Ice wine (or icewine; German Eiswein) is a type of dessert wine produced from grapes that have been frozen while still on the vine. The sugars and other dissolved solids do not freeze, but the water does, allowing a more concentrated grape must to be pressed from the frozen grapes, resulting in a smaller amount of more concentrated, very sweet wine. With ice wines, the freezing happens before the fermentation, not afterwards. Unlike the grapes from which other dessert wines, such as Sauternes, Tokaji, or Trockenbeerenauslese, are made, ice wine grapes should not be affected by Botrytis cinerea or noble rot, at least not to any great degree. Only healthy grapes keep in good shape until the opportunity arises for an ice wine harvest, which in extreme cases can occur after the New Year, on a northern hemisphere calendar. This gives ice wine its characteristic refreshing sweetness balanced by high acidity. When the grapes are free of Botrytis, they are said to come in "clean".
Due to the labour-intense and risky production process resulting in relatively small amounts of wine, ice wines are generally quite expensive.
Canada and Germany are the world's largest producers of ice wines. About 75 percent of the ice wine in Canada comes from Ontario.
There is also a sparkling version of ice wine. Sparkling ice wine was created accidentally in 1988, by Canadian wine writer, Konrad Ejbich, in his home cellar , using tank samples of the previous year's ice wine, from the Inniskillin winery in Ontario. In 1996, finally acknowledging he could not produce this product himself on a commercial basis, Ejbich decided to share the concept. He wrote about his experience with sparkling ice wine in his column in Wine Tidings magazine, challenging Canadian wineries to make sparkling ice wine on a commercial basis. The Magnotta winery in Ontario filled a 50-litre metal beer barrel with ice wine, carbonated it, and called their product the first commercial sparkling ice wine. However, Ontario's Vintner's Quality Alliance (VQA) would not give the product its stamp of approval because no such category existed in its regulations. In 1998, Inniskillin Wines produced the first charmat method sparkling ice wine. The VQA approved Inniskillin's product because it was not made using carbonation. Today, several Canadian wineries (in Ontario and British Columbia) produce sparkling ice wine, to growing international acclaim.
There are indications that frozen grapes were used to make wine already in Roman times.Pliny the Elder (AD 23 - 79) wrote about certain grape varieties that they were not harvested before frost has occurred. The poet Martial (AD 40 - 102) recommended that grapes should be left on the vine until November or until they were stiff with frost. Details as to the winemaking and description of these wines are unknown. It can not be completely ruled out that the descriptions refer to dried grape wines, a common style of wine in Roman times, where the raisin-like grapes were harvested late enough for the first frost to have fallen. In either case, the method seems later to have been forgotten.
It is believed that the first post-Roman ice wine was made in Franconia in Germany in 1794. Better documentation exists for an ice wine harvest in Dromersheim close to Bingen in Rheinhessen on February 11, 1830. The grapes were of the 1829 vintage. That winter was harsh and some wine-growers had the idea to leave grapes hanging on the vine for use as animal fodder. When it was noticed that these grapes yielded very sweet must, they were pressed and an ice wine was produced. It should be noted that sweet wines produced from late harvested grapes were well-established as the most valued German wine style by the early 19th century, following the discovery of Spatlese at Schloss Johannisberg in Rheingau in 1775, and the subsequent introduction of the Auslese designation. These wines would usually be produced from grapes affected by noble rot. Thus, Eiswein is a more recent German wine style than the botrytised wines.
Throughout the 19th century and until 1960, Eiswein harvests were a rare occurrence in Germany. Only six 19th century vintages with Eiswein harvests have been documented, including 1858, the first Eiswein at Schloss Johannisberg. There seem to have been little effort to systematically produce these wines during this period, and their production was probably the rare result of freak weather conditions. It was the invention of the pneumatic bladder press which made the production of ice wine practical and led to a substantial increase in the frequency and quantity of production. 1961 saw the production of a number of German ice wines, and the wine increased in popularity in the following years. The production has also been assisted by other technological inventions in the form of electrical lighting driven by portable generators (to assist harvest in the cold hours of morning darkness, before the grapes thaw) and plastic films that are used for "packaging" the vines in order to protect the ripe grapes from being eaten by birds when the wine-grower waits for frost.
