Muscadine: A taste of the South

I’ll just have to begin this column with the statement, “I had no idea!” A few years ago, an attendee to one of my Step-by-Step Winemaking classes offered through UC-Davis mentioned that he had some plantings of Muscadine on his property in the Napa Valley. The concept seemed odd to me at the time. I mean, here he is in the middle of California’s most notable wine-producing region, and he is growing Muscadine! Skip ahead to my deadline for this article and I start doing my research. My favorite resources are the websites of the local universities and cooperative extensions for the regions where specific varieties are grown. While this is strictly a qualitative assessment, I found more academic-based information on the Muscadine variety on my first search page than I would find with a search for any Vitis vinifera variety. This Native American grape is a versatile fruit that is suited best for the hotter regions in which it is grown. Not only is it made into wine, but Muscadine finds its way into the culinary world as well. Those who embrace the Muscadine grape are a very enthusiastic bunch!

Muscadines are vigorous vines that are native to the southeastern United States, ranging from Texas to the Carolinas. It flourishes in full sun and hot climates. It has a non-shedding bark with a warty appearance. The leaves are slightly lobed, glossy, dark green above and yellow below. Most Musca-dines are dioecious, which refers to the fact that the male and female parts are on different plants and they are pollinated through wind and insects. For the dioecious varieties, the male plants must be planted close to the females for pollination and berry development. In a trellised vineyard, there needs to be a male plant among about every three to four female plants. Selective plant breeding has produced some self-pollinating cultivars.

The fruit develops in loose clusters. Some clusters have as few as three berries, but can range up to 20 berries per cluster. Color of the fruit can range from bronze to almost black depending on the variety. The skin of the berry is very thick, and there is an underlying membrane holding a gelatinous inner pulp that reminds me of a fish eye after the fish has been barbequed. The visual here is that of a fish, cooked whole, and someone pressing on the eyeball. The inner part pops out, hence my designation “fish-eye” grapes. The sugars at maturation range anywhere from 16 to 25 °Brix. The fruit tends to ripen unevenly within the vines, and individual berry harvests are under-taken to get the fruit off the vine at optimal maturity and ripeness. This can be a very labor intensive process requiring multiple passes through the vineyard at harvest time. One positive quality of the fruit is that when the fruit is ready for harvest, it tends to drop from the vine. Trellis vines can be harvested similar to other orchard crops by placing a ground cloth below the vine and shaking it.

Muscadines are vigorous vines that are native to the southeastern United States, ranging from Texas to the Carolinas.

The mature fruit falls to the cloth and can be collected for processing. However, even the experts will further sort the fruit at this point. The flavors of the grape can take on the muskiness that is associated with many Native American grapes, but breeders have been working to reduce that quality and bring out more fresh fruit characters.

With respect to taxonomy, all grapes belong to the Vitaceae family. Taxonomists are busy people, constantly debating how particular species need to be classified. This is not just limited to plant taxonomists, but all across all kingdoms including animal, plant, and fungal. When I first learned of Muscadine, it was its own separate genus and species, Muscadinia rotundifolia. Vitis vinifera is the more common genus and species of grape used for winemaking. Common examples of V. vinifera varieties include Chardonnay, Cabernet Sauvignon, or Pinot Noir. The genus Vitis now encompasses all grapes. Other Native American grapes such as Summer Grape (V. aestivalis), California Grape (V. californica), American Grape, Fox Grape (V. labrusca), River Bank Grape (V. riparia), and Sand Grape (V. rupestris) are all distinct enough to support their own species designation. But the Muscadines, now formally known as V. rotundifolia, needed to be further classified in to a sub-genus, Muscadinia. The Muscadines have varieties as well. Scuppernong, Black Beauty, and Sweet Jenny are some examples of the over three hundred known varieties of Muscadine. The growth habits of all Vitis species are the main characteristics that classify them as such. Looking at a Muscadine vine, how can one not think of it as a grape; therefore the Vitis connection. However, Muscadines differ most from their Vitis counterparts in that they do not make up the same number of chromosome pairs. Muscadine grapes count 40 pairs of chromosomes; the other Vitis species count 38 pairs. This makes Muscadines and other Vitis species unable to cross breed naturally. Plant breeders have tried to cross Muscadines with vinifera, which resulted in primarily sterile progeny.

In addition to breeding Muscadines to improve fruit quality, plant breeders cross breed Vitis species with Muscadines because of the disease-resistance capabilities it has. Muscadines are naturally resistant to Pierce’s Disease (PD), phylloxera, and nematodes. PD is a condition caused by the bacterium Xylella fastidiosa, which is vectored by various insect species, most commonly the glassy-winged sharpshooter. PD is fatal to the vine, and all cultivars of V. vinifera are susceptible to PD. Breeders have been successful in recent years in developing PD-resistant varieties, while still extolling the qualities of vinifera in the resulting progeny. V. rotundifolia has played a relatively minor role in the development of rootstocks that are phylloxera-resistant. Grafts of V. vinifera with Muscadines have been used, but the compatibility issues make this a less desired approach. Therefore, V. rupestris and V. riparia have been the more desired combinations for rootstock development.

