cold crash and "reverse flow" blow off tube. Help?!?

So Im pretty sure this has been covered by the "been there, done that" crowd. I searched but didnt find the info I was looking for. Id appreciate any knowledge on how to prevent the star san in the beer issue.

For those who dont know. I dropped the temp of my fermentation chamber. As the temp of the fridge dropped the blow off tube sucked up star-san and dropped about an ounce into the beer. Prob not the best thing, but prob not the worst either.

So, as of now the temp in the fridge is still slowly dropping. I go in about every 2-3 hours and break the siphon.... And cross my fingers that nothing nasty gets into the beer.

Any thoughts?

Typically when I cold crash I just cover the beer with sanitized tin foil secured with a rubberband. Your going to have "suck back" in a airlock or blowoff tube. Once the temperature stabilizes i reapply the airlock. If you keg, better yet to just cold crash in the keg and discard the 1st pint.

I put a lil vodka or rum in the airlock....if it gets in my beer it won't hurt and you'll never taste it!

foil....damn.... should have thought of that. I knew itd be easy.

Thanks bud

no problem... its the same way most people ferment and cold crash their starters as well.

Normally I use the airlock that looks like a bent worm vs the 3-piece airlock. I put water in the airlock and fill it below the max line. If it does get suction back into the carboy the siphon will break itself because there isn't enough water to make it over the hump in the airlock to get into the carboy. Once I start getting positive pressure in the carboy I change the airlock out for a blow off tube. Usually I wait a day or two to switch over. I want a good flow of co2 out of the carboy to create a gentle airflow away from the opening to blow away any bad things that could get into the beer.