Normal Yeast Activity?

Hey folks,

I've witnessed something that I've never seen before and am checking to see if normal, or if its something I should fix.

I pitched my yeast last night (Danstar Windsor Ale that I started with cooled wort four hours prior) into my wort which was at 75 degrees. The wort measured 1.065 on the hydrometer.

I keep my house at very close to 68 degrees. Within eight hours I had my first airlock bubbles. As time progressed the bubbling got bigger and badder until about 20 hours in it looked like I was literally boiling water in my airlock. 4 hours later, it slowed and stopped.

Is it normal for yeast to get going like that then just stop? I know that its probably still working inside even without the airlock not bubbling, but it was such a healthy boil it was kinda shocking to see if just die off so shortly.

Thinking that it might be a little chilly, I tried a warming pad wrapped around the fermenter in a towel and swirling the beer (to suspend the yeast (just shook the bucket) a bit but no difference. Also double checked to make sure my lid was on tightly, as tight as when we began, it was. The airlock is still on tightly as well.

Is this normal or is there something else I should do to it? I plan on letting it set for a week and a half as is before moving to secondary, but just wondering. I had planned to take a hydrometer reading but my darn thing broke. Also tried searching for this on both Google and here, but didn't find anything similar (maybe my wording could have been off).

This is exactly how mine went. It started again a week later but 3 days after the 2nd fermenting action, there is no change in the hydrometer reading. It's weird.

So it restarted itself after a week? Holy crap. I've never seen an airlock move like this. It was like water at a high boil. Could have made Ramen on it.

The hydrometer reading is the only thing that matters. If BrosBrew had airlock bubbles after a week of inactivity, but the hydro didn't change, then no fermentation took place.

airlocks bubble, or don't bubble, for a variety of reasons. It could be fermentation, or not.

trust thy hydrometer.

I had several brews with the same problem, good vigorous airlock activity for the first day(s), then they just stop working. However, I soon realized that it is because the grommet for my airlock is getting old/worn. I got myself a new grommet and it seems to be okay again.