Liqueur is an alcoholic beverage that has been flavoured with fruits, herbs, nuts, spices, flowers or cream and bottled with added sugar. They are typically quite sweet and are usually not aged for long. They may have resting periods during their production to allow the flavours to "marry‟ or harmonise. The distinction between liqueurs and spirits is not simple because many spirits (e.g. vodka) are available today in flavoured forms. The most reliable guide to classification is that while liqueurs contain added sugar, spirits do not.