In my introduction to the Basics of Dessert Wines, Ice Wines and my review on Alvear Pedro Ximénez De Anada 2003, I briefly mentioned late harvest, raisin wines, and The Noble Rot. Now it is time to delve a bit deeper into these subjects to explain why dessert wines are so sweet and luscious.

Late Harvest Wines- This is exactly what it sounds like. The grapes are left on the vines for an extended period of time. They grow sweeter and riper, first becoming swollen, and then slowly dehydrate, losing moisture and partially drying out until they start to get slightly shriveled in appearance. As this happens the sugar levels slowly increase to higher, and yet higher levels as the weeks and sometimes months go by.

Sometimes the dehydration process is helped along by workers going through the vineyards and twisting the bunches of grapes, forcing the vines to crush and squeeze shut so that very little or no moisture can get into the grapes. This causes concentrating of the sugars and complex chemical changes and compounds being developed within the grapes, which the French call passerillage.As the time goes by and late autumn becomes early winter frost and slight freezes may occur, this causes even more complex changes to occur within the shriveled and highly sweet grapes, all affecting the final maturation of the wine. Dessert wines in this style are picked when the sugar levels get to a certain point, usually set by a standards board specific for each growing region and style of wine.

In some places the grapes are left on the vine until they are frozen and progress past the point of being late harvest wines and become ice wines, although if the grapes defrost during the making of ice wine the wine has to go back to being called a late harvest wine. Also you may have other conditions affecting the late harvest grapes, such as an infection of a mold called botrytis which I will discuss later.

Raisin Wines- (also called dried grape wines) In late harvest wines I talked about how the grapes may become shriveled and starting to look sort of like raisins. Sometimes they are left on the twisted and crushed vines so long that they become almost like slightly plump and moist raisins. Or they can be harvested at the peak of their late maturity and laid out on mats in the sun to dry into a raisin like state. I slightly mentioned this when I reviewed the Alvear Pedro Ximénez De Anada 2003. Other wine makers put the grapes into special screened trays and pass forced air or mild heat over them to speed up the drying process, but quality takes time and the best are those that are dried slowly and gently. These grapes end up with such exceedingly low levels of moisture that the juice is a thick syrup that has great difficulty fermenting but produces a rich and complex wine with raisin, date, and fig like flavors.

This style of wine making goes back thousands of years and developed in the Mediterranean region in countries like Crete where it probably first evolved, as well as Greece and Italy. The raisin style of wine is thought to be one of the oldest wine styles in the world with the first written description on making these wines by Hesiod in Ancient Greece during the 8th century B.C. In his Works and Days he advised drying the harvested grapes for ten days in the sun, followed by five in the shade, before fermentation in jars. Homer prized these types of wine dearly and enjoyed the ones from the islands of Chios, Lesbos, and Thasos. The Phoenician Mago described the process in detail, covering the use of reeds and techniques in the fermentation. All of whom mentioned that these wines were at their best after many, many years of aging these robust and syrupy thick wines.

In our present times these wines are made in Spain with the Pedro Ximénez grapes, in Tuscany with Vin Santo, Veneto has the Recioto di Soave, Recioto della Valpolicella, and the dry Amarone, Vin de Paille wines from Hermitage in France, and the Commanderia wine from Cyprus, and more. Usually these raisined grapes are healthy ones that don't have any mold interfering with their growth and development.


Botrytis cinerea, The Noble Rot- There are a few different forms of the botrytis mold, some good and some bad. They are all fungal diseases of grape vines and the full name for the category is Botryotinia fuckeliana. The name alone sounds somewhat sick and mildly perverted. Botrytis cinerea is the asexual, spore-forming form of Botryotinia fuckeliana. Many different conditions cause the mold to grow in varying ways. One form is Gray Rot, also called botrytis bunch rot. This is a malevolent form of the fungus that can cause terrible damage to almost ripe or damaged grapes, usually when it is very damp and humid out.

