Many people have written to me inquiring about making wine from grape concentrates. By this they mean cans or bottles of concentrate sold specifically for making wine. My honesty is not always appreciated by those who are determined to make wine from concentrates, but in general I am not a fan of wines thus made. I will attempt herein to explain why.
Most grape concentrates are made by boiling grape juice at reduced pressure to eliminate about 75-80% of the water naturally present. In principle, making wine from concentrates is a simple, straightforward matter. A can or bottle of concentrate is opened and mixed with the amount of water specified in the instructions--usually the amount that was removed to make the concentrate. A packet of additives may be included for mixing with the restored concentrate--pigments, tannins and trace elements that were left behind with the skins when the grapes were originally pressed. Finally, a packet of wine yeast is sprinkled into the reconstituted juice and the fermentation process begins.
Many concentrates suffer from a variety of deficiencies. The grapes used to make the concentrates are not always quality grapes. The best grapes will naturally be selected by commercial winery representatives and jobbers, who are often present during harvest and select the soundest, ripest and sweetest grapes. What is left is then available for making juice, concentrates and occasionally raisins.
Several qualities for which particular grapes might be valued in winemaking, especially fragrance, color and varietal character, are largely lost during the concentration process. If higher temperatures are used to speed up concentrate production, some of the natural sugar may caramelize into 2-hydroxymethyl-furfural and other unstable compounds. The resulting off-odors and flavors negate the possibility of making a really good wine from the concentrate, and if the winemaker errs anywhere in the winemaking process a truly poor wine can result.
Other shortcomings of grape concentrates include paler, shorter-lived red wines than red grapes would yield, the tendency of older concentrates to produce hazes that are difficult to remove, and darker white wines from concentrates stored improperly or too long.
These are general criticisms and are not deserved by all concentrates. But even if they do apply to a concentrate, it may still be desirable to make wine from it.
Despite their many shortcomings, concentrates can play an important part in your winemaking experience. This is especially true in areas where grapes simply don't grow, as in extremely frigid or arid climates, or where fresh wine grapes or frozen musts or juice are not available at an affordable price, or in areas where particular grapes of interest are not grown. Concentrates then become your only practical avenue toward making affordable grape wines.
With concentrates, you don't need to contend with hauling, crushing and pressing bulk grapes and all the various processes required to make different types and styles of wine. You simply buy the appropriate concentrate and follow the directions. For most people, these factors override most of the cons. Secondly, because they are available all year 'round, making wine from concentrate can be done at any time--not just when grapes are harvested. Finally, you can make wines whose grapes you might never encounter in your area, another important consideration.
But even if a concentrate produces a bland, low-acid wine, such wines are perfect for blending with highly-acidic and often assertive-tasting wines made from native American and Canadian grapes. The foxy, musky or somewhat astringent qualities often found in native grape wines are greatly improved by mixing with wines made from grape concentrates.
Weak-bodied non-grape wines can be improved in the same way (by blending) or by adding a small amount of concentrate directly to a must known to produce a weak-bodied wine (watermelon and most flower or herbal wines are perfect examples). For these purposes, however, I strongly recommend you use an inexpensive general purpose frozen grape concentrate. Two such concentrates I've found useful for adding to non-grape musts are Welch's 100% Grape Frozen Concentrate, made from 100% Concord grapes, and Welch's 100% White Grape Frozen Concentrate, made from 100% Niagara grapes. These make far more sense than opening a $25 to $40 half-gallon can of Merlot or Sauvignon Blanc concentrate.
With concentrates, like many products, you usually get what you pay for. Pedestrian priced products usually produce pedestrian wines, but there can be exceptions. But generally speaking, the higher quality products are also the higher priced ones. These concentrates are usually made with the same quality grapes as the wineries and jobbers compete for. They can, indeed, make very good wines.
If you are going to make wines from concentrates, try to ask someone who has done the same for recommendations. Your local homebrew/winemaking shop operator should be able to make sound recommendations based on his or her customers experiences. If you don't happen to have a local homebrew/winemaking shop, call one of the online shops with a toll-free phone number.
If you have very good or very bad experience(s) with a specific concentrate, I'd love to hear about it. Please email me at firstname.lastname@example.org but do not ask me to recommend a concentrate. I will not do it. Jack Keller