Yeast Stir Plate Update

I finally got my stir bar for my DIY stir plate. The stir plate kept throwing my stir bar so I had to modify the magnet mounting slightly. Originally I mounted the magnets to the outside of the washer mounted on the PC fan. I ended up moving the magnets inward so that they meet at the axis of the rotating fan. I also replaced the original 12VDC power supply with a 6VDC one. The 12VDC power supply was just a little too powerful even when the rheostat was turned all the way down. Even with the 6VDC power supply, I get a nice little vortex from 25% on up. I'll be brewing a Rauchbier this weekend. Rauchbier is a German Smoked Lager and since it's a lager it's best to have a good sized yeast starter. So I'll probably fire up the starter tomorrow night (Wednesday) and brew on Saturday. Here's video of the stir plate in action.


Another update 2/22/2011: After accidentally losing a stir bar down the disposal last year I ordered a larger one with a pivot ring.  The new one is slightly over an inch long and seems to work much better in that the stir bar rarely gets thrown now.

BCS-460 First Trial

My BCS-460 HERMS is fully functional. I brewed my first batch on it on 4/25 and everything went fairly well. The only problem I had was for mash out I'm raising the temp from the mash temperature (in this case 158 F) to 168 F. I was able to raise the temp over a period of about 10 minutes. Then I swapped hoses and routed the sparge water through the HEX. The problem was the temp of the HEX was actually higher than the 168 from heating the mash, so my sparge water was getting heated to approx 172. No problem, I just removed the copper coil from the HEX and the temp dropped to 168. I think next time I'll either reduce the temp of the HEX during mashout or I'll reduce the temp of the sparge water in the HLT.

Anyway, here are some pics I took during the inaugural brew session and also a few I took during construction. The quality isn't all that great in some. For the brew session I brewed indoors due to bad weather so the lighting isn't all that great.

Programming the BCS-460

For those not familiar with the BCS-460, it's a web-based process controller available from Embedded Control Concepts. The BCS-460 allows brewers to automate certain processes and closely control things like mash temperature. The goal is to brew more consistently with more easily repeatable results. So if I brew "Recipe A" on three separate occasions, the end product should be very similar each time.

I've setup the initial programming on my BCS-460. I'm sure I'll tweak the programming slightly after a few trials, but here is the logic as it exists right now. I've named Process 0 Single Inf Mash and it consists of the following states:

• System start
  
• Start Mash
  
• Dough-in
  
• Mash
  
• Mash Out
  
• Start Sparge
  
• Sparge
  

System Start

This state controls the heating elements in the Hot Liquor Tank (HLT) and Heat Exchanger (HEX). The water in the HLT will be heated for the strike water. The BCS-460 will heat the water to the desired temperature. This process is exited by clicking on one of the user input buttons.

Start Mash

During this state, only the HEX is on. This allows for transferring the strike water from the HLT to the mash tun, hose swaps, etc. This process is also exited by clicking on an input button. After the strike water is transferred to the mash tun, I refill the HLT with water to be used for the sparge.

Dough-In

This state powers on the HEX and HLT. The exit condition is based on a timer initialized at 12 minutes. When the timer gets to 0:00, the state is exited to the Mash.

Mash

During this state, the HLT, HEX, and pump are powered on. The mash liquid is circulated through the HEX in order to maintain temperature. The HLT's sparge water is heated to 170. This state is also controlled by a timer initialized to 60 minutes.

Mash Out

This state raises the mash temperature for mash out. The HLT, HEX, and pump are being controlled. Once the desired mash out temperature is reached, the state is exited.

Start Sparge

During this state the HLT and HEX are maintained at 170 degrees while the pump is turned off. This allows time for swapping hoses. This state is exited by clicking on a button.

Sparge

During this state the HLT is off, the HEX is on, and the pump is on and the sparge water is pumped into the mash tun. This state is exited by clicking on a button.

I still have a few plumbing fittings to buy as well as some electrical components. I hope to have these items pieced together within a couple weeks so that I can run the BCS-460 through some trials before my first brewing attempt.