The main precursor of urethane is urea, which is formed during alcoholic fermentation as a metabolite of arginine, one of the most abundant amino acids contained in must, and is used by yeast as a nutrient. In the yeast cell there are various enzymes that can produce various compounds from arginine, including carbamoyl-phosphate, the amino acid citruline, and urea. all these compounds contain the carbamide group. It is advisable, as far as possible, to focus on the use of yeasts that produce low levels of urea. The addition of certain amino acids (especially arginine) and ammonia salts to the musts may promote the formation of urea.

If levels of urea value are high, urease can be added to the wine. urease is an enzyme that hydrolises urea to carbonic acid and ammonia.
Determination takes place via solid phase extraction and subsequent quantification in gc-ms (gas chromatography with mass spectrometry detector).
Some states have set legal limits for the ec in response to the fao and who decision to define reference values in certain alcoholic beverages and that of the fda recommending a voluntary limit in wine. The limits (whether statutory or voluntary) are differentiated by matrix type.