Most gin can be sold as soon as it comes off the still, but some producers age their gins. This is usually done in wooden barrels that previously held other spirits so that the gin takes on some of their properties. For example a gin aged in rye casks will taste spicy and would be particularly good in a Negroni, whereas a gin aged in barrels that held Islay whisky will taste smoky and would be good in a Martini.