Why shouldn't I let the filter of the Berkey® Sport Bottle freeze?
To refresh the water in your bottle, you may want to put your Sport Berkey® filtering bottle in the freezer for about 20 minutes. ABSOLUTELY NOT!!!
We formally advise you against letting the filtration elements freeze. We also advise against storing the elements (even unused ones) in very cold climates. Indeed, very cold or frozen water may expand inside the filter and consequently increase the size of the pores, which would make the filtration inoperative. Whether the elements are unused or used and completely dried, a small amount of moisture may still remain inside the filter, especially in predominantly humid climates. This moisture could expand inside the element and render it unusable.
This recommendation applies to ALL of our Berkey® filter elements. Freezing your element and rendering it unusable will void your warranty coverage.