KETTLE MASHING

By Jack Schmidling


Mashing and sparging in plastic buckets of one form or another has become so universal that the method I am going to discuss might seem like something new. However, it is more or less the way beer had been made since time immemorial. Until that is, a certain very popular book on home brewing appeared.

Kettle mashing, as I call it, has some advantages and some disadvantages over the now "traditional" plastic bucket method and until one understands both approaches, a commitment to one or the other can lead to a good deal of unnecessary frustration.

Kettle mashing is simply using a kettle with an appropriate secreening device and spigot to "cook" the mash in and once the mashing is complete, the same kettle becomes the lauter tun. After sparging in the lauter tun, the kettle is used for boiling and if it has a close fitting cover, can be used as the primary fermenter.

The most fundamental advantage of the approach is the ease with which the transition from extract to all grain can be made. The only new requirement is a straining device in the kettle already used for boiling extract beer. The investment required to "give it a try", is quite minimal and if you decide you don't like the program, you end up with a great brew kettle that sports a spigot that won't get clogged up with hops and specialty grains.

The other advantages are a bit more technical and I will point them out when we get to them.

The key to the system is the screening device and the spigot for the kettle. The first one I made was to be used in conjunction with an overlaying false bottom. The false bottom was a stainless steel plate the size of the kettle bottom with a zillion holes laboriously punched into it. It created no end of problems on the very first batch. Mash got under it and scorching was just about impossible to control. So in disgust, I pulled it out, continued the mash and assumed a disaster was at hand.

Much to my incredulous delight, when I opened the spigot, the wort ran clear after less than a cup of turbid runnoff. I have since made about 30 batches using only the screen device and get very consistent and respectable extract yields.

We will begin the discussion, by describing the screening device and spigot that is installed in the brew kettle. The first one I made was made from galvanized pipe fittings and window screen, installed in a 32 qt enameled canning kettle.

The current version is all brass, copper and stainless installed on two stainless kettles, a ten gallon for mashing and fermenting and a sixteen gallon for boiling. Having two kettles allows one to be prepared for the next operation while the other is doing its thing.

Fig. 1 shows an exploded view of the spigot and strainer. The strainer is simply a 2 x 6 inch piece of screen, rolled into a six inch tube and clamped to the copper tube. The last half inch is bent over itself to seal it off. The copper tube has a slight bend in it to allow it to be rotated so that the end is right on the bottom leaving almost no wort behind. It is easily removed for cleaning.

The spigot passes through a clearance hole drilled in the kettle and is retained by the female connector and a washer to take up the treads and make a tight fit.

All the parts are available at a good hardware store. For those not inclined to hunt down the parts, a complete kit is available from the author.

Once the spigot/strainer device is installed in the brew kettle, you are ready for the plunge. If you are shopping for a kettle, my only advice is the bigger the better. I consider the 32 qt canner about the minimum for a 5 gal batch.

The following procedure is intended only as a starting point that I know works well enough to assure a successful, first, all-grain experience. I do not want to get into endless discussions about the pros and cons of the procedure at this time nor do I even claim that I brew beer this way. There are an infinite number of variations that could be fodder for future articles but the object of this one is to introduce the approach and brew a simple batch of all grain beer.

MASHING

The first step is to dump 8 lbs of crushed pale malt into the kettle. Don't forget the screen! Add 3 gallons of warm tap water and mix thoroughly.

Apply heat and raise temp to 155F. Stir frequently to avoid caramelizing and to distribute the heat. Hold this temp for 30 minutes by adding heat and stirring as necessary.

After 30 mins at 155F, crank up the heat and continue stirring until 178F is reached. This step is known as "mashout" and is difficult or impossible to do with the plastic bucket approach. It is my opinion that it eliminates one source of a common problem with first all grain batches known as a "set mash.

Hold this temp for 10 minsutes, then turn off the heat and let it rest while heating water to a boil on another burner. Use a pan that holds at least two quarts of water.

SPARGING

The level of wort in the kettle should be about an inch above the grain when it settles. Lay a small bowl on top of the grain to distribute the sparging water and minimize the disturbance of the grain.

Open the spigot just a trickle and run the wort into a cup until it runs clear. Pour the turbid runoff back into the kettle. With this setup, it will run clear after a few ounces. Again, as comparison, it sometimes takes gallons with the other system and this must be recycled back into the mash till it does run clear.

The object of sparging is to extract as much sugar from the grain as possible. The longer it takes, the more efficient the extraction. Adjust the outflow so that it takes at lest 10 mins to fill a gallon jug. Pour the boiling water into the bowl as available or necessary to keep about an inch of water over the grain. The availability of boiling water will probably be the limiting factor on sparge rate.

Most brewers will tell you that the sparge water should not exceed 170F but if you use boiling water in this system, the average temp will be far below 170F and you will be lucky to keep it above 150F. You can fiddle on your next batch. Trust my on the first.

The first runoff should be about 1.080 and you quit when it gets below 1.010. The total blend will produce 6 to 7 gallons at about 1.035 which, after boiling will yield 5 to 6 gals at 1.040. Collect the wort in gallon jugs or five gallon plastic buckets (can't get away from them).

BOILING THE WORT

When the wort is collected, dump the spent grain on the compost pile and rinse out the kettle. I always save a few pounds in freezer containers for beer bread. The seven gallons of wort will barely fit into the kettle for the boil so it is best to bring a smaller portion to a boil initially to avoid boilover. After evaporating some and getting the boil under contro, the rest can be added. A minimal one hour boil will evaporate about a gallon so you can play with the volumes in various ways. You can increase the gravity by more boiling or boil less and have more beer.

Add half of your hops as soon as boiling begins. Save one forth for the end and the remainder at regular intervals during the boil. If you need a suggestion, try 1.5 oz of Chinook for your first batch.

CHILLING AND FERMENTING

After the boil, the wort is cooled, either overnight or with a wort chiller if you have one. I draw it off, after chilling, a gallon at a time so that I can shake it vigorously and "glug" it into the primary to oxygenate it prior to pitching yeast.

If you hold the chilled wort in a carboy or gallon jugs, you can clean out the kettle and use it again as the primary fermenter if the lid fits well. Just boil a cup of water in it with the lid on for about 5 minutes to sterilize it.

The kettle seems to be universally available for about $35 and the rest of the stuff can be had for under $20, making it a pretty inexpensive system.

So, that's what kettle mashing is all about. Try it, you may like it.

Addenda.............

Here is the list of parts required:

1. Brass "air cock", 1/8" male pipe thread at one end, bibb spout at the other and lever on top.

2. Brass "female connector", 1/8" female pipe thread at one end, 3/8" copper tubing compression fitting at other end.

3. 6" length of 3/8" copper tubing flared at one end and bent so the end rests on bottom.

4. 4 X 6 inch screen (window, brass, copper or ss) rolled into tube and clamped to flared end of copper tube. (flare prevents it from falling off at inconvenient times)

All it takes is a 3/8" hole in your kettle, near the bottom. If you run a 1/8" pipe tap into the hole, you can screw on the air cock and it will not leak. However, as most kettles are too thin to provide enough threads for a safe and permanent fit, I modify the fittings by rethreading the aircock and connector with STRAIGHT pipe threads. This allows the connector to be screwed on to the aircock in such a way that you achieve a snug fit by compression instead of relying on the tapered pipe threads.

Aside from the brass screen, you can find this stuff at a good hardware store. I used window screen for months and see nothing wrong with it.

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