Yesterday I brewed up a Northern English Brown and everything went very smoothly. Hit my mash temps on the nose, had great efficiency (for me) at 76%, and everything smelled great and looked good. Then it came to cooling...
After the boil I took the kettle down and turned on the hose for my immersion chiller and about a minute later I realized I had a leak where the vinyl tubing connected to the copper and the hose water was slowing draining into the wort. I quickly pulled it out, but I guesstimate somewhere between 2-4 oz's of water got in. The good news is that it is culinary water, but the bad news is I have no idea what may be growing on the inside of the hose. I ended up starting the bathwater and using my freezer ice to get it cooling, while I ran to 7-11 and picked up an ice block and another 20 lb's of ice. I was still able to get it down to 65 degrees in about 50 minutes, which is only about 15 minutes slower than my chiller, so no real harm done there. I just worry about possibly getting an infection, though I hope the fact that it was dripping into 200 degree wort will help a bit. If I would have been thinking better I would have just thrown it back on the kettle for 5 minutes to kill anything. Only downside I can see to that would be a slight change in my hop profile, but better than a ruinded batch. I guess I will know in a few weeks.
Just goes to show you need to plan for everything because nothing ever goes 100% smooth.