This DMSO is 99% pure and as a result it tends to crystallize when at a temperature under 18 degrees.
You can reliquefy it by placing it in a warm water bath. To do this, fill a container with warm water and ensure that the water covers at least half of the sealed DMSO bottle (please keep the lid on when reliquefy the DMSO). It may take 5-20 minutes for the DMSO to reliquefy. If the room is particularly cold, it could take a bit longer.
To prevent the DMSO from crystallizing again, keep it in a warm dark place with an ambient temperature of 20-25*C.
DMSO can be crystallized and remelted without damage. DMSO should only be used in its liquid form.