On the other hand you have a form that is much anticipated and prepared for. Botrytis cinerea is a mold that can make something good become great. Like a benevolent monarch helping his land to change and grow, to become lush and prosperous. Botrytis cinerea does the same to grapes. There is a reason it's called The Noble Rot and it is responsible for some of the best sweet dessert wines in the world. If the grapes are ripe, healthy, whole, and light skinned varieties the same mold that could cause gray rot grows in a completely different way.

Climate, specifically meso-climate (climate that is smaller than regional in size, such as a certain river valley, but not a micro-climate as you might find in an area of only a few acres) is important to the noble rot with the best growing conditions in autumn are areas where it is misty in the mornings and warm in the afternoons. The humidity in the mornings encourages the mold to grow, and then the warm afternoon's dry off the grapes and protecting them from rotting. Areas with hills and valleys, along rivers and lakes, are very good for this, although many wine making regions are near rivers.

The three wine regions of the world where noble rot was first noticed and made into a style of wine are Tokaji in Hungary, Sauternes in Bordeaux, and the Rheingau in Germany. From those regions the style progressed to areas including Austria, Italy, Alcace, Coteaux du Layon and Vouvray in the Loire, and even in parts of Burgundy. Now noble wines are made in other parts of the world including Australia, South Africa, and California, some naturally and some artificially, by spraying the fungus spores onto the grapes and hoping it will grow. For some reason dark or red skinned grape varieties rarely get positive results from botrytis infection. The wines become gray tinged and can have an off smelling or rotten odor.

The mold affects the grapes by growing first on their skins, then slowly sending mycelia, sort of like roots, into the grape. The skin develops pores from the mold attacking it so that moisture can escape. This causes the sugar level to go up as the moisture level goes down and the grapes shrivel and become ugly with brown and spots. The mold must be left to grow fully, as it does there is a complex enzyme reaction going on in the desiccated grapes. Sugars are being made and broken down or changed into different forms like glycerol and dextrin. Flavors are deepening and maturing, and acid levels are developing. A great deal of complicated changes are happening inside these poor infected grapes, all leading to the eventual culmination in a great wine at some distant future point.

The mold doesn't usually progress at the same rate of growth throughout a vineyard. Some bunches of grapes may be fully infected and covered with mold while others are only partly affected. So instead of the vineyard being harvested all at once it may have to go through two, three or even more partial harvestings over several days or even weeks. All the grapes must be picked by hand, with each bunch being inspected individually to determine if they are ready to pluck. Sometimes each grape is examined and may be picked one by one. This is a very slow and labor intensive process; no wonder some dessert wines cost a small fortune. Once the grapes are harvested they have to be crushed and squeezed. The grapes have very low levels of thick and exceeding sweet juice which is hard to extract. The juice has such high sugar levels that it is also difficult to ferment it, so the process may be long and slow, working in bursts and then slowing down for periods of time.

All of these conditions, the sugar levels, acidity, enzyme reactions, long and slow fermentation, etc. lead to wines that in many cases can age and mature for many years, decades, and sometimes hundreds of years; with the wine changing in flavor, color, and texture throughout the whole process. Botrytized wines have certain flavor characteristics. With ice wines I discussed how the wines have fresh fruit flavors, with noble wines the flavors are deeper, rich, and complex with flavors like honey, stone fruit such as apricots, peaches, and plums, dried fruit and raisins, as well as caramel and butterscotch. Many times the wines get deeper in color as they age and it can be a good indication of flavor in a dessert wine when it has tones that are medium to deep gold, or even hints of amber to it.

A very rough indication of flavor and sweetness in most dessert wines is that if they are very light in color they will be drier and with less character; while if they are darker, they will be sweeter and more complex. Of course there are always going to be wines that don't fit into this stereotype, as you will see for yourself as you delve into the incredibly enjoyable world of sweet dessert wines.