Revision as of 10:43, 14 January 2008

Overview

How to choose a keg

You will want a keg that has only minor dents and cosmetic damage on the exterior. Choosing one that will sit flat and stable on a level surface is also important.

The Ethical Dilemma of Keg Acquisition

This is one of the very few topics within the home brewing community that sets off debates in ethics. Beer kegs can be thought of in the same way as a soda bottle or can in a deposit returnable state. It's factored into the price when you buy the beer and you get the deposit back when you return it. However, market forces in many areas have kept the deposit prices very low. A steep increase in stainless steel scrap prices has subsequently made selling an empty half barrel keg to a scrapyard a profitable endeavour, netting a 300% return on the deposit in many markets. Additionally, homebrewer conversions of these vessels into keggles has created a grey market for old kegs as well.

There are a couple ways to obtain kegs for kettle use within the law.

1. Buy direct from the manufacture (Sanke for instance). Of course, the drawback is price.
2. Buy from a brewery that has decommissioned the keg for performance reasons (leaks, bad dents, etc). This is the only way you could know for sure that a used keg hasn't been stolen.
   

Other methods of obtaining kegs have been suggested which may sidestep ethical considerations (and potentially satisfy legal requirements as well).

One can go to a scrap yard that carries a large inventory of full of used Sankey kegs, with or without brewery names stamped on the sides. The scrap yard will be crushing them all no matter where they came from. You can buy them for scrap prices before or after they are crushed. Some argue that this is just loop hole that brewers like to use to justify buying potentially stolen property.

Some of the units in this supply may have been purchased full of beer and the buyer realized he could profit by selling for scrap (and he is surely in the wrong for doing this). In another cases, they may have literally been stolen for the purpose of scrap sale. Finally, there may be kegs in this supply that the distributor doesn't want back for a variety of reasons (for example, the brewery went out of business and the value of the kegs was written off already). Thus kegs found at a scrapyard may be fair game on the ethical front, it is left as an exercise for the reader to determine whether their ethical standards are met in these circumstances.

It is also important for the reader to determine what the legal implications in your area are. There may be legal complications that arise from the purchase and use of property that may be stolen. For example, the UK Keg Watch actively prosecutes people (in the UK, of course) who are found in possession or trade stolen kegs. Many scrap dealers will refuse to buy or sell any kegs as a result.

[1]kegwatch

Converting the keg

Cutting the Top

A virgin keg after grinding‎

Warning: Before compromising a keg, please make sure you release the pressure first. Lay the keg on its side and use a flat bladed screw driver to depress the ball bearing in the top of the keg valve. If you do this while the keg is upright, you will get sprayed with stale beer. Instead of holding the screwdriver, you can also drive a thin nail into the valve just to the side of the ball bearing. it just keeps the ball from making a good seal.

keggle with top cut out

Once the pressure is released, a large opening must be made in the top to use it as a boiling kettle. First decide how large to make the hole. 12" diameters are common but you could take the entire top off if you wanted to. One trick for drawing a perfect circle is to use a loop of string slung over the valve neck. The other end of the loop is fit around the tip of a sharpie marker. Pull the marker outward to make the loop taught. If the radius is too long, tie another knot in the loop. When satisfied, pull the marker around in a circle.

With the cutting line marked, several cutting tools are often used:

Grinding

A grinding tool such as a die or angle grinder fitted with an appropriate metal cutting disc makes quick work. There are specific disc that are made to cut stainless steel. Smaller diameter wheels make the 12" diameter turn quite well.

If you rest the back of the grinder against the rim of the keg this acts as a guide.

Plasma

Jig saw

Fitting a spigot and other accessories

Spigots are traditionally added to keggles or converted keg kettles due to the fact that its own weight, plus up to 10 gallons of wort, is usually too heavy to pick up and pour. There are several ways to add a bulkhead to lower sidewall but they all require first making an accurate hole. The most common method is to use a bimetal hole saw. The size of the bit depends on the type of fitting being used which are described in more detail below.

