Step Mash Controller
Disclaimer: The information contained herein is for the sole purpose of information and education. Build this project AT YOUR OWN RISK. I have NO responsibility whatsoever for any injury, death, legal issues, encounters with law enforcement, burnt beer, or damage to property of anyone operating or involved with using this step mash controller. In no event will the author be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from the use of, or in connection with the use of this step mash controller. Please do not attempt to build this without first consulting with an electrical professional.
Why?
Several months ago I purchased the Unibrau Mini. Overall I've been pretty happy with the system— it has a little trouble getting to a boil (definitely not a rolling boil), but that's more a product of it being 120v vs 240v. The controller is well built, uses an older model EZBoil, and includes a selector switch for a pump. Unfortunately, if you want to step mash it can only be done manually. The new DSPR310C controller can be set for mash steps, alarms, and timed events. Instead of just swapping out the controller I wanted to add several more features and extend the length of the element cord.
Bill of Materials
Most if not all of the materials can be found on Auberin. I purchased a few outlier items from Amazon and eBay. As always, if you are willing to wait several weeks you can find most of this on eBay from Chinese sellers for significantly less.
Enclosure
1. Aluminum project box
2. Rubber feet x4
3. Cable glands
4. 12/3 cord with 5-15 plug
5. 12/3 cord SJEOOW x10'
6. NEMA L6-30R plug
Internal electrics
1. 40A SSR
2. SSR thermal pad
3. SSR heatsink
4. EZBoil DSPR310C
5. 20A fuse
6. 120V panel mount outlet
7. DPDT lighted rocker switch
8. Selector switch 2NO x2
9. LED indicators x2
10. RTD extension wire x3'
11. Panel mount RTD male
Total cost with shipping was around $275
Schematic
This design is based on reinterpretations of what I've found around the web, brewing forums, chats with an electrician(my dad), and the base schematics provided by Auberin. I opted to keep things electrically simple, given it's on 120VAC, and use an SSR without a contactor.
More to come...
