Learning experiences Part 2

For those following our adventures in home brewing, you probably know that we had an issue with the fermentation of the stout we've been brewing. The specific gravity of the beer was too high, meaning there were still a bunch of sugars in the beer that the yeast weren't fermenting. The danger with this is that if we went ahead and bottled this beer, the yeast should resume fermentation of the additional sugars in the bottle, and since there would be more sugar than normal, the bottles could explode. These are called "bottle bombs" in the home brewing world, and can be extremely dangerous. I don't know about you, but I'd rather not have hundreds of glass shards flying at me when I go to get a beer out of the fridge.

Originally we had tried adding a new yeast packet and some yeast nutrient to the beer. This was the advice given to us by the owner of the home brew store, so we figured it was probably pretty sound. Well, turns out it had no effect. To be fair, we're still not sure that the issue was just that the yeast gave up, it could also have been that there wasn't enough oxygen in the beer for them to reproduce properly and get to the level where they could ferment all the sugars. I'm actually leaning towards this explanation.

Anyway, as a last ditch effort, we decided to make what's called a starter. Basically, it's a concoction you put together to get yeast going, that you then throw in the beer. We got some water boiling, added about half a cup of dry malt extract to it, boiled for a few minutes, and then got it cooled down. Basically following the same procedure as when we make beer, just with a lot less time and no hops. We then put it in a bottle and shook the crap out of it, to make sure there would be plenty of oxygen in the wort. We added a packet of yeast to that, once again using Nottingham yeast. We loosely covered it with foil to keep any nasty bacteria out, and left it overnight to start fermentation. The next day, Dan took the mixture and shook it up again to get oxygen in it once more, then dumped it in our beer.

Sure enough, not long afterwards he told me we were getting bubbles in our airlock once more. In fact it continued to increase over the next few hours, to the point where he had to take the airlock apart and put in a blow off tube instead. 48 hour later, the bubbling is still going and we've had krausen form, so we're pretty sure it's going to finish fermenting just fine. If this ever happens again, I'm sure we're going to make a starter right away instead of using it as a last resort.