Carboy Brewing - Burp Tube & Milk Jug Air Lock

[baumgrenze]

In the 1980's I took Prof Michael Lewis' two weekends home brewing class at Davis.

Michael taught us many tricks. I don't have the bandwidth to try and trick Google into finding if home brewers are still using them.

I want to know if the approach to brewing I describe below is well documented and known to 2018 home brewers. If it is, I'd appreciate a reply containing a link to the description.

I brewed in 6.5 gallon carboys. One key step was growing an active yeast culture from an agar slant, starting with a sterile solution of malt in water in a test tube and when it was active transferring it in steps to increasingly larger Erlenmeyer flasks until about 2 liters of starter was actively growing distributed between two 1 liter Erlenmeyer flasks. On that day I prepared an ale wort, chilled it, and then pitched it with the active starter. This ensured a quick start to the fermentation, one that was otherwise aseptic assuming the brewer followed Michael's instructions to rinse and drain all the apparatus with 1 Tbs of old 5% laundry bleach/gallon water. Within a day the brew was fermenting vigorously; it often foamed up and out of the neck of the carboy, in the process blowing out the classical stopper with air-lock.

The solution to this problem was a length of Tygon tubing of slightly larger diameter than the neck of the carboy. Each end was heated gently until it could be stretched and necked down at each end to a diameter that fit snugly into the carboy at one end and a plastic gallon milk jug containing half an inch of dilute bleach with an added hole carrying an air-lock protected with a bit of dilute bleach. This allowed a small amount of the brew to 'burp' gracefully into the milk jug and protected the wort from contamination.

I will add an observation of my own. Perhaps others now use it regularly. I bought a tube of test strips made to check for glucose in urine. After the brew appeared quiet and finished I would withdraw a few drops with a sterile rod and check for residual glucose. I liked this approach because it is less likely to cause contamination than the classical hydrometer method and it is also simpler.

thanks
baumgrenze

 

[TechFanMD]

There are a million ways to make a blow-off tube but the basic principle is the same as you describe. Not every beer needs one - you know from experience generally what will and what will not. I think most people use 1 or 3 piece airlocks for most beers.

Homebrewing has come a LONG way since the 80s. Now the yeasts and modified grains available, as well as an increase in experience using them, have made a lot of the 80's era homebrewing advice obsolete. I would not buy a used 80s homebrewing book and use it as my brew bible and follow it blindly.....I wouldn't even buy a 90s era book for this purpose.

People still make starters, and it is good practice, but probably not as difficult as it was in the 80s as there are many more yeast strains sold in large cell counts available now.

As for the glucose test strips, I have not heard of doing this, and I read a lot. The hydrometer sample lets you know your starting gravity so that you can calculate efficiency, and also allows you to calculate alcohol by calculation when testing your final gravity. Taking two or more hydrometer samples at the end also shows that fermentation has stopped. I'm not sure why taking a hydrometer sample risks contamination when executed with good brewing sanitation practices.

There is also a lot more equipment available now specifically designed for the homebrewer, and at prices that have overtaken the old makeshift brewing practices (of doing with what you could get).

 

[JohnSand]

Welcome Baumgrenze, and thanks for the flashback.
Many fermenters now have more headspace to accommodate the krausen.

 

[baumgrenze]

Thank you TechFan and John Sand.

Thanks to your replies I'm calling this the Michael Lewis Krausen Catcher.

Just to be certain that I communicated, here's a picture worth 1000 words. All I had available was an old bleach jug into which I bored a hole so I could mount a standard 3-piece airlock.

The bridging tube is ~ 36 inches of 1.25" OD Tygon B-44-3. I heated a longer piece near each end with a hot air gun and then pulled gently to neck the OD down to slightly less than 1" so that it would fit into the neck of the carboy and jug. With a good active fermentation start I estimate I might have lost 1/4 cup of the wort, a small loss for the reassurance that the fermentation was off to a good start. My notes suggest that in 36 hours a typical brew reached full Krausen.

Now that I am well into my 79th year I'm no longer up to carrying around a full 6.5 gal carboy. so my brewing days are in the past. I'm the son of a retail baker, so when I brewed I was also baking all my own bread. When I racked my beer I carefully saved the spent yeast at about 6 oz per 12 oz bottle. In my brews it always contained a lot of hop resins. I added it to my bread dough, not as the rising yeast but as a flavoring agent. A couple of slices of that bread with butter and a glass of water was 'as good as could be gotten' when I took my brown-bag lunch to work. These days I open a nice piney (no grapefruit thank you) IPA and eat artisanal bread. I've come to prefer retirement.

Thanks for hearing my story.

baumgrenze

 

[JohnSand]

Thanks for sharing the story.
I'm only 56, but sympathize about dealing with the weights. I brewed yesterday on the patio, but ferment in the basement. Sometimes I consider going back to smaller batches.