Winemaking Goes Beyond Vinifera

Winemaking Goes Beyond ViniferaA great synopsis of the whole fruit winemaking industry. This will make you understand the basic process of fruitwinemaking and the growing industry behind it.

Written by Alison Crowe:

Humankind has been producing alcoholic beverages from fruit for perhaps 10,000 years. Though most people think of grapes when they think of wine, most of the states and provinces of North America have commercial wineries that make fruit wines or, at the very least, grape wines flavored with fruit essences or concentrates. The vast majority of these wineries are in Canada, British Columbia, or the East Coast and the Midwest of the United States, places where the traditional vitis vinifera wine grapes don’t grow well. Rather than lamenting what they can’t have, many fruit wine producers celebrate their unique local offerings. Michigan is known regionally for its cherry wines, while the island of Maui is home to Tedeschi Vineyards, which puts out a successful and nationally distributed line of exotic pineapple-based wines.


Obtain Stability and Balance Through Careful Must Adjustment

Though all fruits will spontaneously ferment to some degree under the right conditions, there’s a reason “fruit wine” really means “wine made from fruit other than grapes.” When asked why vitis vinifera won the world winemaking race, Dr. James Lapsley, wine historian and associate professor at the UC Davis Department of Viticulture and Enology explains, “Vinifera is unique in fruits in developing as much sugar as it does, thus resulting in a wine of 10-14% alcohol, which is more stable. Ripe pineapple, for instance, is about 15% sugar. Thus most fruits need sugar additions, or water additions (to reduce acidity) or both. Vinifera makes itself, and thus became the standard.” Commercial fruit winemaking, by default, has largely become a quest for stability and balance, interventionist rather than self-inventing.

One of the first battles any fruit winemaker wages is with the sugar content of the juice or must. Depending upon the pH of the starting material, for a wine to have enough alcohol to be microbially stable as well as have the right texture in the mouth, winemakers shoot for at least 11.0% ethanol. Depending upon the sugar-alcohol conversion factor utilized (0.538 is a general starting point), that would require an initial sugar content of 20.45 %. Many fruits can barely top out at 12.0% (be careful of pulpy suspended solids in any hydrometer reading—it is best to centrifuge samples). With numbers like those, it quickly becomes evident that adding sucrose, honey, concentrate, or some other form of fermentable sugar is necessary.

What a producer is willing to add to a wine depends upon their stylistic goals. A Japanese study reviewed in the American Journal of Enology and Viticulture (vol 46 no. 1 1995) suggests that fruit wines sweetened with glucose and fructose, as is found in grape juice and fruit concentrates, scored higher in taste panels than the same fruit wine sweetened by un-cleaved sucrose. Some winemakers enjoy the bouquet and extra body that certain kinds of honey contribute to a product while some only sweeten their wines with same-fruit concentrates. Others simply skirt the sugar-addition issue by adding grape or other fruit brandy to their fruit wines to bump up the alcohol content.

What a producer can add to a wine depends on their federal and state laws and will affect how they eventually label the bottled product. For fruit winemakers in the U.S., TTB regulation group 27CFR4, listed at www.ttb.gov/regulations, is required reading. Ameliorate with a little bit of the “wrong” thing and all of a sudden an Upstate New York Pink Lady Apple Wine will have to be labeled as “Fruit Wine with Natural Flavors.”
Getting the acid balance right is the next challenge. The goal is to match the level of acid to the finished wine style (sweet, dry, or fortified) while maintaining enough acid for microbial stability and color stability, where applicable. There’s nothing wrong with having a pH of 2.93 and a TA of 9.75 g/L in a raspberry dessert wine with 7% residual sugar. The same final wine chemistry, in a dry apple wine, however, would be screamingly tart and the wine would be unbalanced and unpleasant to drink. The flip side is equally dangerous. Low-acid musts (pH’s over 3.80 and TA’s below 5.0 g/L for example) can lead to bacterial invasion, stuck fermentations, high volatile acidity, a flat taste profile, greasy mouthfeel, poor color, and a shortened shelf life.

Most winemakers combat low acid musts by adding tartaric, citric, malic acid, or a combination of all three. Check your federal and state/province regulations to make sure you are in compliance with laws in your area. High acid musts are sometimes de-acidified using calcium or potassium carbonate but often then are simply diluted with water and have sugar added back to the desired fermentation level. In the United States, winemakers can add water up to 35%. For cripplingly acidic fruit musts with total acidities over 20.0 g/L, like those made from gooseberries and loganberries,
winemakers may add up to 60% of the original volume as water.

