Introduction: Grain Brewery
This isn't about brewing beer as such but how to make brewing kit for a complete grain brew that actually works. I have tried various grain bags etc. over the years without success. So, let's have another go and do it like the grown-ups do! A word or two of warning first. This project uses electricity, water and an idiot! If, like me, you are based in the UK our electricity hurts twice as much as it does in the US. It's dangerous stuff so be careful, it does kill!
The main components are four brew bins, three kettle elements and two thermostats that will switch 10 amps each. In this prototype I have already got a boiler, my grannies old Burco, it must be sixty and still going strong! If you don't have such a beast use a bin, drill the appropriate sized hole and fit a kettle element. Tip: Don't drill holes too close to the base, there needs to be enough "give" so the seal doesn't leak, the side wall needs to distort from "round" to "flat".
The thermostats or should I say "MH1210W Digital Temperature Controllers" do seem to work well but keep an eye on the switching temperature, they can go over and/or under by quite a few degrees (hysteresis) if the sensor isn't kept in the flow. I have also added a schematic of wiring as I have had them delivered without a diagram. Pins 1 and 2 are for switching current for the element. Pins 3 and 4 are supply (220-240v) in and 5 and 6 are for the temperature sensor. You will require a separate connector for the earth as one is not provided on the controller.
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Step 1: Mash Bin
Take one of the bins and cut out the base leaving a substantial lip. Get a sheet of perforated stainless steel and cut to fit inside the base. Drill and screw in place (stainless steel or nylon nuts/bolts). I had a couple of trial runs with some out of date grain using steel mesh. It clogged within seconds of circulating the water. A 30cm x 30cm perf. steel sheet off eBay worked well. The hole size is 3mm on 5mm centers, at £10 I still think it was a bit pricey! If your bin is bigger make sure a 30cm x 30cm will cover the hole made as this size sheet appears easy to get and you can cut it with a decent pair of snips.
This is the bin into which you will place your grain. This bin slides inside a second to which a pump is fitted. The one I used is a "12v solar hot water pump circulation high quality food grade" off eBay, I found a 12v 1amp supply in a box of bits. I use 10mm microbore copper onto a push fit 10mm "John Guest" bulkhead connector. If you look at the image of the complete setup you will see one of three stoppers I bolted to the mash bin to give adequate space under the perf. steel.
So, you should now have two bins fitted together with a sump separated by perforated sheet and a pump. We now need to circulate water through the grain and keep the wort at 66C. The heater/chiller bin is the last one to make.
Once I have finished circulating the wort, I lift the inner bin above a pair of draw cords (a bit more work needed on this part) so that I can drain and sparge (using water from the sparge bin) to make up my 23 litres of wort.
I have italicised above as I no longer do it that way. I have found that sparging with the bin left in position works just as well and it really saves on the hernia operations.
Step 2: Heater/Chiller Bin
Ignore the chiller bit for now, we want to circulate water at 66C through our grain, chilling comes later!. Take 10 metres of 10mm microbore copper pipe, it will arrive spooled so most of the hard bit is done. When I "lined" my bin (see picture) I did have to tighten the loops up a bit. This can be fiddly and much swearing is required but it is not that difficult. Next fit a kettle element (not to close to the bottom of the bin) and a tap, taking care not to puncture the tubing.
The thermostats are MH1210W's from guess where? What would I do without my favourite tat bazaar? I'm not sure just how legal these things are seeing as the labelling is all in Chinese but I've been using them in home projects for quite some time now without issue.
These thermostats will happily switch 10 amps so I use 2.4kw kettle elements (10 amps at 240v). Please make sure you do not overload any thermostat you choose for this job.
You are now set, connect the copper coil to the pump outlet and the return from the coil to a hole in the middle of the mash bin lid. Once the heater bin is full of water switch on the kettle element and set the thermostat to 66C. Put the sensor down the side of the mash bin so it is in the "sump" near the pump intake. Fill the mash tun with approx. 10 litres of water and turn the pump on. The heat exchanger will bring the water circulating through the mash bin up to 66C, the recommended mashing temperature. Tip, I actually set the temperature to 70C before adding the grain as this action brings the temperature down a few degrees. Don't forget to reset to 66C though once the grain is added!
