The Mustang Grape (specifically, the Vitis Mustangensis), identified variously as a variety of Vitis Rotundifolia (Buckley, in error) and Vitis Candicans (Englemann, the accepted name for decades), grows wild all over south, central, and east Texas, and in fact is found in northern Mexico, Oklahoma, Arkansas, Louisiana, Mississippi, and Alabama as well. The vines climb trees, cover brush, and run along fences, putting out runners (canes) up to 300 feet in length.
We have several Mustang Grape vines on our property, with the base of the vine reaching a respectable eight inches in diameter. Like all grapes, berries appear on buds from last year's wood. The clusters are very small, numbering from 2 to 20 berries per, that ripen to jet black with varying bloom, redish-purple, and even bronze. The high acidity in Mustang Grapes can cause severe skin irritation until the acidity is corrected. For that reason, wear rubber gloves when picking, handling and squeezing these wild grapes. The gloves will also keep your hands from staining purple.
In my area of south central Texas, the Mustang Grapes ripen and begin to fall from the vines by late June. We harvested our first lot 20-21 June and our last on 5 July and started 15 gallons of wine in three batches. The harvest here runs through late July (with some ripe berries hanging on into the fall), but in northern Texas and the Texas Hill Country harvest will be in full swing by the end of July.
Mustangs are very acidic, tart and almost impossible to eat with any degree of enjoyment. Indeed, their acid is so strong it can burn the mouth. It therefore surprises many that Mustang Grapes make such outstanding wines. The acid must be corrected, of course, but this is usually done by dilution with water and/or cold stabilization and chemical intervention. Their natural sugar is insufficient to make a self-preserving wine and must be supplemented, but many native grapes suffer a low Brix. Notwithstanding the displeasure some winemakers have regarding water dilution and sugar addition, the resulting Mustang wine is often outstanding. This does not surprise Texans, but outsiders who taste the grape are usually astounded by the wine.
The natural tendendcy with Mustang Grapes and other acidic natives is to over-sweeten the must. This can result in retarding or even preventing activation of the yeast, and if that doesn't happen the result will, of course, be a lengthy fermentation and a very sweet wine. A lengthy fermentation can produce off flavors which cannot be corrected except by blending, and even then only partially so. Another danger is that fermentation will slow to the point where one assumes it has stopped when it really hasn't. Bottling such a wine without stabilizing it can be either dangerous or serendipitous -- dangerous if the corks pop (or, worse, the bottles explode) and serendipitous if a sparkling red results in intact bottles.
The Mustang, like many North American native grapes with a wet stem scar, has slip-skin fruit. This means that the skin will rather easily slip off the pulp of the fruit if pulled or squeezed just right. In turn, this means it can, with a little additional work, be prepared for fermentation without its skins, thereby producing a clear white wine. Pressing immediately after crush will result ina pale blush wine. But, since much of the "Mustang" flavor is in the skins, the flavor of the white and blush Mustang will be very different from the red Mustang. This flavor can, to some degree, be retained by fermenting the white/bronze varieties of the grape on their skins. Also known as the "Bird-Free Mustang" (Parsons), the white is rare in the wild (usually appearing as a bronze) but can be found.
The recipes below are arranged from dry to sweet. They ask for a lot of grape and make very "full-flavored" wines with a wild tang to them. In fact, half the amount of grape could be used for smoother, less "wild-tasting" wine. To use less grape, adjust the sugar for a starting specific gravity of 1.110. For the sweeter ones, begin with half the sugar dissolved in the must and the remainder dissolved in water and reserved. Add half the reserve to the must when the S.G. drops to 1.035, then add the remainder about three days later. This will lengthen the fermentation time, but not unnecessarily so. More importantly, it will not retard or stop the fermentation process.
Remove the stems and wash the grapes. While wearing rubber gloves, crush the grapes in a crock or polyethyline pail. Add all ingredients except yeast. Stir well and cover for 24 hours, then add yeast. The must will form a floating "cap" of skins and seeds which should be pushed under and stirred twice daily for 5 to 7 days. Strain and press pulp well to extract liquid. Measure acidity, then follow one of the methods below to reduce the acidity to 7 parts per thousand (p.p.t.) tartaric if necessary. Pour into secondary fermentation vessel, fit airlock, and let stand three weeks. Rack and top up, then rack again in three months and add fining. Bottle ten days after fining. May taste immediately, but improves remarkably with age (3-4 years). [Adapted from a traditional "wild grape" recipe.]
