If I wash and have a bagel and coffee for breakfast, then I want to continue drinking the coffee even after I finish the bagel, should I bentch and make a new bracha? Would that be a bracha she’eino tzricha?
Interesting question, because now you have two conflicting issues. In consultation with R’ Stitzberg shlit”a, author of Sharei Habracha, he said that in this case is to bentch, and he should not drink the coffee for the next little while. This way he was also mafsik from the drinking, and later on he will make another bracha on the new coffee that he will drink. He uses this idea for a different instance, see Sharei Habracha Chap. 14 ftnt 58.