A new law, aimed at avoiding a repeat of what one German newspaper called the ice wine fiasco of 2011, has been enacted in the German state of Rhineland-Palatinate, home to leading wine regions such as Mosel, Nahe and Pfalz. It requires wine growers to declare before the harvest what grapes they intend to use for ice wine.

True eiswein, or ice wine, is only possible in the world’s northernmost vineyards, where a suitable frost can reasonably be expected. It’s an expensive and risky venture. Under German law the grapes must freeze on the vine. Artificial freezing, such as is practiced in New Zealand, is strictly verboten. The grapes must be harvested when the temperature is –7° C (19° F) or colder, and a big labor force must be available on short notice for the early morning hours of the first day they freeze. All of the grapes must be harvested before they thaw—thawed grapes rot quickly—and must be pressed while frozen.

Only the water in the grape freezes. Sugars and other components don’t, and the result is a much smaller yield of concentrated, very sweet elixir. A grower can produce, on average, 100 to 200 liters of ice wine for each acre of vineyard, compared to more than 4,000 liters for other wines.

Until now, growers only had to file a quantity report by Jan. 15 of each year. The wine inspectors of the State Appraisal Office (LUA) had no information regarding the acreage growers planned to use for ice wine, the type of grape or the quantity anticipated. Now growers must report all of that information by Nov. 15. State Environmental Minister Ulrike Höfken said the new law will help preserve the reputation of the state’s ice wine by enabling the inspectors to “keep an eye” on the suitability of the grapes. They are expected to pay particular attention to growers who have presented problems in the past. A grower who fails to make the report will be subject to a fine.

The new law was triggered by very poor ice wine conditions in the winter of 2011-12. “Our fears were unfortunately realized,” said Höfken. “It wasn’t cold enough for ice wine in most growing areas at the time of the harvest. And the grapes were, furthermore, mostly spoiled.” Despite that, 470,000 liters of ice wine were declared. “A large part didn’t meet the legal [rules] for ice wine and couldn’t be marketed as such,” said the minister. More than 90 percent was rejected by state inspectors, a heavy blow to winegrowers. Several of them took legal action. Administrative courts in Mainz, Neustadt and Koblenz all rejected their claims, and now one grower, Weingut Anselmann of Edesheim, has appealed to a higher court in Koblenz. It has yet to hand down a verdict.