Some wineries purport the beneficial health effects of Muscadine wines, in that their thick skins and pulp are rich in phenolic compounds. One report even went so far as to say that the Muscadine was a smarter grape because of the extra set of chromosomes it contains. If this was true, then humans must not be that much smarter because we only have 46 chromosomes! And then there’s the potato with its just slightly smarter quantity of 48. But then we see that the high and mighty domesticated chicken is over twice as smart with 78! The next time I grill up some chicken I’ll remember that Foster Farms commercial.

What real research shows is that plant-derived phenolic compounds, also referred to as phytochemicals in the literature, in general, are strong antioxidants and do everything from boosting immune system function, preventing cancer, and improve liver performance. The underlying premise of all this research is that a balanced diet, consisting of fruit, vegetables, and moderate consumption of wine, may result in a decreased risk for cancer and better immune system performance. The notion that the Muscadine wines are better than any other wine or lifestyle choice is entirely false. A study from the University of Florida begins with the statement, “This publication is a summary of the health benefits that can be derived from consuming Muscadine and other red wine. Muscadine wine contains a high level and unique variety of antioxidants which appears to prevent detrimental effects to the immune system caused by alcohol”.

The study then continues to detail the various phenolic components during specific steps in the maceration process. The results of such scientific work can be found in research notes of other varieties as well. In test tube experiments, the high levels of polyphenolic activity are well documented. One thing to note with these in vitro studies is that not all the experimental models are the same, and they are generally based on the ability to scavenge oxygen. Depending on the co-factors used too, the reactions can proceed at different rates amongst the same compounds. However, Muscadines are shown to have a high oxygen or radical scavenging rate.

Muscadines are well known in the kitchen. Preserves, compotes, pies and dried fruit preparations are common. A recent episode of the PBS documentary/ reality show The Chef’s Life focused on the many faces of Muscadines. In the kitchen, there was the seemingly painstaking process of juicing the berries and removing the seeds.

The first was a pizza made with a Muscadine-based sauce with red onions, blue cheese and bacon. This combination melds the sweetness of the grape with the savoriness of the onion and bacon, and a little saltiness from the cheese and bacon; the pizza was a hit with the customers. For dessert, they made a buttermilk panna cotta served with Muscadine preserves. I was a little disappointed in that they didn’t serve the dessert with a sweeter version of the Muscadine wine.

The wines of Muscadine have been made for over 400 years, since the first explorers arrived in North America. The styles range from sweet to dry with a wide range of flavor profiles. Harvesting the grapes is a laborious task, often one berry at a time. The grapes are selected by color and sweetness. Once in the winery, the individual berries are crushed and placed in the tank for fermentation. Chaptalization, or the addition of sugar, seems to be the norm with most preparations I reviewed. One recipe I came across even included heating the must on the stove. They didn’t boil the must, but they heated it to the point where steam was just becoming visible. This makes sense to me, from a scientific standpoint, because heating musts can improve color extraction and stability. It also seemed to aid in getting the sugar integrated into the must.

In discussions with Muscadine winemakers, sweeter examples are made by arresting the fermentations either through dropping the temperature or adding sulfur dioxide and potassium sorbate. With the high phenolic content of the grapes, long skin contact times can lead to high bitterness and astringency. Color development and sugar amelioration can be achieved by the addition of Mega Purple or other grape juice concentrates. For even more tips on making Muscadine wines — from growing the grapes through aging — check out the Muscadine roundtable story from the April-May 2010 issue of WineMaker, which includes insight from four commericial winemakers from the south.

The ideas I had no clue of when I began the research for this article are now becoming apparent. This is a versatile grape that belongs in a “love it or hate it” class. What I was really impressed with was its local use in the Farm to Fork movement that seems to be popping up all over America. Who is better to know the strengths of this versatile grape than the locals who have incorporated it into the local custom and traditions? I didn’t ask my former student where he was from. In the end it was a little presumptuous of me to react in the way that I did. But the Muscadine in his life was likely of the Muscadine he grew up with. I’ll never know, but I certainly have developed an appreciation for this grape.

