Natural Sweet Wines
They start their life as most other dry wines: grapes are picked at optimum ripeness or higher (anything from 22°Balling) before being put through the fermentation process. Fermentation must be halted part way through the process (by temperature control and filtration), leaving the wine with enough sugar to give it the required sweetness, acid to balance it and alcohol to make it "wine".
While one could use a black grape variety to make sweet, white wine, the standard procedure is to use white varieties. Favourites are the perfumed, aromatic grapes such as Weisser Riesling and Gewürztraminer. Sweet Rosés do require some pigment from red grape skins.
Here are some of the different styles of natural sweet wines:
Late harvest These are your run-of-the-mill "off-dry" wines with residual sugar of around 20 to 30 g/l (where dry is less than 4g/l, semi-dry is 4 to 12 g/l and semi-sweet is 4 to 30 g/l). The name may be misleading, because legally winemakers may (and sometimes do) add extra sweetness to the wine rather than pick the later, riper grapes. But this takes the form of adding grape juice NOT cane sugar.
Special late harvest (SLH) Grapes are picked fully ripe, although some winemakers even leave the berries on the vine until they've shrivelled up like raisins.
SLH needs an extra complexity, something "special" to elevate it above Late Harvest. Botrytis (see below) is one of the things which may contribute to the wine's complexity.
Noble late harvest (NLH) If stickies were royalty, this would be the princess bride - sweet and voluptuous with a hint of seduction and plenty of life in her. Many European nobles are known to last in the bottle up to 50 years and beyond.
NLH is separated from other sweets by one main factor - botrytis cinerea, a fungal disease which attacks and thins the grape skin, causing water within the berry to evaporate, leaving a highly concentrated sugar and acid content. NLH can only be made in vintages where the fungus attacks, which may be erratic.
Botrytis gives amazingly complex flavours: terpene, honey, apricots, peaches, honeycomb and paraffin with a slight viscosity and concentrated sweetness.
Eiswein The Germans found a novel way of getting round the infrequent occurrence of botrytis. They discovered if they left the grapes on the vine well into the beginning of the cold season, the grapes would freeze. If pressed while still frozen, iced water from the berry remains behind in the press, while the thick, concentrated sugary liquid and acid run off the press - achieving a similar character to that of botrytis.
The Canadians have also picked up on this little trick, producing some good examples.
Dried grapes Another means of gaining concentrated, sweet juices from the berry is to pick them at full ripeness before allowing them to dry out and shrivel on trays before going to press. Again, the objective is concentrated flavours and sugars, although the berries must be well aerated to prevent rot and fungus attacking them. Sweet wines in this style from northern Italy are called Recioto.
Vin de paille A speciality of Hermitage, France, is a sweet wine made from a similar fashion as the above, except the winemakers allow the berries to dehydrate on beds of straw. This is called vin de paille.
Tip of the month
The crusty residue of old ports (30 or 40 year old), once the wine has been decanted off, makes a base for a superb sauce for gamey meat dishes. There's an apocryphal tale of a widow who used to pour away the port in order to get the delicious sludge to spread on her toast in the mornings!
Compare the following styles of local port in a home tasting:
Boplaas Cape Tawny Port
KWV LBV 1997
Overgaauw Cape Vintage Reserve 1998
Die Krans Cape Ruby Port NV
