i had a friend who was a very good fox trapper and also raised foxes, he collected alot of fox urine which he would sell along with his home made fox lure. When it came to fox urine that he used on his own line he would place it in plastic gallon jugs half full and freeze it multiple times and what did not freeze he poured off into his own small bottle which he used on his trapline. He also had an additional ingredient that he would ad to his fox lure for his use only.

How many of you freeze your fox urine to a concentrate to use on the trapline?

I've done It. Once you have removed some of the water from the urine It pretty much becomes a lure. And It does make a difference.

X2. Turns almost syrup consistency. Works great