Interesting Dry Hop Experience

So I decided to dry hop my Hazed and Infused clone the other day, with 1 oz of liberty and 1 oz of centennial. I had the beer in primary for 5 days, and then secondary for another 5 days before the dry hopping. There were a few bubble coming up through the beer, but no air lock activity while i've been watching. I threw the 2 oz into the 5 gallon secondary fermenter, and gave it a swirl to get everything wet.

Well, it wasn't long before the beer really started bubbling, and then the airlock started bubbling, about 1 bubble per second. As I didn't have much head space, I grew concerned when the foam and hop cone started creeping up and up and up. With more bubbles that didnt seem to be slowing. I said to myself, ah #&$*!, and ran out to the garage to get my blow-off tube if it came to that. I was hoping it would stop rising, but as it neared the lip of my fermenter, I decided to push some of the floating/rising hops back into the fermenter with a sterilized large spoon. That bought me some time, but in another 20-30 minutes I had to do it again. I kept a watchful eye on the whole process for about 2 hours before I was satisfied that it wasn't going to blow over. The bubbling and airlock slowed dramatically, and I finally went to bed.

Update - 30 hrs later, the hops have dropped back into the beer, danger has been everted. All is well. The beer, however, is still bubbling a little bit (more than before i added the dry hops), but no activity in the air lock over the 2 minutes I watched. This doesnt concern me, but, throught the whole process I couldn't figure out why I was getting this reaction/bubbling. It was as if I had added another pound of sugar. Is there some sort of chemical reaction with the hops that I don't know about? Anyone have any insight? Anyways, I am looking forward to the finished product, it should be a good one!

- Mark

The activity that you saw wasn't from fermentation, although you did go to secondary pretty quickly so there certainly could have been some fermentation left to take place. It was the pellets absorbing the beer and expanding.

If I'm dry hopping with pellets I'll rack to a 6.5 gallon carboy or to a bucket to avoid this. Generally I dryhop with leaf.

You simply racked before fermentation was complete.

+ 1 with what has been said already.

In addition to that, when you added the hops it provided nucleation sites for the dissolved CO2 to collect and finally escape. Try a mead some day, when it comes time to feed your yeast a couple days after the start of fermentation you'll get a huge rise of foam from the addition.

Yeah, I was rushing the whole process a bit because I needed my primary fermenter for another batch, and I want to get this batched bottled before I head out of town for a while in a week. What I really need is another carboy or 2, but that will have to wait until I have more space and quit moving around so much.

Use your hydrometer to determine when fermentation is complete and don't rack before your beer is at the same gravity reading for 2 or 3 days.