Hole Cutting

Step Drill Hole Cutter‎

Position of the hole is determined by the internal fittings. Strainer and syphon tube. It also needs to be high enough to clear the curvature of the bottom of the kettle, this is more important if fitting a nipple due to the clearance required by the compression nut on the inside. Once the position has been determined mark it with a pencil or felt marker. The centre should then be centre punched to stop the drill slipping. There's a bit of a controversy about the use of a centre punch. Some say that it 'work hardens' the material. I personally think it's about the only way to keep the bit from walking away from the marked spot. Covering the area with masking tape can be useful.
Stainless steel is a pain to drill. Get hold of some cobalt bits; expensive, but worthwhile. Ordinary HSS (High Speed Steel) bits will dull too quickly if used for stainless. Also, obtain some cutting oil; do NOT be tempted to use WD40, use very slow speed and a lot of pressure. As the hole begins to break through, lighten up on the pressure and speed up the drill. I've successfully used my Black & Decker 9.6-volt cordless drill for drilling stainless, but it's a lot easier with my mains powered variable speed drill.

Weldless

Keggle with nipple fitted‎

A weldless bulkhead is typically constructed of a short 1/2" stainless pipe nipple which penatrates the keg wall which is flanked on both sides by a silicone O-ring, stainless flat washer, and finally two couplings. The side on the exterior of the pot will use a brass locknut between the washer and coupling to squeeze the O-rings tightly. This assembly can be purchased for $15-20 USD. The outside diameter of the nipple is .84" so a 7/8" hole is appropriate. Experience shows that hole saws typically bore a slightly larger hole in stainless than it would in wood. Therefore, it might be better to size down to 3/4" and slightly open the hole with a file if needed.

Welded

keggle with welded couplings

A more secure and permanent method is to have a stainless pipe coupling or nipple welded in to the side wall so that nipples or fittings can attached. Similar to the weldless method, a hole must be bored into the keg. A 1/2" coupling has an outside diameter of 1" but again, a 7/8" bit comes very close without making it too sloppy. A reasonable price for a welder that has capability to weld stainless (likely using TIG) is about $25 USD per fitting, The offer of a couple of bottles of your finest Homebrew can help in negotiations. The price difference between weldless/welded bulkheads is pretty close considering one is materials heavy and one is labour dependent.

Soldering

Heat source for the keg

External Heater

Internal Electric heater

Syphon tube

A syphon tube is a requirement in a converted keg kettle because the bottom of the keg dips down (concave) lower than the sidewall. This means the bulkhead/ball valve must be installed a couple inches above the bottom. The dip tube connects to the inside port of the bulkhead and dips down as close to the bottom of the keg as possible to continue draining the liquid without breaking syphon.

A syphon tube with cheap hop strainer

Hop Strainer

If you drain your wort into an external chiller such as a counterflow or especially a plate chiller, your boiled hops must be kept from entering your syphon tube to prevent clogging. In general, if you use whole hops, the straining material can be courser with low surface area because they are of larger particles. When using hop pellets, they tend to break down to finer particles requiring a tighter straining material (smaller holes) with a much larger overall surface area. It is claimed by some that a mix of whole hops and pellets helps keep fine stainers from clogging. As with many brewing items, there is a wide variety of do it yourself and commercially manufactured options to choose from:

• Hop Stopper - A commercially available option that combines a syphon tube with a large dish shaped fine stainless screen. The finer mesh stops both whole and pellet hops and works best, as claimed by the manufacturer, when a combination of the two is used. Cost is approximately $60 USD.

• Bazooka Tube - A commercially available tube of stainless wiremesh screen that is closed on one end and attached to a pipe fitting on the other. The medium course mesh will likely stop all whole hops but likely lets pellet hop particles though. Does not seem to work in conjunction with a syphon tube, which would leave quite a bit of liquid in a converted keg. Cost is approximately $20 USD.

• Pan Scrubber - A homebrewer derived method of keeping coarse particles out of the syphon tube. A stainless steel pan scrubber is a mass of long shavings wadded into a ball. It is forced under the opening of the syphon tube. The main benefit of this method is low cost (approximately $3 USD). It handles whole leaf hops with ease but is no recommended for pellets and plugs.

• Drilled Copper tube - Another do-it-yourself option whereby a longer dip tube is drilled with several small holes to create a coarse strainer. The diptube itself is sometimes made of softer copper tubing which can be bent in a circle at the bottom of the keg to provide more surface area/holes. The smaller overall area of this method requires larger holes and will unlikely stop pellet hops (probably the only option using parts you already had).

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