[dbeechum]

I think my best one involved firearms and beer.

I just picked up a new to me Springfield 1903A3 (what can I say.. I'm a well armed liberal who likes to shoot for the challenge of it).

Set it on my chest freezer above a couple of carboys of almost finished cream ale (I was letting them come up for a d-rest). Pulled the bolt to inspect the barrel and set it down on top of the freezer. Turned my attention back to the barrel and heard that ominous metal rolling sound. Looked down in time to see the bolt come rolling off the freezer lid and start falling right towards one of the carboys. Time did the slow down thing as I tried to reach for the bolt, but to no avail. *ping* *crack* and 5 gallons of fresh cream ale pouring out onto the dining room carpet through a carboy length crack.

Again.. firearms and beer just don't mix.

[wormser]

Once had some buddies over and brewed up a batch of a two hearted clone and then a belgian strong ale.  Had a few beers which I very rarely do during the brewday.  As I was pouring the starter into the belgian, I realized it was the starter I had made for the two hearted and the starter for the belgian was already in the bucket with the two hearted.  Felt like a complete jackass.  Beers came out tasing OK, but would've been awesome if I would have used the correct yeast!

[darkerpower]

While brewing i generally try to get other things accomplished.  Most of the time its get the next batch of beer started so I don't waste a lot of time.  I tried to bottle wine once while brewing a double batch.  I left the bottling buck spigot open from when i cleaned it.  end result was about $100 worth of pinot grigio ended up on my kitchen floor.  My house is over 100 years old and slopes very slightly.  Most of that wine ended up going into the floor vent. 

New rule after that experience: always triple check to see the spigot is closed and never siphon into the bottling bucket without being there to watch it.

[stout_fan]

I brew out on the deck. I pump the wort through 35' of line to the 27 gal ferminator in my wine cellar.
One RIS batch I forgot to remove the safety weight from the OPV valve.
The ferminaror filled about a gallon and a half.
The pressure popped the fill tube (a drilled #7 stopper in the lid) out.
The remaining 10+ gallons of 25°P RIS flowed onto the lid and then the floor of the wine cellar.
I spent the next three months unloading racks, mopping, cleaning and drying the floor, and reloading racks.

[Slowbrew]

I was not paying attention one day making 2 batches and not only pitched the wrong yeast in both beers but also used the wrong hop schedule on both.

Both beers turned out well but neither one was anything like I was expecting.

[tappedout]

I opened a keg of carbonated beer to add dry hops without bleeding off the pressure.  Beer volcano ensued.

[etbrew]

While brewing i generally try to get other things accomplished.

Last time I did that it was a mess.  I had some people over for the super bowl and had planned to brew early in the morning.  Well I never got to brewing in the morning so I ended up brewing while making food for the festivities.  I boiled over twice (once after what should have been flame out, put the lid on and forgot to turn the burner off) and then I put the wort in the fermenter, set the food out, cleaned up and then saw my starter on the counter...

[rlshep]

+1 on mixing up yeast starters. Mine was a Saison & Dark Ale.

My worst brew day started not long after I started brewing outside on the turkey fryer setup. I had turned the gas valves on wrong and tripped a safety switch that I did not know about. Two and a half hours later and still couldn't figure out why I didn't have a boil going on my RIS. To top it off when cooling later that night, my immersion chiller sprung a leak and filled up my kettle with tap water.