Remove the skins while the grapes are still on the stems, then remove the skinless grapes from the stems. Wash the fruit and put in nylon jelly-bag. Tie end of bag and, while wearing rubber gloves, crush the grapes in the bag over a crock or polyethyline pail. Add all ingredients except yeast. Stir well and cover for 24 hours, then add yeast. Push the bag under liquor twice daily for 5 to 7 days. When vigorous fermentation subsides, squeeze pulp well to extract liquid. Measure acidity, then follow one of the methods below to reduce the acidity to 7 parts per thousand (p.p.t.) tartaric if necessary. Pour into secondary fermentation vessel, top up with water, fit airlock, and let stand three weeks. Rack and top up, then rack again in three months. Bottle when clear, or add fining after two weeks if wine doesn't clear. Bottle ten days after fining. May taste immediately but improves remarkably with age to about three years. [Author's recipe.]
Remove the stems and wash the grapes while boiling water. While wearing rubber gloves, crush the grapes in a crock or polyethyline pail. Add all ingredients except Campden tablet, pectic enzyme and yeast. Add boiling water and stir well to dissolve sugar. Cover. After two hours add crushed Campden tablet and after additional 10 hours add pectic enzyme. Twelve hours later add yeast. The must will form a floating "cap" of skins and seeds which should be pushed under and stirred twice daily for 7 days. Strain and press pulp well to extract liquid. Measure acidity, then follow one of the methods below to reduce the acidity to 7 parts per thousand (p.p.t.) tartaric if necessary. Pour into secondary fermentation vessel, fit airlock, and let stand 30 days. Rack and top up, then rack again in three months. Bottle when clear, fining if necessary. May taste immediately but improves remarkedly with age. [Author's recipe.]
This wine may have too strong a "wild" flavor for some. It can be blended with almost any thin wine without detracting from the flavor. Remove the stems and wash the grapes. Place in large pot with one cup of water and set over low to medium heat, covered. Stir with wooden paddle every 10 minutes until grapes break apart and juice oozes out. Allow to cool. Meanwhile, boil water and pour into crock over sugar, stirring to dissolve. Set half of sugar-water aside in quart jar. When grapes are tepid, over crock pour grape juice and pulp into nylon jelly bag, tie bag and leave it crock with juice. Add yeast nutrient and pectic enzyme. Cover and set aside 10-12 hours. Add yeast and re-cover crock. Use wooden paddle to push bag under juice twice daily for 7 days. Drain bag and press pulp well to extract residual juice. Measure acidity of liquor, then follow one of the methods below to reduce the acidity to 7 parts per thousand (p.p.t.) tartaric if necessary. Pour into secondary fermentation vessel, top up with reserved sugar-water, fit airlock, and let stand three weeks. Rack and top up with remaining sugar-water, then rack again in three additional weeks. Set aside two more months. Rack and allow to clear. Wait one month. If lees are still being deposited, allow another month. Stabilize at 1.000 to 1.008, allow 10 days for all yeast to precipitate out, rack, and bottle when clarity returns. May taste immediately but improves remarkedly with age. [Author's recipe.]
Destem and wash the grapes. While wearing rubber gloves, crush the grapes in a barrel, crock or polyethyline primary. Add water, 2 lbs sugar to start, nutrient, and crushed Campden tablets, stirring well to dissolve sugar. Cover and let stand 24 hours. Add yeast. Stir every morning for 5 to 6 days, or until all solids rise to top to form a floating "cap" of skins and seeds. Remove all solids and strain juice through a cloth sack. Add remaining sugar (10 lbs if using Montrachet yeast, 13 lbs if using Lalvin 71B) and stir well to dissolve. Pour (better yet, siphon) juice into glass secondary (do not top up) and fit airlock. When fermentation stops, rack, top up, and refit airlock. Rack again in two months and again two months later. Bottle without sweetening. The Lalvin 71B yeast will yield a higher alcohol content. May taste right away but will "mature" in 1-2 years. [Adapted from Poteet Country Winery recipe by Alvin Sueltenfuss, Boerne, Texas]
The early German and Czech settlers in Texas developed a very good system for making wine from the native mustang grape. This grape grows along fences over most of Texas, and the fruit will be ripening in July and early August. The following is a typical Czech recipe used in Texas for Mustang Wine. It was handed down for 3 generations to Bob Rozacky of Granger, Texas.