Such drastic dilution can be a problem as it washes out not only flavor and color but also nutrients like nitrogen and amino acids which are critical for healthy fermentations. V.vinifera winemakers are fortunate in that they typically only have to supplement with nutrients like DAP in the realm of 1-2 lbs/K gallons, whereas fruit winemakers, to make up for natural deficits as well as any reduction due to dilution, often have to approach the legal limit when making nutrient adds. Tannins, coloring agents, and mouthfeel-enhancers like gum Arabic or mannoproteins also form part of the fruit winemaker’s tool kit. In order to minimize the use of additives, as well as to balance out sugar and acid levels, many fruit winemakers add a significant portion of grape juice concentrate to musts. This works very well for strongly-flavored fruit wines like elderberry, where a red V.vinifera concentrate can dilute the overbearing elderberry flavor while adding a balanced combination of sugars, acids, nutrients, anthocyanins, and tannin.

One advantage fruit wines enjoy over most grape wines is that due to their generally low phenolic and tannin content, they don’t need much time to age and can be out in the marketplace in a very short time. Three months from crusher to bottle is not unheard of. If a winery uses frozen fruit, or otherwise has a year-round supply, it can turn its tanks over multiple times and maximize the return on its equipment investment in the course of a year. Many wineries actually prefer to use frozen fruit, as the freezing process lyses cell walls, allowing for easier draining and pressing.

Overcoming Processing Challenges in the Cellar

Unfortunately, sometimes grape winemaking equipment isn’t good at handling the peels, pits, seeds, and pulp of other fruit. Stone fruits, in particular, can be difficult to work with and often winemakers are forced to do a lot of hard work by hand. Peaches, apricots, and plums require equipment like a pulper/finisher in order to process any kind of bulk tonnage. Though considered “exotic” equipment by grape winemaking standards, this kind of equipment is common in the food processing industry and can even be found used in industry publications and on the internet.
Pressing can be a problem in the cellar, especially for pulpy fruits, fruit with tiny seeds, or fruit that completely breaks down in the fermentor. Employing 50 lbs
or more of rice hulls per ton is sometimes necessary if using a standard grape-winemaking bladder or tank press. Of further help are large mesh or cloth bags which are filled with a must and rice hull mixture and then pressed. The mesh acts as a fine strainer for the emerging wine while the rice hulls nicely break up the solids inside the bag and keep the cloth from fouling. Pressing should be long and gentle, with minimal rotations because the tannins and polyphenols expressed in hard-press wine from fruit, especially that with seeds, can be particularly bitter. Just like in grape winemaking, it’s important to evaluate any medium to hard-press wine before re-incorporating it in the blend.

High pectin content (and the resultant hazes and settling issues) is also a problem for most fruits so pectolytic enzymes should be a part of every fruit winemaker’s arsenal. Dosage rates required for fruit wines are typically far and above that of recommended levels for grape juice and wine use, so check with the manufacturer’s literature for addition suggestions as well as the legal limits. Look for enzymes with a high pectin lyase content or those that have good activity at low pH’s and use them only in pressed juice or wine. Enzymes cut viscosity, aid in settling and help compact lees when they do settle. Keep in mind that high levels of SO2 or alcohol and low temperatures can inhibit enzyme activity.

In aging, racking, and filtration, fruit wines behave very much the same as grape wines. Though high sugar content will contribute to viscosity, dry fruit wines take very well to pad or diatomaceous earth filtration. Since many fruit wines have very high malic acid levels, it is usually recommended to filter fruit wines to a 0.45 micron nominal-sterile level. Bulk and bottle aging times before release are typically short, and many products won’t age well over time. Bargetto Winery near Santa Cruz, CA, producer of a successful line of mead and fruit wines called Chaucer’s, even puts the following disclaimer about their Olallieberry wine on their website, “This specialty dessert-style beverage is not fortified and contains only 10.5% alcohol. Hence, this wine should be consumed shortly after purchase to enjoy its natural and rich fruit flavor.” Sweet, fortified fruit wines with alcohols over 16% age fairly well and can last for at least five years in the bottle.

A Selection of Fruit for Winemaking

The aspiring fruit winemaker has many choices when it comes to selecting a starting material. Just about any fruit (except citrus, which tend to be too acidic) lends itself well to winemaking, with some basic must adjustments.

Apples:The two most important things to remember when using apples to make wine are that they brown exceedingly easily and that they contain a lot of pectin. The first problem can be mitigated by starting with only sound fruit and by distributing a solution of 100-150 g of malic acid and potassium metabisulfite (KMS or KMBS) per ton of fruit crushed. It is critical that apples be fermented as a juice—quick pressing will help separate the browning pulp from the liquid. The addition of a pectic enzyme in the press pan or the juice-reception tank will assist in settling and help prevent haze later on. As with any juice or must for winemaking, perform the usual brix, pH, TA, amino nitrogen, ammonia, and malic acid analyses. Apple juice often needs to have sugar added to it if an alcohol over 6% is desired and, like many fruits, can be deficient in nutrients critical for a healthy fermentation. For the rest of the process, fermenting, racking, and storing are much like standard white winemaking practices.

