Blow-Off Tubes, and why bigger is better

We had a busy weekend here at the trailer, brewing three 5 gallon batches of beer. We also experimented with propagating the yeast cultures prior to primary fermentation, with explosive results. But we’ll get to that shortly. For this weekends brew cycle we did an Altbier, a Double IPA, and a Hoppy Ale (not sure how much difference we’ll notice between the last two, but it’ll be fun trying to find one!). The yeast starters were used on the Double IPA and the Altbier. We determined that because of some slow fermentation starts previously with high-gravity beers, and older yeast cultures, that it would be a good idea to try and get a good jump start on the process.

We went with two yeast starter kits from Austin Homebrew. These are your basic 1000ml erlenmeyer flasks with a #10 stopper and three piece airlock along with 1/2 cup of pale DME. Boil the DME in 550ml of water, add to the erlenmeyer flask, cool to 70 degrees and add your yeast. Pretty basic stuff really. The Altbier used Wyeast German Ale yeast (#1007 ) which was still within the use by date, but having an original packaging date of November really gave us a bit of concern. The yeast starter was really looking like a good idea after it took a full 24 hours for the smack pack to fully expand to size. We also did a yeast starter on the Double-IPA which uses Wyeast American Ale yeast (#1056 ). This was unnecessary, and we knew going in that it probably wasn’t required. With a “born on” date of 12/6/04 it was still reasonably fresh, and previous experience told us that this yeast strain likes to get to town and start chewing sugars up fast.

Both yeast starters really seemed to take off, the American Ale much more so than the German Ale (which only served to confirm our suscpicions that this was a good idea). We went ahead and brewed all three beers Saturday afternoon/evening, and pitched the yeast starters at that time. Given the fast nature of the American Ale, we decided to add a blow-off tube to the Double-IPA (along with a bet on the need for it, oh well I didn’t mind buying a thief anyways). The blow-0ff tube was pretty active all day Sunday as we watched Kaeding miss a field goal to win the game, and Manning destroy the Bronco’s secondary. It sounded a lot like a coffee pot after the water has all bent spent, making that steam gurgling noise. Suffice to say it was a good idea. And, the yeast starters really helped as well. The Altbier really took off, which was a much better start than the last high gravity beer we brewed, it now has a nice krausen and the airlock is chugging away pumping the wonderous essences into the trailer.

The Double-IPA on the other hand might have gone a bit too fast. I woke up this morning to let the dog outside, and glanced at the carboy (6 gallon) and noticed that the blow-off tube and stopper were missing in action. I looked around the area and didn’t see it, so went ahead and took the dog outside. When we came back in, I started looking for it in earnest. I grabbed the flashlight and was looking everywhere behind, around, and under and just couldn’t find it. I started to widen my scope, looking under the fish tank, in the kitchen, and eventually found it. 6 feet away, behind the chair!! It had blown the stopper, hose, and funnel attached to the hose completly off the carboy, and six feet away! Talk about an active fermentation! Upon inspection, some spent grains had gotten clogged in the tube where the roomate had attached a funnel (I’m still unclear on the point of that). It appears the grains got wedged into the tube at the point where the funnely came in, and eventually sealed the tube completly causing the explosive properties.

Ah well, lesson learned. LARGER I.D. BLOW-OFF TUBES!! We’ll let you know how this brew turn’s out, I’m fairly confident that the thick krausen should keep us in the clear, and we won’t have to worry about any nasties starting their own fermentation. I’ll also update on the status of the AltBier later in the week.