Step 1. Test if the idea works.
R.I.M.S is Recirculating Infusion Mash System. The theory is you continuously pump liquor (water) through the mash and past a heating element to have more control over the mashing temperature and avoid variations within the mash. This helps get a better conversion at the temperatures you are aiming for. By nature, the system also has builtin Vorlauf which can assist in clarification.
To start with I purchased a stainless 50L (13GAL) boil pot and a stainless 40L (10Gal) mash tun pot. Then I cut out most of the base of the smaller pot and placed a stainless mesh into it. I used some scrap stainless square tube for ‘feet’ to keep the mash tun at the appropriate height inside the boil pot. After this I cut holes in the bigger pot and installed an appropriate pump with tubing to get the wort through the system, and a 2000W heating element which is tied it to a STC1000 to control the temperature.
It had some pretty major issues but it worked well enough to continue with the project. Onwards!
Step 2. The Frame
I built this with a cheap stick welder and some 2mm thick mild steel square pipe. It was my first real play with stick welding so its quite poor quality. Not poor enough to re-do, its strong, just not pretty.
The key points to note are the LPG Burner ring holder needed to be secure, at a good height off the ground, and at the right height to the base of the boiler. A bit of trial and error here. I ended up with about 4CM / 1.5 Inch. I think if I were to remake this I might make it adjustable, or a little bit lower.
Also one learning I had with the pulley was: I tried to position it right in the middle of the tower, but it should have been offset so that only one side of the pulley was in the middle, so that the actual wire was centered. at the moment the system pulls the mash tun out on slight angle.
Otherwise, I am quite happy with this structure.
Step 3. The Parts
- Big Pot / Boiler / Kettle  – This is a Stainless 50L (13GAL) pot I purchased off a local trade site for about $90NZD ($65USD) it has 4 holes drilled into it near the bottom for:
- BSP Bulkhead outlet from a plumbing supply store (for pumping) $10NZD
- 2000W Heating Element from my local brewing shop $65NZD ($45 USD)
- Stainless Analogue Dial Thermometer from an online brewing supply shop (for verifying digital temps) $50 NZD ($35 USD)
- Stainless Thermowell from ebay (for digital reading – attached to STC1000) $11 NZD
- Little Pot / Mash Tun – This is a Stainless 40L (10Gal) Pot that I cut out the bottom and installed a false bottom. About $60NZD ($42USD)
- Stainless Grill false bottom – second hand from a local winery
- Stainless Grill to spread wort across the grain bed – second hand from a local winery
- Pump – capable of handling 100 degree+ boiling wort at a good rate. From eBay $100NZD ($70 USD)
- Various copper piping, valves, Quick Disconnects and attachments about $150 ($110 USD) in total from eBay, local plumbing stores, and hardware stores
- Silicone Tube – for getting the pumped wort closer to the top of the mash from eBay $11NZD
- STC1000 for managing the temperature $65 NZD at the time – there are a lot of cheaper versions now.
- Scrap Stainless square pipe ‘legs’ to hold the mash tun above the element.
- Copper Wort Chiller from my local brewing shop $125 NZD ($90USD)
- Scrap hose for the Wort Chiller
- 3 Ring LPG burner – local hardware store  $65NZD ($45 USD)
- Winch for hauling up the mash tun from a local trading site $25 NZD
- D-clamps and stainless chain for winching the mash tun from the local hardware store $25NZD
- Mild Steel for the frame was about $50 NZD from http://www.wakefieldmetals.co.nz/
Total $900 NZD ish (or $660USD at the time of writing.) Over the course of about two years which is how long it’s taken to build this.
Step 5. Assembly
Most of the equipment is just assembled on as per the photo below.
The Big pot (boil pot) has 4 holes drilled into it for the hot wort output, the 2000w Element, the Thermometer and thermowell, otherwise no other modifications.
From the bulkhead (wort out) I run to a stainless steel ball valve for flow control, and I have my Quick Disconnects (amazing) going to the pump. which has its own little shelf to keep the pipes inline and outputs to its own stainless steel ball valve (This one I dont really use, I cant even remember why I wanted it) which goes to a copper riser pipe and has a silicone hose off the end. I may shorten this configuration, it doesn’t need to be this long.
Inside the boil pot are 3 pieces of square scrape pipe, about 7cm long to hold the mash tun up off the heating element etc. then the mash tun sits ontop of that. the mash tuns only modification is I cut out 4 quarters in the bottom and placed a stainless mesh in there to serve as the false bottom. I also have a similarly sized perforated stainless sheet on the top of the grains to help disperse the hot wort and avoid wells.
attached to the handles of the mash tun I have two D-Clamps holding a stainless chain for lifting it out. I bought a cheap boat winch which is completely overkill but the price was right, and this is mounted on the side and the handle also serves as a convenient place to store the mash tun after its been used.
More details in the Brew Day post below
The finished machine
The Grainfather ( NZ$1,350.00 ) Â is what inspired me to build this, if you don’t take my time into account (Building things is fun, OK 🙂 ) I think I did pretty well. Â I get a bigger capacity and had a lot of fun experimenting/building this. Knowing what I know now, I think I could build it again 25% cheaper, some fittings and piping didn’t make it into the final product and some parts are nice but not required (eg the Quick Disconnects and the Analogue Thermometer).
