I'm a hardcore StarSan fan. We did some tests at the shop with their marketer when I challenged her on the no-rinse bit; I just couldn't bring myself to do it! We doctored up to, if I recall, four ounces of SS (working solution) in a 12-ounce beer without noticeable flavor impact which absolutely staggered me. That is MANY orders of magnitude more than you'd ever get from just not rinsing, but still no problem. Granted, beer has some more buffering capacity than mead/cider/wine, but combined with its proven record in thousands of breweries nationwide and demonstrated lab results it sold me. I make up 5 gallons and store in a tightly-lidded bucket for several batches of everything I make as well as a spray bottle for extra touch-ups like the nozzles on quick-connects when I'm brewing on the big system outside. I even use the spray bottle for kitchen sink faucet handles, countertops, canning, easy sanitizing of dog bowls, you name it. It's not that the stuff is that expensive, but I'm thrifty so re-using the solution makes sense for me
. All products work well when used on a clean surface with sufficient contact time according to directions: hypochlorite/bleach is crazy cheap and wicked effective (though rinse rinse rinse with hot water to prevent off flavors, and remember mixing it too strong REDUCES its effectiveness), One-Step, Star-San and related products (SaniClean), etc.
That said, rinse water from a municipal source is a pretty unlikely source of contamination. It's
much more likely to be mouth germs, cigarette smoking, an errant fruit fly, or soiling on the vessel that prevents the sanitizer from being effective. Remember the rule: you can't sanitize dirt. Sanitization has TWO elements: you need a clean surface, and then sufficient contact time for a given sanitizer to do its thing. Grit, dirt, mineral deposits, scratches in plastic etc. will protect germs from the sanitizer, rendering it less effective. And of course ineffective sanitization of the must,
when combined with underpitching or undernourished yeast, can cause problems right out of the gate.
The occasional contamination is just nature's way of reminding us to keep sanitization practices going, and not a reason to freak out either. Charlie's immortal RDWHAHB is well-placed here... I've had people come in having
autoclaved their equipment, reducing all the plastic components to useless sculpture, when a quick soak in $.008 of bleach will suffice
.