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Story and pictures by Randy Mosher
Republished from BrewingTechniques' November/December 1997 issue.


Last week Randy topok us through some initial steps in Part one of this series. If you missed it, just click here...

Some Special Touches

Once you have the skeleton of your brewery assembled you can begin thinking of ways to make it easier to operate and to enhance its appearance and utility. My brewery may not yet be anywhere near operating by telemetry, but it does have some neat features to keep me happy in the meantime.

Copper-bottomed kettles: As already mentioned, stainless steel makes terrible cooking pots. Kitchen cookware often incorporates aluminum or copper layers sandwiched together, so why not apply this material to brew kettles? I managed to latch onto some 9/100-in. copper sheeting I thought would be perfect. My plan was to saw out all but a couple inches around the rim of the keg bottom, overlap the copper about a half an inch, then weld the two together somehow.

The problem is that few methods exist for joining copper to stainless. Silver brazing is one choice (be sure to use a food-safe alloy), but requires a very tight fit, which is hard to achieve on the bottom of a curved vessel. I did one of my kettles this way, riveting the copper to the stainless every inch, but it was extremely difficult and I ended up patching the pinholes later with another method. Still, it can work. The method requires an oxyacetylene torch -- not for blazing heat, but for the massive BTUs that must be pumped into such a large hunk of copper to get it hot enough for the braze to melt.

An employee at a welding supply shop suggested I use an aluminum bronze TIG welding rod (at right) to join copper to stainless as an alternative to silver brazing. Welding aluminum requires AC current rather than DC, which results in a slightly wilder and woollier welding experience, but it gets the job done. The aluminum bronze is very thick when molten and fills gaps beautifully. The trick is to get the heat applied in such a way that it more or less welds (melts) the copper while brazing the aluminum bronze to the stainless. A fellow keg-welder reported great results using a silicon bronze TIG rod. This material can be welded with straight polarity DC current, making it more controllable.

The glorping valve: I first saw this trick on Darryl Richman's brew rig. It is a large pipe fitting at the bottom of the mash kettle through which the mash can be discharged without scooping it out by hand. I have fitted my mash kettle with a 11/2-in. Tri-Clover fitting, which can be attached to a large ball valve and a foot-long elbow of the same size pipe. This elbow leads into my lauter tun. At the end of mash-out, I simply turn on the stirring motor to fluidize the mash, open the valve, and let it glorp. It takes about 30 seconds to do the transfer. The glorping valve doesn't represent a huge benefit; it's just another thing that makes brewing easier and faster. And that giant valve looks really cool!

Lauter tun tricks: My lauter tun is of fairly conventional design; it's just a big tub with a perforated screen close to the bottom. In addition to the float switch mentioned earlier, I have installed a couple of features that improve its performance.

Vacuum gauge. This gauge measures the pressure on the bottom of the lauter screen to help me prevent mash bed compaction. The gauge is connected to a tube running below the screen through the side of the vessel. It allows me to determine the rate at which the grain bed is being sucked down so I can prevent it from draining with so much force that it solidifies the mash into vegetable concrete. I open the tap carefully when starting the runoff, and if the needle starts to swing too far I close it off a bit. After doing a few brews with this you get the hang of it and don't really need the gauge any more, though the weird oat or rye beers I like to brew can sometimes throw me a curve. It may seem like a foolish luxury (if anything that costs a dollar a pound could ever be called a luxury), but saving half an hour to an hour every time I brew makes the gauge worth its weight in, as it happens, really nice zinc.

My gauge is nothing more than a pressure gauge dismantled from a CPR dummy. I took the gauge apart and bent a part inside so it reads vacuum instead of pressure. Commercial breweries use manometers -- liquids in tubes -- to do this. If you are searching for a dial gauge for this purpose, you want one that deflects with the gentlest of breaths.

Sparge loop. My lauter tun also sports an external copper coil manifold that loops around the lower third of the tun before it is allowed to spray onto the goods. It works like this: The sparge liquid is delivered to the lauter tun through a 3/8-in. copper tube that splits into a manifold made up of four separate 5/16-in. tubes. The manifold tubes reconverge into another 3/8-in. tube and from there the whole sparge is directed up to the sparge arm. This sparge loop helps to maintain the temperature of the mash -- critical to a swift runoff. It goes without saying that this entire heating loop can be bypassed, if desired.

