Stainless steel flasks are the perfect container in which to transport liquor. What many do not know, however, is that stainless steel flasks can also be used to store liquor for several days. Stainless steel flasks are only designed to store straight liquor, so mixed drinks and other drinks (especially acidic ones) should not be stored in a flask, but if it is straight liquor that needs storing, a flask can be used to do so.
Rinse the flask out with water if this is the first time you will be using the flask. Dust and debris can make their way into the flask during the production, packaging and shipping process, so it is important to rinse the flask out before using it. Do not use dish detergents, as these can stain the inside of the flask.
Pour the liquor you wish to store into the flask. If your flask came with a funnel, insert it into the flask's opening and pour the alcohol into the funnel's opening. If your flask did not come with a funnel, hold the flask over a sink and carefully pour the alcohol into it to avoid spilling. Do not fill the flask all the way up to the brim to avoid spilling and/or leaking. Screw the cap on tightly to prevent the alcohol from being exposed to the air.
Store the flask in a cool, dark place.
To maintain the flavor of the alcohol, do not store alcohol in a metal flask for more than three days. Empty the flask and rinse it with clean water after you are done storing the alcohol.
Alcohol that is stored in a flask for longer than the recommended period of time will begin to develop a "metallic" taste.