According to the EU-codex wines are called Sweet Wine if the content of residual sugar is more than 40 grams per liter. The requirement for obtaining these wines is a high weight of must, which can be achieved in different ways. The must weight specifies the mass density of must from grapes, thus the mass of the most in relation to its volume.

In Austria Sweet Wines start with the rating Beerenauslese, however depending on the grade of conversion of grape sugar into alcohol. The qualification for Sweet Wine from must of Beerenauslese are therefore higher degrees of sweetness than the minimum as well as a blocking of alcoholic fermentation, in order to obtain more than 40 grams of sugar in the finished wine.

 However Trockenbeerenauslese (TBA), Ruster Ausbruch (RA) and Icewines (IW) are rated in the category Sweet Wines. The TBA’s are hand-harvested from noble rot grapes; from late fall the fungus botrytis cinerea perforates the skin of the grape and enables a partial evaporation of the water parts. Hence a natural concentration of sugar is accrued. The later pressed must becomes sweeter and sweeter by time. These are the most extensive produced Sweet Wines. Even if the market prices for TBA-wine, Ruster Ausbruch and Icewine are rather high, the extremely laborious handcraft at harvest is rarely paid for.

Icewines are godsends of nature as well as a combination of pertinent sites and – again extensive manual labour. The concentration of sweetness in Icewine is generated by the freezing of water inside of healthy grapes. By legal requirements the outside temperature at harvest has to be -7° C or lower in order to avoid a melting of the ice crystals when the must is pressed. The minimum must weights of Beerenauslese are relevant also for Icewine.

 For the vintner it is an „all or nothing“ game, because the poker about Icewine always carries the risk of a total loss, especially in years with a mild late autumn. Only ten percent of the original basic volume can be converted to Icewine in the bottle. The remaining quantity of grapes is pruned selectively or falls prey to unpredictable weather conditions.