Add sufficient water to the mash tun so the grain is just covered (see picture). Where do you get more water at 66C you ask - from your sparging bin!
Step 3: Sparging Bin
This is the final bin in the project. Fit a kettle element and the other thermostat and set to 66C. I use this this to top up the mash so it is just covered and later to sparge. Whilst this bin is being heated give it an occasional stir to make sure the water is evenly heated. If you don't have your grannies old Burco this doubles up for boiling. Please make sure that the bin you choose can cope with boiling water, if in doubt buy a proper boiler.
Step 4: Yeast
Why go to all this trouble? Because you want a pint that tastes good and not like that stuff your mate tried to poison you with last Christmas!!
Once you have your wort, you want the fermentation to start as quickly as possible, so make sure your yeast is ready for the job at hand. I use a flask with approx. 150ml of water and a cup of DME, boil and allow to cool. Pitch in the yeast and cover the neck with some foil. Agitation helps the yeast flourish so I have knocked up an agitator from a computer fan, two rare earth magnets and a bit of perspex. Pop a magnetic stirrer bar in the flask and away you go.
After 24 hours I gently pour off the DME and replace. The next day I start the brew, you can pour the DME off or pitch it all in. I always use light coloured DME so not to change the colour of the final brew.
If you have stayed with this so far the first trick to getting a good pint, other than nicking a good dollop of live yeast from your local brewery, is start your yeast off two days before you need it.
The second trick is to cool your boiling wort down quickly. Once you have finished your boil, and please take care, drain the hot water from the heater and dispose. You will see that all of my bins are fitted with taps to assist with draining, don't carry more hot water that you can manage safely, it's one thing to get wet, it's another to get scalded!
Step 5: Chiller
This is the heater placed over the sink, tap open and cold water pouring into the top. Syphon the hot wort through the copper coil into your brew bin. For me this gets the wort down to 25C in one pass so I can pitch in the yeast and fit the airlock. Fermentation starts immediately.
Bring the temperature down from the boil inside 20 minutes aids finished clarity and drops out proteins. Note the "in" arrow on the copper pipe. This goes to the bottom of the bin and "spirals" back up to the top, I think the direction gives the best heat transfer for heating and cooling but I wouldn't want to argue about it.
What's next, I need to tidy everything up. Electrics need to be boxed up and I always use a good quality earth leakage circuit breaker for the purposes of safety. Have you ever found a self priming syphon that doesn't warp in hot wort, that's the next bit of kit to find/make?
Self priming "ibble" added (hence italics above), please search for "jiggle syphon" or click above, this is a self priming syphon constructed from 10mm microbore copper.
Sterilisation, all the books say sterilise everything, ever seen them sterilise a brewery? Beer was invented as a way of drinking H2O that didn't kill you, the alcohol kills off the stuff that's out to get you. Get your fermentation started within an hour of coming off the boil and, in my experience at least, sterilisation becomes a thing of the past. Just keep kit clean. Here in the UK commercial breweries didn't really get started until the 1800's so brewing was the work of "ale wives" and in vilages several houses would offer ale for sale in their front rooms as and when they had stale beer ready (stale meant conditioned!).
Beer would be mashed in whatever came to hand that was vaguely waterproof. The water would be heated to approx 66C, at this temperature the water surface takes on a mirror like quality (no digital controllers back then) and the mashing would then proceed. The vessel would be covered with straw or similar to retain heat. Spices and other flavourings would be added (hops being a fairly modern addition) at the completion of this process and the grain would be reused for a second and possibly third time. The potential alcohol content reducing with each mash. The yeast would be active and ready to pitch as soon as the wort was cool enough, nature would take care of the rest. I really do get my bars rattled over sterilisation, it shouldn't be necessary if you don't leave your beer standing for a couple days waiting for your yeast tablets to start!