Culture the yeast from the bottle. It's a unique strain. Cultures very easily. Try and get as fresh bottles as possible. They put the dates on their boxes.
I've done it and tried several times to get something similar to kepperweis, but failed every time. Really disapointed with the yeast. I understand they use large shallow open fermenters which helps create some of the flavors from the yeast. I get close, but it's sort of boring.
I've given up with it. Good luck on your attempts.