Blueberries:Though not as easy to grow or as ubiquitous as apples, blueberries make very good wines, which, because of the tannins and polyphenolics found in the skins, can approach the structure, texture, and balance of what a drinker expects from a red V. vinifera wine.
Blueberries have low sugar and high acid, necessitating some serious amelioration to produce a balanced, stable beverage over 10% alcohol. 7-9% sugar, TA of 10 g/L and pH’s dipping below 2.90 are common initial must stats. For winemaking, the best fruit is very ripe, which sometimes can be had in the form of culls from commercial growers and packers, who will usually part with their bruised fruit for a reduced price. In processing, a winemaker must use pectolytic enzymes and if using only blueberries (and not a significant portion of grape juice or concentrate), careful attention must be given to juice nutrition. Blueberry wine is one of the few fruit wines that can benefit from any significant aging in oak barrels.

Bramble Berries: Bramble fruits, those which grow on thorny bushes, are widespread over the North American continent and include Rubus idacus (raspberry), Rubus laciniatus (cutleaf blackberry) and Rubus ursinus, the invasive wild blackberry. Much prized by winemakers for their bright color and attractive flavors, Rubus fruits are relatively easy to grow though purchasing “domesticated” cultivars from a nursery is recommended in order to avoid having wild bushes run rampant.
From a winemaking point of view, bramble berries present many challenges. They are naturally low in sugar and are very high in acid so require expert amelioration to target the needs of the desired finished product. They also must be pressed inside mesh bags or over fine stainless screens as they have tiny seeds. Unfortified bramble wines with alcohols under 14% are very susceptible to VA, so headspace and sulfur dioxide levels must be managed carefully. Style-wise, many winemakers prefer to keep bramble berry wines from going through any malo-lactic fermentation and so sterile filter before bottling.

Stone Fruits:The stone, or drupe, fruits include peaches, apricots, plums, and cherries. Peaches are often found in distilled products as well as cider-type sparkling wines and lower-alcohol beer-style ciders. Northern California’s Japanese community has developed numerous types of “plum wine,” enjoyed as an aperitif as well as taken as a health tonic. An excellent example of this style of beverage, not a true plum wine but a white grape or sake wine flavored with plum essence, is made by Takara Sake, USA, in Berkeley, California.

Though sugar and acid levels in stone fruits can be quite balanced, a little amelioration is often needed. Many of the stone fruits, especially peaches, are prone to hydrogen sulfide development during fermentation, due most likely to low natural nitrogen and amino acid content. Another possible cause of H2S development is the sludgy nature of the must. Stirring or agitating the must as it ferments is a good way to avoid reductive “dead zones” at the bottom of the fermentor during the slow last stages of -fermentation.

Fruit Wine Sector Remains Small but Could Grow if Overall Wine Consumption Keeps Increasing

Worldwide, it’s unlikely that fruit wines will ever approach the production volume, or even the perceived quality, of grape wine. In 1998, a winespectator.com survey presented website visitors with the following scenario: “Berries and fruits are ripening, tempting amateur and professional winemakers to try fermenting them. But is the finished product worth it? Or should winemakers stick to using grapes?” Perhaps given the audience, a not-surprising majority (60.7%) of respondents thought that wine should only be made from grapes. When recently asked if UC Davis, one of the top agricultural universities in the world, currently devotes any funding to or teaches any classes about fruit wines, Dr. Andrew Waterhouse, professor in the Department of Viticulture and Enology, reports, “No. The commercial market in California is too small to justify.”

Nevertheless, winemakers keep experimenting and increasingly non-brand-loyal customers keep trying new products. It’s old news that adventure brands like T
hree Thieves and “critter” brands like Yellowtail have piqued the interest of many former beer and liquor drinkers. With their already forward-looking packaging (many fruit winemakers switched to screwcaps years before they were considered cool for table wines) producers like St. Julian in Michigan might have a chance to catch the eye of these fledgling wine drinkers.

But tough as it is for vinifera wines to get a foothold in today’s consolidation-rife market, fruit wineries might try the “drink locally” angle and take advantage of a consumer culture that is becoming more aware of and appreciative of where food and drink come from. When asked how he thought fruit wineries could make inroads into the marketplace, Brent Trela, former professional fruit winemaker and now director of Distance Education in Winemaking at UC Davis comments, “I think regional producers can find a niche for their products, especially for markets that promote regional products or those that support local consumption of local products.”

Grape and wine industry analysts see wine consumption rising in North America over the next few years while grape planting is slowing down and there are fewer and fewer bearing vineyards coming on line every season. It’s clear that imports from places like Spain, Australia, and South America will supply part of that demand, but it also could be a good opportunity for fruit winemakers to take advantage of a thirsty and increasingly curious consumer base. When asked how sales were doing at his u-pick orchard-turned-winery in Alberta, Canada, Marvin Gill, owner of Fieldstone Fruit Winery, replied, “Fruit wine sales are increasing at about 30% a year across Canada, so if this trend continues it is very positive for the fruit wine industry.”

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