Unpopular opinion: The spontaneous kefir grain exchange I stumbled into at a Budapest hostel kitchen was the best travel souvenir. | Fermentation Station - Opinions Matter
Opening that lid must have felt like disarming a tiny dairy bomb in your sleeper cabin. Honestly, kefir that aggressive isn't a cultured drink, it's a science experiment declaring independence. Tbh you're lucky it just leaked and didn't fully erupt, redecorating your compartment in probiotic splatter. Next time maybe warn the conductor you're transporting a live, fermented culture with commitment issues. That stuff clearly wanted to see the Austrian countryside more than you did.