Harvest. Start with fully ripe, rain-washed mustang grapes on the cluster. Do not de-stem. Start the fermentation as soon as possible. Do not let the fruit sit for several hours. When the pickers come in from the field, have your equipment read to go. Remove any green leaves or any foreign matter. Fill a very clean, 10-gallon crock or plastic garbage can with fruit. Do not use metal, galvanized, or aluminum cans. Crush the fruit down to a soggy must. Acid of the fruit can blister your skin, so Rozacky uses a clean, non-treated wooden board, 4 inches by 4 inches by 6 feet long (4"X4"X6’).
Primary Fermentation. Naturally-occurring yeasts on the skin of the grapes will begin to multiply, utilizing the sugar in the grapes, so no yeast need be added; however, some wine makers use bread yeast or wine yeast purchased from a wine shop. This primary fermentation will begin in 2 or 3 days in the 10-gallon container. Do not add water, do not add sugar, and do not add starter yeast. Let the natural primary fermentation take place. This can be done in a garage, on the back porch, or in a crib or barn . . . any warm place. It is very important to tightly cover the top with a clean cloth to keep insects out. Check the grapes daily. Do not stir the must or crushed grapes. The speed will begin to pick up in 2 or 3 days, and you will be able to see and hear the bubbles of carbon dioxide gas. This is a good sign that fermentation is progressing properly. Allow the primary fermentation to run its full course. You can tell when it stops, because the must cap on top of the raw wine will drop, and you will hear no more bubbles. The deep red color and tannin are extracted from the grapes during primary fermentation.
Secondary Fermentation. The next fermentation should take place in a clean 5-gallon glass carboy. Siphon off 2-1/2 gallons of the raw wine into the 5-gallon carboy. Press the rest of grapes in a nylon straining bag by hanging it up and letting the raw wine drip through the nylon mesh. Add 2-1/2 gallons of previously boiled sugar-water to 2-1/2 gallons of raw wine [to make sugar-water, boil 2-1/2 gallons of water, add 10 pounds of sugar, and cook until the mixture comes to a full boil; cut off the heat, and allow the sugar-water to cool all the way down to room temperature]. Completely fill a 5-gallon glass carboy with enough of the raw wine and sugar-water mixture so that no air is present in the bottle. The secondary fermentation will begin in 2 or 3 days; cork the carboy with an air lock. As the wine continues to ferment, carbon dioxide will be released, and the wine level will go down. Add sugar-water daily to keep the carboy full. After you see no more bubbles -- in about 2 or 3 weeks -- you are ready to seal the carboy. Be sure it no longer bubbles. The alcohol in the wine will kill the yeasts, and stop further fermentation. The sweetness of the final wine will be determined by how much sugar is left in the wine when the yeasts are killed by the alcohol. Let the wine age in the glass carboy for 6 months until cold weather. In December, after a freeze or frost, siphon wine into bottles, and cap or cork. Label bottles with date and year.
If the acidity of the grapes is too high, further acid reduction may be required. Here are three methods....
Acid Reduction with Calcium Carbonate: For liquors with acid levels of 10 p.p.t. or more, calcium carbonate is traditionally used to reduce acid through precipitation. A measured 2.5 grams of calcium carbonate will reduce the acidity of one gallon of wine or liquor by one p.p.t. For best results, split the liquor into two equal portions and add the calcium carbonate to one while stirring vigorously. Carbon dioxide will be given off and cause foaming. Chill the treated liquor several days and then siphon it off the lees of calcium carbonate into the untreated portion. The addition of a teaspoon of yeast energizer may be required to reactivate fermentation after treatment.
Acid Reduction with Potassium Bicarbonate: For liquors with acid levels of 8 to 10 p.p.t., potassium bicarbonate treatment can be used to reduce acid through precipitation and neutralization. A measured 3.4 grams or 0.1 oz. of potassium bicarbonate will reduce the acidity of one gallon of wine or liquor by one p.p.t. The compound is stirred directly into the full batch, then chilled to facilitate precipitation of potassium bicarbonate lees. The addition of a teaspoon of yeast energizer may be required to reactivate fermentation after treatment.
Acid Reduction through Water Dilution: This is the least desirable method, only because the Mustang Grape flavor is diluted and the resulting wine will suffer. The acid is inversely proportional to the volume of liquor, so the steps in reducing acidity from 10 p.p.t., for example, to 7 p.p.t., are: (1) 7 / 10 = 0.70 (2) 100 / 0.70 = 1.428 (3) 1.428 x 128 (oz. per gallon) = 182.784 total oz. required (4) 182.784 (total required) - 128 (oz. per gallon) = 54.784 (oz. per gallon required to be added).