I’m often asked by people visiting my vineyard to suggest a grape variety that is good for both eating and for wine. Are there such grapes? The answer is yes and no.
Most wine grapes have higher sugar and more acid than most table grapes, which makes them very tasty indeed. IF you don't mind seeds, soft pulp, and relatively tough skin when you’re eating your grapes then wine grapes aren’t that bad.
Table grapes frequently have less sugar, but lower acid too, so they taste sweet. They often have flavors that may or may not work in wine. Generally, they do not have the ratio of sugar and acid that is needed for a good wine.
Any grapes can produce a wine, but it's not necessarily going to be something wonderful. It depends a lot on how you handle the grape in the winemaking process and what sort of wine you make. If you make a dry wine out of Concord, and most likely you'll have something just fine for a multi-purpose cleaner, but not for drinking. American grape varieties usually only work if there is some residual sweetness in the wine to keep it from being harsh.
Then there are grapes that go the other way. Make wine from the Thompson Seedless white grape and will have something that is no more than water and alcohol. It will have little flavor and character. The wine flavors and attributes you’re looking for will be missing.
To make a long story short, you can make wine from any table grape variety, but you'd better be an experienced winemaker and know how to balance the strengths and weaknesses of the varieties you grow. You won’t end up with the best of wines, but once you’ve learned the attributes of the variety and how to manipulate them in the wine making process, you might come up with a good "vin ordinaire".
If you want just one grape to do everything, you'd better be an experienced winemaker with the ability to coax vinous properties out of a table grape, or get used to eating your smaller, seedier wine grapes.
Having said all that, here are a few grapes that are sort of borderline and can go either way, with work.
I’ve personally made wine from both Swenson Red and Edelweiss. I generally think of these varieties as table grapes. In fact, Swenson Red, although seeded, is my favorite table grape of all that I grow. But it does make a very nicely balanced white or rose wine.
Winemakers in Minnesota and elsewhere have made pleasant slightly sweet wines from Edelweiss. It has a slight hint of "foxiness" if the grapes are very ripe. It is best to harvest this variety a bit early at around 15-16 Brix to prevent this off flavor from occurring in your wines. You'll need to add sugar to bring the Brix to winemaking standards and get the desired result you’re looking for.
There are other varieties that can be multi-purpose and serve as both eating and table grapes. I have no experience with these so will not comment upon them. The best way to find out if your table grapes are worthy of wine is to make some. I would start with a sweet wine or a drier version with some residual sugar. Generally speaking dry wines made from table grapes tend to be disasters.
Experimentation is the name of the game. You can only try making wine from what you have to find out if your varieties are good enough. In the long run, I would suggest that you grow varieties that suit the purpose: wine grapes for wine and table grapes for eating.
