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Manuscript for AHA 93 conference


Bob Jones

Automatic Sparge Device -

One of challenges in all grain brewing is balancing the sparge water levels during sparging. It is desirable to keep about 1 to 2 inches of water depth over the grain bed at all times. If the water level falls below the grain bed, grain bed compaction and the much feared "set mash" can occur. If the water level rises too high then the grain bed can also become compacted due to hydrostatic water pressure. This also results in slow sparging and a compressed grain bed. Achieving this balance in water levels requires constant monitoring and flow adjustments of either or both the sparge input water and mash tun outflow. It is also desirable to minimize the heat losses due to convection off of the top of the mash. This is best accomplished by covering the mash tun during the sparge. I have developed a device that provides for automatic sparge level adjustment. This device is made up of easy to obtain parts. The heart of the device is the Float Valve(fig. 1). This device is placed at the desired mash liquid level depth and the mash water level is regulated by the float. The entire assembly can easily be adjusted to different grain bed depths by raising or lowering the whole assembly. The advantages of the device are that the mash tun can be covered to minimize the heat losses and I can go off and do other things. The water level is always at the proper level. Also, since the sparge water is being placed right on top of the grain bed, instead of dropping through the air, sparge water heat losses are minimized as well. I obtained my float valve from Graingers, it cost about $10. The output of the float valve is connected to a copper ring with lots of tiny holes in it. The holes are on the inside and outside of the ring, and are placed to evenly distribute the sparge water over the mash bed.

Pumps in Brewing -

When I set out to design and build my home brewery I had been brewing for about 8 years. I knew well the mess that can be generated in the kitchen home brewery. One of the highest priorities was to move my brewing totally to the garage. The idea for a small garage based brewery was a new concept at the time. I had seen a simple brewery using one 15 gal. keg at a friends house and decided to expand on the idea and go for as much compactness and automation as possible. I decided to construct my brewery out of three 15 gal. kegs. One for the hot liquor tank, one for the mash tun and one for the kettle. My complete brewery system is two 15 gal. kegs wide by one keg deep by two kegs high. I also wanted to have a traditional gravity flow system(fig. 2), much like the big breweries have. Rather than have three kegs stacked 10 to 12 feet in the air, I decided to break the traditional four level brewery into two pieces by using a pump(fig. 3). The pump I use is a magnetic drive pump(fig. 4). This type pump is well suited for moving liquid, because the pumps impeller is magnetically coupled to the motor via a magnet, therefore there is no chance of liquid getting into the pump, and also no grease can get in your beer. These pumps can be obtained at large industrial supply houses for about $100. I obtained mine from Graingers, I use a pump made by Little Giant. Be sure the pump impeller housing is suitable for the temperature range of the liquid you will be passing through it. I use this pump to raise the outflow from the mash tun (at floor level) to the kettle (at eye level). I personally consider this pump to be more than just a convenience, I consider it a safety device. The risk of back injury and burns is eliminated by not lifting by hand the hot wort to the kettle. An additional feature of using a pump is to minimize Hot Side Aeration(see article by G. Fix). The pump outflow can be coupled to a down tube that is placed in the kettle, that directs the hot wort below the wort liquid level, thereby minimizing HSA. It is always desirable to be able to adjust the flow rate of the pump. It has been my experience that controlling the speed of the pumps motor is not the best way to achieve this control. The best way to control flow rate is to place an adjustable valve at the output side of the pump. Even if you already have a valve on the output of your mash tun, you should place an additional valve on the output side of the pump. Just open the mash tun valve all the way and control the flow with the other valve. Pumps don't like their inputs restricted. When using the pump you should insure the impeller housing has all the air purged. This can usually be accomplished by listening to the pump. It will be much quieter then fully primed. Additionally I have never had a set mash since I started using a pump. The pump has a very high suction rate and can overcome almost any mash bed compaction problems. The sparge could easily be accomplished in 10 minutes, but I usually push it out to about 30 minutes by slowing the flow rate. Using a pump in a home brewery allows for many more options in both configuration and operation, plus the added benefit of increasing safety in the brewery. Don't forget to install a GFI(ground fault interrupter) on any power outlets near your brewery.

Parallel Stirred Immersion Coolers -

I have used both counter flow coolers(fig.5) and immersion coolers(fig. 6) over the years. I had an infection problem at one point that I could directly contribute to the counter flow cooler. This problem prompted me to build an immersion cooler. I won't discuss the pros and cons of each cooler type here, I would refer you to other Zymurgy articles on both their construction and the trade-offs and advantages of each design. In this article I will discuss some refinements I have made to my immersion style cooler. The typical immersion cooler is made up of a long (usually 10-50 feet) of copper tubing. I made my original cooler with about 50 feet of 3/8 inch tubing. It occurred to me that the liquid traveling through the cooler had probably accomplished the maximum cooling by the time it was through about half the cooler tubing. I reasoned that it would be better to have two 25 foot coolers in parallel than one 50 foot cooler. I reworked my immersion cooler so that the incoming cool water would be split into two 25 foot cooling sections, and then recombined at the output(fig. 7). This improvement did indeed improve the cooling. I brew 10 gallon batches in a 15 gal keg. My cooling time dropped about 20%. This got me in the 25-30 minute range. Flow and water temperature are very important here as well. The maximum cooling will always occur at max flow rate and with as cold as possible input water. After using this cooler over several batches I noticed that the coolers efficiency was also very dependent on whether the wort was moving or not. I would stand there by the kettle and sort of rock the cooler back and forth during the cooling cycle. In the name of automation I decided to add a motor driven stirrer to the cooler. The motor was obtained from Edmund Scientific for about $5 and a fan blade from a local hardware store was attached with a stainless 1/4 inch rod. The motor is a DC motor and driven with a small DC power supply. The kind that is used to supply power to small radios and tape players. The motors speed is very slow, I would say it's about 30 RPM. The speed isn't critical, the idea is to just keep the liquid moving, without aeration. Don't laugh at this idea until you give it a try. My cooling times are now about 20 minutes. This fast cooling is very desirable to minimize DMS. I would highly recommend using only DC motors and you should also have a GFI (ground fault interrupter) on any outlet near your brewery. Remember that "Water + Electricity = Death"

Automatic Water Heating device -

Would you like to cut down the amount of time required to make a batch of beer? This can be accomplished by having your mash strike water at the proper temperature when you are ready to start brewing. To build an automated water heater, you can place an electric heating element in a keg(fig. 8). This element should be an immersion heating element, like those that are in the bottom of your dishwasher. The heater should be about 1000-1200 watts for 110vac operation. This element will do the heating, so how do you control the temperature? The temperature setpoint can easily and cheaply be controlled with a temperature switch. The switch is mounted through the side wall of the keg and is wired in series with the power to the heating element. As the temperature rises above the temperature switches setpoint it will open up. When the temperature falls below the setpoint, the switch will close again, reapplying power to the heater. These temperature switches can usually be obtained from surplus dealers for about $5, I obtained one from C&H surplus. These switches can control up to 20 amps of current. Now all we have to do is plug this heating assembly into a timer of some sort for automatic start times. Make sure your timer is capable of handling the current drawn by the heater you are using. Now the night before brew day, you fill your hot liquor tank with cold water and set your timer for several hours before you get up in the morning. The timer will turn on and heat the mash-in water up to the desired temperature and maintain that temperature until you get up. Is this a frill? Yes, but it is one more item that you can use to cut down on the amount of time required to make all grain beer. It can also minimize the number of flame burners required in your brewery, and the necessity to move hot liquids from one kettle to another in small systems that only have one burner.

Updated: July 08, 1999.