Hop percolator: You can assemble one of these in a variety of ways, but I opted to start with a 2-gallon Cornelius affair from a soda carbonator (see figure at right). I adapted it by adding a finely perforated stainless "bucket" from a scrap yard that fit inside with 1/2-in. space all around. I cut the lid off the Cornelius keg, sawed out the keg hatch with 1/2 in. of flange, and threw the rest of the original lid away. The hatch is a standard Cornelius hatch -- it's how I get hops in and out and clean the inside. Then I cut a circle from a fresh scrap of steel to serve as the new top, welded in the Cornelius hatch, and added a CO2 fitting (for venting) and a 11/2-in. Tri-Clover elbow to connect the keg-cum-percolator to the brew kettle. Once all that was welded and cleaned up, I welded the perforated basket to a narrow solid rim and then to the lid assembly. When I was finished attaching those parts I polished the welds thoroughly. Then, I welded a 1-in. Tri-Clover fitting very low on the side. The final task was to weld the whole lid assembly to the rest of the can, align it in such a way that the large elbow pointed away from the outflow fitting on the bottom. For obvious reasons, it was impossible to polish the lid weld like the others, so I always use great care in cleaning and sanitizing around it.

I use the hop percolator to add hop aroma by charging it with hops, or simply use it empty as a coarse filter to remove hops from the wort. I usually sanitize it by boiling a little water inside it, and then I load it with a pound of hops and attach it to the matching 11/2-in. valve at the bottom of the brew kettle. I fit an open-ended gas hose to the gas fitting and clip it so the open end is above the liquid level in the kettle. This vent tube allows air to escape from the percolator as it is filled by wort, and making its opening higher than wort liquid level ensures that none will spill out.

At the end of the boil I allow the wort to settle for a few minutes, then crack open the big valve until the percolator fills with wort. After letting the wort do a little more settling, I open the valve attached from the bottom fitting to the pump (and thence, to the wort chiller) and pump wort through the chiller to the waiting carboys.


Click her to read the final installment of this series...

RESOURCES
Back issue liquidation sale
Working with Stainless Steel
Stainless steel is hard to work with, but its rewards make it worthwhile if you're willing to use some elbow grease. You have to attack each fabrication step with the correct tools and techniques or you'll make a mess of things.

Drilling: Very sharp cobalt drill bits will do the trick if applied to the metal. Do this slowly and firmly and with a lubricant. Start with a small (1/8-1/4 in.) hole, then step up the diameter with larger and larger bits until you reach your finished size. Stainless steel gets harder as it heats up, so curb your natural inclination to speed up the drilling. I have transformed cobalt bits into red-hot nuggets of useless space-age metal by misapplying my frustration this way.

Threading holes: Tapping (threading holes) is exceedingly difficult and may not even seem worth it if you inadvertently break off a hardened steel tap in the hole; some steps can be taken, however, to improve your odds. Spiral taps, if you can find them, work much better than straight ones because they clear the chips out of the hole and prevent them from gunking up the tap. Spiral taps are strictly an industrial item, but they do occasionally show up at the junk shops. You absolutely must use a lubricant and very gentle pressure, backing the tap out of the hole frequently to clear the chips. Whatever the recommended drill hole size is for a given finished threaded hole (check your hardware store for this), you can make it a little oversized, relying on stainless steel's superior strength to keep the threads from failing. Some taps are also available in sets of three; each tap is designed to take a slightly larger cut than the preceding one until you reach the desired thread size.

Cutting: Stainless steel may be cut in a number of ways. For sheet metal, the slickest device is a plasma cutter, an electrical unit that sends a needle of 12,000°F (6,650°C) ionized gas shooting through the metal. At $1,000, plasma cutters are obviously too pricey for a buck-a-pound homebrew lark, but they often may be rented from welding supply houses. With a plasma cutter, slicing through metal is literally like cutting butter; the metal simply falls apart as you move your hand. It cuts so effortlessly that it's easy to forget that the just-cut metal is hot enough to seriously burn you if you drop your guard.