The pioneer status of the winery Inniskillin in Niagara-on-the-Lake, Ontario has led to their first ice wine, produced in 1984 under the direction of the winery's Austrian-born co-owner Karl Kaiser, often being mentioned as Canada's first ice wine. However, ice wine was produced in the Okanagan Valley of British Columbia by German immigrant Walter Hainle already in 1972. This ice wine was the result of an early and unexpected frost and yielded 40 litres of wine, which Hainle originally did not intend to sell, although he did so in 1978. In 1983, Karl Kaiser and Inniskillin's German neighbour Ewald Reif, as well as two wineries with Austrian winemakers located in another part of Ontario, Hillebrand and Pelee Island, all left grapes on their vines in order to try to produce ice wine. Inniskillin and Reif lost their entire crop to hungry birds, while Hillebrand and Pelee Island were able to harvest a minuscule amount of frozen grapes. In 1984, Kaiser used nets to protect his vines and was able to produce Inniskillin's first ice wine. This wine was made from Vidal grapes and was, in fact, labelled "Eiswein."
After the ice wine production was set on commercial footing, Canadian ice wine quickly became popular with domestic consumers and reviewers, and many other Canadian producers and regions picked up the idea, since the harsh Canadian winters lend themselves well to the large-scale production. The international breakthrough of Canadian ice wine came in 1991, when Inniskillin's 1989 Vidal ice wine won the Grand Prix d’Honneur at Vinexpo. The Canadian trend towards increased cultivation of Vitis vinifera (European) grape varieties in the 1990s expanded the palette of varieties available to be bitten by frost. By the early 2000s, Canada was established as the largest producer of ice wine in the world.
In Germany in the early 2000s, good ice wine vintages have been more rare than throughout the 1980s and 1990s. Many wine-growers cite climate change as a cause, and this received support from a study by the Geisenheim Institute.
Ice wine producers
The most famous (and expensive) ice wines are German Eiswein and Canadian Icewine (where the name is written as one word), but ice wine is also made in Australia, Austria, Croatia, Czech Republic, France, Hong Kong, Hungary, Israel, Italy, Luxembourg, New Zealand, Slovakia, Slovenia, Sweden and United States, at least in smaller quantity. Eiswein is part of the Pradikatswein quality category in the German wine classification, and Icewine in Canada must follow VQA protocol to be labelled as such. The French language term Vin de glace is part of the wine classification in Luxembourg, but not in France, but is sometimes found on the rare bottles of ice wine produced in Alsace.
In contrast to most other wine-producing regions, Canada, particularly the Niagara Peninsula, consistently undergoes freezing in winter and has become the world's largest ice wine producer. Icewine production in Canada is regulated by the Vintners Quality Alliance in the provinces of British Columbia and Ontario. If the sugar level in the grapes measures less than 35° Brix, then they may not be used for icewine, a minimum considerably higher than that of German Eiswein. These grapes are often downgraded to a lower designation, such as Special Select Late Harvest or Select Late Harvest. Canadian rules were further tightened in British Columbia in 2000 after a producer dealt with the mild winter of 1999 by moving grapes up to the mountains to seek freezing temperatures.
Though Pelee Island Winery and Hillebrand were Canada's first commercial icewine producers, starting production in 1983, Inniskillin Wines is considered the most widely known Canadian icewine producer as the first Canadian winery to win a major international award, the Grand Prix d’Honneur at 1991 Vinexpo in France, with their 1989 Vidal Icewine (which was technically an illegal import into the EU), placing Canadian icewines on the world stage. Pillitteri Estates Winery has emerged in the 2000s as the world’s largest estate icewine producer. In November 2006 the Canadian producer Royal DeMaria released five cases of Chardonnay icewine with a half-bottle price set at C$ 30,000, making it the world's most expensively priced wine.
Natural ice wines require a hard freeze (by law in Canada −8 °C (17 °F) or colder, and in Germany −7 °C (19 °F) or colder), to occur sometime after the grapes are ripe, which means that the grapes may hang on the vine for several months following the normal harvest. If a freeze does not come quickly enough, the grapes may rot and the crop will be lost. If the freeze is too severe, no juice can be extracted. Vineland Winery in Ontario once broke their pneumatic press in the 1990s while pressing the frozen grapes because they were too hard (the temperature was close to −20 °C). The longer the harvest is delayed, the more fruit will be lost to wild animals and dropped fruit. Since the fruit must be pressed while it is still frozen, pickers often must work at night or very early in the morning, harvesting the grapes within a few hours, while cellar workers must work in unheated spaces.
