. Last year, a question to this forum played a big role in when I harvested petite pearl.

H