This is the third post in a five part series on the updates made to my beer stand for the Jan 3rd brew. Here are links to the previous post:

• Brew Stand Update #1 - The Stand
• Brew Stand Update #2 - Panel, Wiring, and Power
• Brew Stand Update #3 - Gas and Water Control
• Brew Stand Update #4 - Oxygenation and Probes

Inline Oxygenation

I have been putting off this upgrade for a while and the electronics upgrade seemed like the perfect time to add the convenience. My primary concerns for adding inline oxygenation were:

1. How to control the amount of infused oxygen without visual feedback. This is important for getting the right amount of oxygen in the wort, cause too much is a waste, and in some cases detrimental. Controlling the amount of oxygen is also important for reproducibility. 
2. How to contain and feed the oxygen stone with disposable oxygen tanks so that it is convenient 
3. How to clean the oxygenation assembly easily without hassle.
   

For number one, I decided to build a little regulation assembly, complete with pressure gouge. This works by using a 1/8 inch to 1/4 inch NPT converter that goes from the disposable oxygen regulator to a 3-way 1/4 inch NPT union. The top of the union is connected to a pressure guage (max 30 psi), the right is connected to the regulator, and the bottom connected to a small ball valve. Now with the combination of the regulator, pressure gauge, and ball valve I can control exactly how much gas is being let into the wort. The gauge gets readings with both static and dynamic pressure, so it should be pretty easy to establish a workable PSI range for oxygenating.

For number two, I used the platform used by the chiller to also hold the disposable tank. I attached a big galvanized u-bolt that barely wraps around the tank holding it in place against the stand. It has enough contact to hold it in place but also allows me to remove it when empty. In addition to this, I have attached a stainless steel quick disconnect to the end of the oxygen regulation assembly. This allows for the assembly to easily be detached from gas source for removal of either device.

For the oxygenation assembly itself, I went with one sold by MoreBeer that has two stainless steel tees, connected with a small stainless nipple. The oxygenation stone screws into one end of the tees and has a 3/8 tube connection for the gas on the opposing side. On the opposite side of the assembly a brew probe is screwed in with a 2 in probe to take temperature readings. This leaves one 1/2 inch NPT port for the wort inlet and one for the outlet. The inlet is connected to the therminator chiller using a stainless steel quick disconnect and the outlet has a plastic quick disconnect with shutoff for a tube connection to the fermentor.

Probe Management

I struggled for a while on the best way to wire the stand. Once I decided on the position of the panel this got a little easier, but still left a few decisions to be made. My goal was to ensure that kettles could be moved fairly easily from the stand without much hassle. The main issue being that the HLT was going to have two connections (probe and float switch) and the mash one (probe), which called into question how I manage the wires. Instead of having long wires dangling from underneath the stand I decided to have the three movable connections wired directly to an outlet box. This way I could embed additional quick disconnects into this outlet face which allowed me to remove all of the HLT and mash wires easily. I placed the box under the mash platform to try and protect it from water. I'm hoping this will be enough cover, but if not I have some plexiglass I can use to create a splash guard. The outlet box is also positioned in a place that will allow the HLT probe to reach the back of the kettle for HERMS temperature control which will be very useful.  The only other issue of concern is heat from the burners melting the wires. Right now they seem to be far enough from the heat source. If it does turn out to be a problem, I plan to do a little cable management with galvanized pipe to help shield some of the wire from the flame. The other option is to put some heat and flame resistant heat wrap over the wired for protection. 

The only other piece to the puzzle is the float switch plug. To make this HLT  wire free I connected a female quick disconnect to the float switch itself and embedded it into a 1/2 inch NPT coupler that is attached to the external portion of the float switch. The coupler was filler with hot glue to keep the connector in place and allow for easy wire removal. This works surprisingly well.

Next Brew Stand Update Post

Next post I will be going over everything that remains. Should include things like stand power management, pump mounting, and any other odds and ends.