In Austria, Germany, and Canada, the grapes must freeze naturally to be called ice wine. In other countries, some winemakers use cryoextraction (that is, mechanical freezing) to simulate the effect of a frost and typically do not leave the grapes to hang for extended periods as is done with natural ice wines. These non-traditional ice wines are sometimes referred to as "icebox wines". An example is Bonny Doon's Vin de Glaciere or King Estate's Vin Glace (made from Oregon Pinot Gris grapes).
The high sugar level in the must leads to a slower-than-normal fermentation. It may take months to complete the fermentation (compared to days or weeks for regular wines) and special strains of yeasts should be used. Because of the lower yield of grape musts and the difficulty of processing, ice wines are significantly more expensive than table wines. They are often sold in half-bottle volume (375 ml) or the even smaller 200ml bottle. New World wineries in particular sometimes bottle 200 ml and 50 ml gift packages.
The minimum must weight requirements for ice wine is as follows, in the measures used in the respective country:
- For German Eiswein, 110 to 128 degrees Oechsle, the same as for Beerenauslese, depending on the region (wine growing zone) and grape variety.
- For Austrian Eiswein, 25 degrees KMW, the same as for Beerenauslese, corresponding to 125 °Oechsle.
- For Canadian Icewine, 35 degrees Brix.
- For Luxembourg Vin de glace, 120 °Oechsle.
Cryoextraction is the process by which grapes are frozen with refrigeration and pressed. Winemakers subject grapes to temperatures around 20 degrees Fahrenheit (or -7 degrees Celsius), and press them while still frozen. Ice crystals remain in the press, while concentrated juice flows out. The resulting wine resembles ice wine. The process of freeze distillation is similar in its concentrating effects, although it occurs after fermentation.
Typical grapes used for ice wine production are Riesling, considered to be the most noble variety by German winemakers; Vidal, highly popular in British Columbia and Ontario, Canada; and, interestingly, the red grape Cabernet Franc. Many vintners, especially from the New World, are experimenting with making ice wine from other varieties: whites such as Seyval Blanc, Chardonnay, Kerner, Gewurztraminer, Chenin Blanc, Pinot Blanc, and Ehrenfelser; or reds such as Merlot, Pinot Noir, and even Cabernet Sauvignon. Pillitteri Estates Winery from the Niagara-on-the-Lake region of Ontario claim to be the first winery in the world producing Shiraz (Syrah) ice wine with the 2004 vintage, Semillion, and Sangiovese in 2007.
Ice wines from white varieties tend to be pale yellow or light gold in color when they are young and can maderise (acquiring a deep amber-golden color) as they age. The red varieties tend to have a light burgundy or even pink color like that of rose wines.
Even though it is normal for residual sugar content in ice wine to run from 180 g/L up to as high as 320 g/L (with a mean in the 220 g/L range), ice wine is very refreshing (as opposed to cloying) due to high acidity. (The titratable acidity in ice wine is almost always above 10 g/L.) Ice wine usually has a medium to full body, with a long lingering finish. The nose is usually reminiscent of peach, pear, dried apricot, honey, citrus, figs, caramel, green apple, etc., depending on the varietal. The aroma of tropical and exotic fruits such as pineapple, mango, or lychee is quite common, especially on white varietals .
Ice wine usually has a slightly lower alcohol content than regular table wine. Some Riesling ice wines from Germany have an alcohol content as low as 6%. Ice wines produced in Canada usually have higher alcohol content, between eight and 13 percent. In most years, ice wines from Canada generally have higher brix degree (must weight) compared to those from Germany. This is largely due to the more consistent winters in Canada. Must with insufficient brix level cannot be made into ice wine, and is thus often sold as "special select late harvest" or "select late harvest" at a fraction of the price that true ice wine commands.
Connoisseurs argue about whether ice wine improves with age or is meant to be drunk young. Those who support aging claim that ice wine's very high sugar level (which is often much higher than that of Sauternes) and high acidity preserve the content for many years after bottling. Those who disagree contend that as ice wine ages it loses its distinctive acidity, fruitiness, aroma, and freshness.