wetting

pissaaminen

kastelu (present participle of)
The act of making something wet.
1838, George Adolphus Wigney, An Elementary Dictionary, Or, Cyclopaediae, for the Use of Maltsters, Brewers &c. (page 28)

It is usual to expect, that the first two or three wettings or steepings of grain, at the commencement of the malting season, will not make so good malt as succeeding steepings (..)