Sunday, July 28, 2013

Easy Cornelius Keg Modification For Clearer Pours

The beloved 'Corny' keg has to be the brewer's best friend, time saver, ideal beer storage and serving device ever made! Originally manufactured for the Pepsi-Cola Company by the IMI Cornelius Company for distributing soda syrup to the beverage industry it is coveted by homebrewers everywhere. These lightweight stainless steel kegs are very easy to clean, sanitize and use for serving perfectly carbonated draft beer.

Ball Lock Cornelius Keg Or Corny Keg For Short

This Pepsi-Cola inspired design has two connectors located at the top of the keg, one for gas in and the other for liquid out and are commonly referred to as Ball Locks. Another nice feature of a ball lock keg is the pressure relief valve conveniently mounted on the oval keg lid. The keg lid design is large enough to allow for easy cleaning and inspection of the inside of the keg too.

Some corny kegs were made by Firestone for the Coca-Cola Company and are commonly referred to as Pin Locks. The two soda giants wanted to make sure that their syrups couldn't be easily switched to their rival's product without changing a lot of other equipment too. That's why pin lock kegs and parts are not compatible with ball lock kegs and parts. Although some pin lock kegs can be converted to ball locks, depending on the type of keg and the threads used to install the locks, only Cornelius keg parts are interchangeable with Cornelius kegs.

Beer Taps Will Connect To Corny Kegs Using Pin Or Ball Locks
Before transferring my beer to the corny keg I first let the fermentor sit undisturbed in a refrigerator for a week to let the yeast and trub fall out of solution. It's basically the same principal used when decanting a yeast starter, the cold temperature helps the yeast settle to the bottom of the flask leaving the wort above it very clear. After a week I keg the beer cold into a corny keg, put the keg back in the refrigerator and connect the Co2 line to force carbonate the beer inside.

Since I don't filter the beer before kegging it a certain amount of trub still builds up on the bottom of the keg as the beer sits inside waiting to be served and as the keg empties the pours become clearer. The very first pour from the keg seems to contain the most trub and the pours become clearer with each pour until the keg is kicked. To reduce the amount of trub in each pour I decided to shorten the length of the corny keg dip tube by half an inch, keeping the end of the tube that much further away from the sediment at the bottom of the keg.

Remove The Dip Tube Using An Adjustable Wrench
The dip tube on my corny kegs are made of stainless steel and are easily removed using an adjustable wrench, turning the ball lock posts in a counter clockwise direction. This is really easy to do even by the least mechanically inclined. The idea at this point is to simply unscrew the ball lock connector from the threaded keg post marked 'Out' on the top of the keg and remove it and the dip tube.

The Dip Tube Is Located Underneath The Ball Lock
Once unthreaded from the keg the ball lock connector will lift right off exposing the dip tube assembly underneath it. The dip tube is seated on top of the threaded keg post and is very easy to remove with your fingers.

Lift Dip Tube Out Of The Keg Post
The dip tube has a slight bend in it, just enough so that when tightened the tube end will be centered inside the keg. Most corny kegs have an inch and a half wide dimple that's about half an inch deep centered at the bottom to act as a reservoir for trub. Shortening the dip tube will increase the volume of this reservoir allowing it to hold more trub, providing clearer beer to reach your tap handles.

Use A Small Tubing Cutter To Shorten The Dip Tube
Once the dip tube has been removed use a ruler and a pencil to mark the dip tube where you want to cut it. I chose to mark the dip tube half an inch from the end although you may want to mark yours a bit longer or shorter depending on how much trub your beer contains. Adjust the tubing cutter to loosely fit the dip tube by turning the small wheel at the top, then slide the cutter until the small blade at the other end aligns with your pencil mark. The tubing is cut by tightening the small wheel and rotating the cutter around the tubing, keep repeating this until the tubing is cut and you're done.

The Cleanly Cut Dip Tube
I bought my tubing cutter a while back to use when I built my first wort immersion chiller and it's still like brand new. As long as the cutting wheel is sharp and doesn't have any chips in it the dip tube will cut extremely clean with no burrs or sharp edges that would require a light sanding. Now that the dip tube has been shortened and checked for imperfections all that's left is to give it a good rinse under running water and reinstall it on the keg.

Tighten The Ball Lock Keeping Dip Tube Centered
This is the fun part. Slide the newly cut dip tube into the hole of the 'Out' post and swing it until it's centered in the keg directly over the reservoir dimple at the bottom. Rinse off with water then hand tighten the ball lock connector on top of the dip tube, at this point the ball lock connector will still need about a quarter turn with the adjustable wrench before it's fully secured to prevent leaking. From this point on it's just trial and error getting the end of the dip tube centered directly over the reservoir as you tighten the connector using the wrench. It took me no lees than three tries until I was able to move the end of the dip tube off center enough until when fully tightened it ended up directly on center of the keg.

Flush The Dip Tube With Water Before Using
Another nice feature of the ball lock connector is that the gas 'In' connector can also be used to fit the liquid 'Out' connector for cleaning. Although the connectors are not designed to be interchangeable and the gas connector won't snap onto the liquid post you can still flush the dip tube with running water using the same gas connector.

Shortened Dip Tube 420 Special Wheat First Pour

Since shortening the dip tubes on all of my corny kegs I have been pouring noticeably clearer and cleaner tasting drafts. I forced carbonated my latest batch of wheat beer five days ago and have been sampling a pint or two each day for a few days now. Even for a wheat beer which by it's very nature is protein rich and cloudy under the best of circumstances these drafts have a cleaner taste and a rich aroma with not a hint of yeast. The 420 Special Wheat is an American Wheat beer style that combines both a huge IPA like hop aroma with a Witbier like citrusy yet not too spicy flavor that makes for a really refreshing beer.

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