For us normal folks, simpler tools will suffice. A saber saw fitted with a bimetal blade and run at its lowest speed will do the job. (If it's not making a hell of a racket, you're doing something wrong.) Carbide grit blades are a little slower, but are more forgiving in terms of speed and technique. My low-rent tool of choice is a 1/4-in. die grinder with a 3-in. cut-off wheel. The wheel will give you a very precise cut once you get the hang of controlling it. The die grinder itself (essentially a 25,000 rpm motor with a chuck on the end) is also good for many other fabrication tasks (more on this in the main text).

An abrasive cut-off saw is the first choice for cutting rods, tubes, and other stock shapes. This tool is just a scaled up version of a die grinder, with a clamp to hold the item to be cut and a far larger motor and disk. An old circular saw can be fitted with an abrasive cut-off saw, but be sure to set up the project safely in an area that can endure a serious shower of sparks.

Rolling: Rolling and bending parts requires specialized tools and is not a realistic possibility because of their size and expense. Keep in mind that stainless steel is quite tough, and a tool designed to contort a certain thickness of mild steel will be able to handle stainless that is only two-thirds as thick. If you want your sheet metal rolled, bent, or sheared, a sheet metal shop may be willing to handle the job for a small charge.

The most common types of stainless steel you will find are 304 and 316 series. The 316 metal is a bit more corrosion-resistant, but either type will work fine in a brewery.


Randy Mosher is a beer author/lecturer and freelance graphic designer based in Chicago. A BJCP-certified national judge and a home brewer since 1984, Mosher has made presentations to a number of national and regional homebrew conferences and writes on beer and brewing topics for a variety of beer and home brewing magazines. He also serves on the board of advisors for BrewingTechniques magazine and is the author of The Brewer's Companion, an advanced homebrew reference guide published by Alephenalia Publications of Seattle.


Here are some HBA favorites:


O'Mathis' Irish Lager: Light amber colored brew with a medium body and a smooth mellow hoppiness. Though finding information on Irish lagers seems to be impossible, we've decided to give it a try and create our own version.

Oxford Nut Brown Ale:: Member of English Mild family. Deep amber color, malty, nutty flavor to go along with medium body. Good choice for those who shy away from the hoppier styles.

Bridget's Love Potion Saison: Saison beers are distinctive specialty beers from the Belgian province of Hainuat. These beers were originally brewed in the early spring for summer consumption, though contemporary Belgian saisons are brewed all year round with pale malts and well dosed with Belgian hop varieties. Lively carbonation ensues from a secondary fermentation in the bottle. The color is classically golden orange and the flavors are refreshing with citrus and fruity hop notes. (Starting Gravity: 1.066-1.070) (Finishing Gravity: 1.014-1.018) (Approximate Alcohol content: 6.5-7.2%)

Ram's Head Weizenbock:: As its style name implies, German wheat with bock strength. Quite a combo!! Deep amber color, medium to full bodied with banana and clove character apparent (except in dry yeast version).

Chappaquiddick Ale:: Chappequiddick Ale is a Boston style ale that is characterized by a malty body and medium bitterness with a very clean finish devoid of yeast characteristics. It will be medium to dark amber in color. A refreshing ale with the hues leaning towards tan. An excellent session beer! (Starting Gravity: 1.042-1.048) (Finishing Gravity: 1.007-1.013) (Approximate Alcohol Content: 4.0-4.5%) (35 IBU)

St. Nick's Holiday Ale:: St. Nick's Holiday Ale is a delightfully spiced ale with accents of cinnamon and vanilla. Mildy hopped with nice honey flavors balanced by the nutmeg and clove. This Amber colored malty ale will really warm up your winter nights. Brew early to make the Holidays! (Starting Gravity 1.070- 1.075) (Finishing Gravity 1.011 - 1.016) (Approximate Alcohol Content: 7.0-7.5%) (25 IBU)


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