Yep, totally have setbacks from time to time. My last helles I used a new stainless chiller and did not clean it as thoroughly as I thought I did. Ended up with purple boiling foam in the kettle. Seriously. The foam from the boil start was bright purple.
Needless to say that is the first batch I have dumped before kegging it in about 8 years. Oh well, learned my lesson.