Any Czech chef worth his or her paprika will tell you that the best batch of goulash is the one that sits overnight and gets mixed with a fresh batch just before being served. But, as of May 1, when the Czech Republic becomes part of the European Union -- along with seven other central and eastern European countries, as well as Cyprus and Malta -- this time-honored culinary tradition will be against EU food-safety regulations.

The rule, which states that food must be served within three hours of preparation, is one among many created by the EU in an effort to standardize commercial practices across its now 25 member states. So far, however, the regulations seem to have inspired at least as much bickering as European team building.

The tension has been around ever since the vision of a unified Europe was advanced in the middle of the 20th century. The goal of preventing the fragmented Europe of World War II and ensuring the free movement of goods, people, services, and money has also inspired impassioned (and embittered) debate about national and regional cultural preservation.

In January 2003, for instance, the Brits won a three-decade battle when the EU court decided that chocolate containing up to 5 percent vegetable fat and up to 20 percent milk must be sold, along with other varieties, in all EU countries. For countries like Spain and Italy, which had refused to sell high-fat, high-milk-content British chocolate in their shops, the ruling meant that though mainland European consumers would be free to choose among more varieties, their traditional definition of what made chocolate chocolate was diluted.