Have made x3 flavoured gins (blackberry, damson and rhubarb). Blackberry one is ready to be sieved and stored - no issues with this one. Checked the damson and rhubarb jars to find a crystallised sticky residue coming from under the rubber ring (pic attached).
This definitely wasn't there when I assembled the mixture and it wasn't there when I shook the jars daily for one week (I read too much on botulism and general food storage, so was checking the jars for leakage like a mad woman).
Any advice as to whether these are spoiled? This has happened as they've been standing upright stored in a cool dark wooden cabinet.
The liquid inside appears unspoiled as far as I can tell.
Jars were brand new and clean before use.
Gin was bog standard cheap gin.
ETA: there's no new leakage now at all when I've turned the jars to check.