What’s the diff between age and maturity in liquor?

Dear Cecil:

Please answer a question that came up over a (three-fourths empty) bourbon bottle the other night. What's the difference between "age" and "maturity" in hard liquor?

Cecil replies:

So what if this is a Playboy Advisor kind of question. This is stuff you need to know.

Freshly distilled whiskey is unfit for drinking–about as palatable as crude oil. Once it comes out of the still it goes into storage, and only properly becomes whiskey with the passing of time and completion of a series of chemical changes. Bourbon and rye, for instance, are stored in white oak containers that have been carefully charred on the inside in order to let chemicals in the wood mix with the brew, and to permit oxygen to enter through the pores of the staves. The barrels are systematically heated and cooled–this is called the “breathing process”–first forcing the liquid, under pressure, to expand into the pores of the wood, and then to draw oxygen back as the liquor is allowed to cool and condense. The faster the “breathing,” the faster the chemical changes take place. The liquor is said to be “fully matured” when the process has run its course. “Maturity,” then, is a relative measure, the degree to which the chemical changes have been completed, while “age” is a simple linear measure of the time the liquor has been in storage.

Send questions to Cecil via cecil@straightdope.com.

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