wildbrine products continue to ferment in their jars and can release extra gas, causing pressure that can sometimes make it difficult to unscrew the lid.  If that happens, try the following: Let your kraut hang out on the counter for five minutes—the change in temperature relieves some of the pressure! Try running the lid edge of the wildbrine container (where the lid meets the threads of the jar) under some warm water. Then try again to unscrew the lid