Muscadine Recipe (5 gallons/19 L)

• 75 pounds (34 kg) fresh Muscadine fruit (Pick your favorite, the information I found did not discriminate the actual type and they all seemed to process the same.)
• Distilled water
• Corn sugar – Prepare a ~50 °Brix solution (later called the “high Brix” solution. Weigh 1.9 kilograms of corn sugar and dissolve into 1 gallon (4 L) of distilled water. Measure the actual Brix here, but it should be around 50 °B.
• 10% potassium metabisulfite (KMBS) solution. Weigh 10 grams of KMBS, dissolve into about 50 milliliters (mL) of distilled water. When completely dissolved, make up to 100 mL total with distilled water.
• 5 grams EC1118 yeast
• 5 grams Di-ammonium Phosphate (DAP)
• 5 grams Go-Ferm
• 5 grams Fermaid K (or equivalent yeast nutrient)

Other equipment or needs
• 15-gallon (57-L) food-grade plastic bucket for fermentation.
• 5-gallon (19-L) carboy
• (1–2) one-gallon (4-L) jugs
• Airlocks
• Racking hoses
• Crush equipment (You just want the ability to crush the grapes. You could even use your hands.)
• Wine press/strainer to separate the skins and the seeds from the juice.
• Inert gas (nitrogen, argon or carbon dioxide)
• Ability to maintain a fermentation temperature of 81–86 °F (27–32 °C).
• Ability to chill the carboy to 32–38 °F (0–3 °C).
• Thermometer capable of measuring between 32–110 °F (0–43 °C) in one degree increments.
• Pipettes with the ability to add in increments of 1 mL.

Step by step
1. Clean and sanitize all your winemaking tools, supplies and equipment.

2. Crush the grapes. Transfer the must to your fermenter.

3. During the transfer, mix in 15 mL of 10% KMBS solution (This addition is the equivalent of 50 ppm SO2).

4. Take a sample to test for Brix. Keep the results handy. We’ll use this later.

5. Layer the headspace with inert gas and keep covered. Keep in a cool place overnight.

6. Calculate how much sugar to add. Use this handy calculator at http://vinoenology.com/calculators/chaptalization-and-water-dilution/. Enter your starting volume, the initial Brix, and the desired final Brix, and then use the Brix value for your high Brix solution you prepared earlier. The calculator will return the volume of your sugar solution to add. For example, I entered 4 gallons (15 L) to start, a 15 °B initial value, and a desired final Brix of 22. The volume of high Brix sugar solution to use was exactly 1 gallon (4 L), so I now have 5 gallons (19 L) of must. You make the decision of how much sugar to add based on your desired final alcohol.

7. The next day, sprinkle the Fermaid K directly on the must and mix well.

8. Prepare yeast. Heat about 50 mL distilled water to 108 °F (42 °C). Mix the Go-Ferm into the water to make a suspension. Take the temperature. Pitch the yeast when the suspension is 104 °F (40 °C). Sprinkle the yeast on the surface and gently mix so that no clumps exist. Let sit for 15 minutes undisturbed. Measure the temperature of the yeast suspension and the must. You do not want to add the yeast to your cool juice if the difference in temperature exceeds 15 °F (8 °C). To avoid temperature shock, you should acclimate your yeast by taking about 10 mL of the must juice and adding it to the yeast suspension. Wait 15 minutes and measure the temperature again. Do this until you are within the specified temperature range. Do not let the yeast sit in the original water suspension for longer than 20 minutes.

9. When the yeast is ready, add it to the fermenter and mix.

10. You should see signs of fermentation within one to two days. This will appear as some foaming on the must surface and it will appear that the berries are rising out of the medium. This is referred to as the “cap rise.”

11. Push the grapes back into the juice to promote color, and tannin extraction three times per day. Use a clean utensil or your hand to mix. This is called “punching down.”

12. After 3 days, separate the skins and the seeds from the juice using the press or strainer. Limiting the skin and seed contact can reduce any bitterness or astringency.

13. Monitor the Brix and temperature twice daily during peak fermentation (10–21 °Brix). You want to keep the temperature from 81-86 °F (27–30 °C). Placing frozen, sanitized water botles in the must is an easy way to bring down the temperature if needed.

14. At about 1⁄3 °Brix depletion, sprinkle in the DAP and mix.

15. If you want to leave the wine a little sweet, taste daily and when you have the desired sweetness, start chilling the fermentation. Transfer the wine to your carboy. Add 4 mL of fresh KMBS per gallon of wine and get the carboy in the refrigerator at the coldest setting. Label your vessels to keep the press portion separate!

16. If you want to make a dry wine, continue the fermentation until no signs of gas evolution are present. Then add 2 mL of fresh KMBS per gallon (4 L) of wine and get the carboy in the refrigerator at the coldest setting.

17. Make sure you do not have any head space. Transfer the wine to smaller carboys or one-gallon (4-L) jugs. Label the vessels.

18. Allow the wine to chill in the refrigerator. After two weeks, test for SO2 and adjust as necessary to attain 0.8 ppm molecular SO2. (There is a simple SO2 calculator at www.winemakermag.com). Check the SO2 in another two weeks and adjust. Once the free SO2 is adjusted, maintain at this level. Check every two months or so, and before racking.

19. Rack the wine clean twice over 6-8 month timeframe to clarify.

20. Filtration is generally not needed if SO2 levels are maintained.

21. Maintain sanitary conditions while bottling.