Tasting Grapes for Maturity

Grapes Changing Color

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Nicholas Solga photographs grapes changing color from green to purple, a critical time known as veraison.The changing colors in this bunch of grapes denotes that the plant is shifting its energy production to favor fruit. CC-attribution: Photo by kvins.com Once the grapes turn purple, the plant will grow less foliage and less vines.  The fruit will become riper and more concentrated. CC-attribution: Photo by kvins.com
Nicholas Solga photographs grapes changing color from green to purple, a critical time known as veraison.
Nicholas Solga photographs grapes changing color from green to purple, a critical time known as veraison.
The changing colors in this bunch of grapes denotes that the plant is shifting its energy production to favor fruit. CC-attribution: Photo by kvins.com
The changing colors in this bunch of grapes denotes that the plant is shifting its energy production to favor fruit. CC-attribution: Photo by kvins.com
Once the grapes turn purple, the plant will grow less foliage and less vines.  The fruit will become riper and more concentrated. CC-attribution: Photo by kvins.com
Once the grapes turn purple, the plant will grow less foliage and less vines. The fruit will become riper and more concentrated. CC-attribution: Photo by kvins.com

Grape Maturity

Like virtually all healthy plants, grapevines convert sunlight into energy. At a certain time of year, the plant starts storing the energy in its fruit to make delicious grapes. Early in the summer the grapes are very bitter and literally green. By the fall, the grapes are and start to taste sweet.

Since fermentation turns sugar into alcohol, winemakers can predict how alcoholic wine will be by looking at the sugar level of the grapes. There are a lot of very advanced methods to determine the sugar level and potential alcohol, but one of the best tests is a good old-fashioned taste test.

How to Taste Grapes for Maturity

Why Taste?

In this day and age, there are lots of ways to figure out the sugar content of a grape and you can easily estimate the sugar content of a whole parcel of vines. Tools like refractometers measure the amount of sugar in your grape's juice just by measuring how much the juice refracts light. This refraction reveals density, sugar level and potential alcohol.

So why rely on taste buds which aren't as scientifically accurate or precise?

  • Tasting grapes is fun and yummy
  • Testing more than sugar content

First of all, it's fun and easy to go out and plop a yummy grape in your mouth. Of course, if the grapes aren't very mature they'll taste very bitter and wine grapes are often less appetizing than the table grapes you buy in the store. But a really mature grape will have a lot of attributes other than sweetness.

You can taste distinct types of acids and sugars that come from the skin, pips and flesh of the grape separately. Sometimes, you can even get the undertones and flavor profile that the grape will eventually contribute to the finished wine. After all, the qualities of a wine start on the vine.

Pure sugar tests are no longer the norm for most winemakers who know that you gotta have a lot of things other than sugar to make good wine. If you've got healthy, mature grapes then they will benefit from extended contact with the skin and seeds during fermentation.

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Comments 6 comments

robie2 profile image

robie2 7 years ago from Central New Jersey

Hello Mr. O'Connell-- how nice to see your smiling face and wine expertise back here again on Hubpages. Where ya been???


Sufidreamer profile image

Sufidreamer 7 years ago from Sparti, Greece

Nice Hub - tasting is certainly the best way. I do not know a single person using a refractometer here, yet they still make fine wines.

Look forward to reading more of your Hubs - we have a lot of grapevines, so your expertise will be useful to us!


mroconnell profile image

mroconnell 7 years ago from France Author

Robie2 - Good to be back! I've been busy making the wine. But I'm back for a bit to do a big wine capstone.

Sufi - I hope it helps. Take everything I say with a grain of salt and keep enjoying the 16+ hubs I'll be releasing on winemaking. :)


Frieda Babbley profile image

Frieda Babbley 7 years ago from Saint Louis, MO

wow! What a great video, love it. Exciting job in an exciting place it seems. Way cool hub. Thanks for sharing the info.


Nomascus concolor profile image

Nomascus concolor 4 years ago from A Country called Earth

Great hub! Video makes me want to get some grapes too! It reminds me when I was harvesting in the languedoc ;) hope you enjoy it there


Susie 20 months ago

What a neat aritlce. I had no inkling.

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