The term can mean various things in the context of the topic:
Barrels (especially wooden barrels) are made tasteless by appropriate treatment, if necessary. See impregnate and wine green, as well as a list of relevant keywords under preservation.
There is a vast number of sources on the web where one can acquire knowledge about wine. But none has the scope, timeliness and accuracy of the information in the encyclopaedia at wein.plus. I use it regularly and rely on it.
Sigi Hiss
freier Autor und Weinberater (Fine, Vinum u.a.), Bad Krozingen