I’ve not had many blow-offs before (only krausen coming out through the airlock when fermenting the Weisse Katze hefeweizen), but the Purring Nun Belgian Strong Dark Ale I brewed on Saturday is fermenting like crazy and when I came from work to have a look at it, I first noticed that the airlock was full of dried up krausen, and then I realized that the pressure inside the bucket had lifted the lid up a couple of centimeters, letting a thick and yeasty goo run down the sides of the bucket. I changed out the airlock to another sanitized one I had lying around (didn’t have any material for a blow-off tube) and cleaned up the mess. Luckily I had the fermenter wrapped in a wet towel to keep the temperatures inside somewhat intact, which meant that no krausen/beer had spilled on the floor or walls. Hopefully I didn’t lose all too much yeast and hopefully nothing unwanted (bacteria etc.) entered the bucket. Wyeast 3787 seems to be one heck of a monster. I’m trying to keep the fermentation temperatures high (around 25° C), to make sure it finishes dry and with the correct ester profile. Hopefully the low pitching temperature (around 15° C) suppressed some fusel alcohol formation. Hopefully there won’t be anymore blow-offs. I guess the lesson learned is not to put 23 litres of high gravity wort in a 30 litre bucket without a blow-off tube or use of a foam suppressant.