What is a spile used for in barrel storage?

A spile is used in barrel storage primarily to stop the vent of a barrel. In the context of bourbon aging, barrels can sometimes need to release pressure or allow limited airflow; the spile serves as a device that can block or seal these openings. This helps in controlling the environment inside the barrel, which is critical for the maturation process. By managing the airflow and pressure, it ensures that the bourbon can develop its flavors without losing too much to evaporation or oxidation.

The other options, while they introduce interesting concepts related to bourbon aging, do not accurately describe the function of a spile. Infusing flavors involves different methods, such as adding additional ingredients directly into the barrel rather than using a spile. Preventing evaporation is a function that can be managed by other means, including the careful selection of barrel placement and monitoring humidity, rather than a spile. Regulating temperature is also important in bourbon production but is typically managed through the storage environment itself rather than the use of a spile. Thus, the role of a spile is specifically to manage the venting of the barrel, making it essential for controlled maturation.