Dessert wines can be red or white. The grapes can be fortified, frozen, left to rot on the vine, even turned into raisins before they are turned into wine. Some dessert wines just come from grape varieties that naturally have a higher sugar content. They are some of the longest living wines of the world and many have been made and praised by everyone from Royalty to Presidents. The methods of producing a dessert wine may vary but the end result is the same; you leave with a sweet taste in your mouth.
The easiest and most straight forward type of dessert wines are those made from grapes that are naturally higher in sugar content like the Muscat variety. Muscat is the parent to a huge family, some of the more famous ones being the Muscat Blanc à Petits Grains used to make the lightly fizzy Asti wine from Piedmont, Italy. The wine region of Rutherglen in Australia has a 4 tiered classification system for the sweet grape. Muscat even has it's place in sweet fortified wines like certain types of Sherry and French vin doux naturels. The aromas of Muscat range from citrus, rose and peach and for lack of a better word grape notes to fruit cake, raisins and toffee. They make great partners for citrus desserts.
Fortified wines like Port, Sherry, Marsala, and Madeira, have dominated the after dinner drink for centuries. The fortification is usually achieved by adding a neutral grape spirit to the wine that stops fermentation retaining the sugar in the wine and raises the alcohol level in it. The neutral grape spirit is typically a form of Brandy. Originally it was done as a way to preserve the wine for longer, which is why some of these wines can age for decades even centuries before losing their flavours. The grape varieties used are unique to each type, Port for example allows over 50 different grape varieties in its production. Each type of fortified wine also has many styles ranging from dry to sweet. The many options and styles can keep you experimenting with fortified wines for years, but there are other types of dessert wines not to be ignored.
A Late harvest wine, or Vendange Tardive in French, or Spätlese, and Auslese in German is a wine that is harvested late, very straight forward. However, once you leave a grape on the vine 2 things can happen to turn the wine into a sub-category of Late Harvest wine. They can develop a rot we elegantly label Noble rot, or they can freeze and become ice wine. The sweetness in all these wines is achieved by leaving the grapes on the vine past harvest time, the grapes then begin to dehydrate and concentrate the amount of sugar present in the grapes, thus giving you a sweeter wine. Riesling, Gewürztraminer, and Pinot Gris are typically the grapes you see used for late harvest wines. Each one with it's own unique characteristics, although most have a silky texture to them which makes them ideal with mousse, or puddings.
The Noble Rot known as Botrytis cinerea is the home category of the most famous dessert wine from Bordeaux, known as Sauternes, and Château D'Yquem is said to make the best. They use Sémillion and Sauvignon Blanc grapes that have been affected by the noble rot to produce their world class dessert wine, noted for it's honey and hazelnut characteristics. But it stands to note that Hungary was the first in the world to use the sweetened grapes of Furmint, Yellow Muscat, and Hárslevelü, in their dessert wine they Tokaji. This wine was praised and loved by everyone from Beethoven to Louis XIV. Tokaji holds historical relevance as the world's first appellation controlled region. Germany and Austria are also renowned for using grapes affected by noble rot, and has 2 categories that differentiate the amount of sweetness in the wine. They are known as Beerenauslese (BA) and Trockenbeerenauslese (TBA). With TBA being the sweeter of the two. The noble rot wines are great with rich desserts like cheesecake.
Ice wine first made in Germany where it is known as Eiswein is what brought Canada fame on the international wine stage. It is made by leaving the grapes on the vine well past typical harvest time and allowing them to freeze. The juice freezes in the grape concentrating the sugars giving you a sweet wine. By law the temperature must reach -8º C (17ºF) before the harvest of Ice wine is allowed to commence. Typically the harvest is done at night to ensure the temperature stays cool. Making Ice Wine is fraught with many potential disasters. If it does not get cold fast enough the grapes may begin to rot, fall off or be eaten by pests. If it gets too cold too fast the grapes are frozen solid and cannot be pressed. But if the conditions all align it produces a sweet wine that retains a refreshing acidity as well. Riesling is probably the most common grape used for Ice Wine, but in Canada the hybrid grape Vidal is often used as well. However, everything from Cabernet Franc to Gewüztraminer has been used to make ice wine. Germany may have been the first to make ice wine and Canada may dominate the market but Austria, U.S.A., and many other European countries are also making this frozen treat that goes great with fruit based desserts.
Letting the grapes turn into raisins is another way to achieve a dessert wine. You remove the grapes and let them dry on racks, until they become raisins, very little water left makes for a sweet wine. Italy is the dominant user of this style to create their dessert wines. Tuscany uses it to make Vin Santo, Veneto to make Recioto Soave, and Recioto della Valpolicella. But the French use this method to make Vin de Paille. It is also sometimes the style of wine used as a starter that is then fortified and made into Sherry. It is great with almond based desserts.
You can also add sugar or honey to a wine in a process known as Chaptalization, it is extremely frowned upon and even illegal in the upper tiers of dessert wine classifications, but there are those that still use it all over the world. Germany has another method of adding sugar to a wine known as Süssreserve where just straight grape juice is added to the wine both to sweeten it and to dilute the alcohol after fermentation has completed. This method is again not popular among producers of quality dessert wine but provides a sweet product for a more affordable price. They are best enjoyed with sharp aged cheeses to help cut the sweetness.
Dessert wines are potent and being sweet are usually enjoyed in small quantities, which means small glass ware. You can purchase specific glassware for each specific type, but a good general rule is a small glass. The temperature to be served at is unique to each type of dessert wine, but another rough guideline to follow the lighter in colour the cooler in temperature, the darker the closer to room temperature.
The great thing about dessert wines means that their higher sugar content allows them to preserve their flavours for longer once opened. Ice wines can last 2 to 3 weeks once opened if stored in the fridge and corked. Madeira has the longest life once opened as it was made to last and already is fully oxidized. It can keep for years just watch out for evaporation. Vintage Port or Asti are the exceptions to this rule they are meant to be consumed within the first night or two after opening. However for the most part dessert wines have a opened life of a few weeks. Just remember to keep the bottle sealed, cool, and the more left in the bottle the longer it's life.
Dessert wines tend to run on the expensive side due to the difficult and expensive production methods. It is said only a single drop of juice can be squeezed out of a frozen grape for ice wine, you can only imagine how many frozen grapes it takes just to make a single bottle, even if it is a smaller sized bottle. Not to mention when you take into consideration the gamble winemakers take by leaving the grapes on the vine past the normal harvest date. The chances for losing an entire crop whether it be to weather or pests is doubled. Plus noble rot doesn't affect an entire bunch, so the pickers must make several passes through the vineyard to ensure they get only the most nobly rotted grapes. Then there is the fact that some dessert wines require years of aging before they are even released to the market, like a Sauternes with it's minimum 3 years of aging. Thus delaying the return the producer has invested in it, which also raises the price. A Dessert wine is like a Fabergé egg, difficult, rare and expensive, but they both capture incredible elegance and beauty in such small packages.