I brewed my second batch using a home brew kit with the two 6.5 gallon buckets. I used a True Brew Irish Stout kit and everything went well. For the first two to three days it bubbled away through the airlock and then slowed to about one bubble every one to two minutes. I could not bottle it at the suggested 7 day fermentation period, but when I went back to bottle it on day 9 it's bubbling away again at a rate of about every 10 to 15 seconds. Needless to say, I did not bottle it since it seems it has started to aggressively bubble again. Is this normal and do I just let it continue until it slows again before I bottle it?