I make soft pretzels for football games I host at the house. Would the dough rise if I used a yeast starter from an old beer, I would not buy a fresh yeast as they cost more than bread yeast but If I have some yeast it would be cool to use it.
It would work. It is probably not the ideal yeast to use, although you just may need to allow for a little more rise time (an observation based on my experience making various breads with beer yeast).
Also wouldn’t hurt if you fed it up a bit so the yeast is is really active and raring to go when you make the dough.
Go to the bottom of the general forum page and look for the forum Cooking/Baking/Gardening.viewforum.php?f=32
Do a search for pretzels. There have been tons of discussions about your question.