I've had Selcon clump up b4 a few times, think it was from "old" stock.Sometimes a bottle will clot up sooner than others, just remember to shake it up real good b4 you use it, and even on those days you don't use it, if you think of it.
On the refrig part of storing it, i think i asked that same thing a while back, can't remember what the correct answer to that was tho,,,
I think most replies were
not to store it in the frig, i seem to remember reading ,on the bottle, or in ad for it/somewhere on a site for it, that you
could store it in the frig, after it was opened/used,,,,just leave mine on the counter now, and shake the bejezzus out it, when i think of it,,,this bottle so far, has been clump-free
