This project started with the desire to move into all grain brewing. I wanted to keep the impact to my process at a minimum and do it in the most cost effective way possible without compromising the quality of the resulting beer.
My research began with the vessel that was going to be used as the mash tun. My decision was reached after reading feedback and discussions on several different coolers, converted kegs, and stock pots. I chose the Igloo 52 quart basic red cooler as my mash tun.
I chose this size and shape for the following reasons:
- Reliability for 5 and 10 gallon batches
- Affordability ($20.99 at time of purchase)
- Temperature Stability over long periods of time
- Catered to affordable manifold design and efficiency
Reliability Several discussions throughout the interwebs led to the realization that a 52qt design with a manifold suits 5 and 10 gallon batches. The primary concern is the capacity to hold a full grain bill for a 10 gallon batch plus the water needed to properly sparge. To date, I have had no issues with 10 gallon grain bills for moderate and low gravity beers. The 52qt cooler may be too small for a full 10 gallon high gravity beer.
Additionally, I decided my method of extracting the sugars from the grains would be batch sparging. There are concerns in many communities with the effectiveness of extraction in direct relation to the grain bed depth. With this size and shape cooler, I have never come across an issue with a 5 or 10 gallon batch and their respective efficiencies.
Affordibility This was by far the cheapest vessel to use at your local big store for $20.99. It already had a water drain, which was a very convenient port to convert over with a 1/2″ ball valve.
Temperature Stability, Manifold Design This cooler had great reviews for holding temperatures within 1°-2° over the course of 60 minutes. This claim has held very true and I’m completely satisfied.
With the manifold design that I settled on, this cooler was the best fit for how I was going to implement my design.
The Manifold Build
As mentioned in the previous section, I did have to modify the cooler with a ball valve fitting to accommodate the manifold. This version of the DIY article will not go into detail about that process, but may be revisited at a later time.
A very large part of my decision to build a manifold came from the book, How To Brew, by John Palmer (Brewers Publication, 2006). The manifold is made from Chlorinated PVC (CPVC) to withstand the mash temperatures and is sturdier than most of it’s screen counterparts. The biggest reason was the even distribution of the wort as it’s draining. As you can see in the picture below, I have tried to minimize the dead zones by making the drainage as even as possible. This is all outlined in Appendix E of How To Brew.
Parts needed to build this manifold:
- (4) 90° 1/2″ Elbow Joints
- (3) T 1/2″ Connections
- (2) 45°1/2″ Connections
- 1/2″ CPVC Pipe. Hardware stores sell them in predetermined length, I bought 3 of these and had plenty left over.
Use the diagram below to place the connections in the correct areas and the measurements to cut the pipe to the required lengths. I did not use any glue or adhesive to attach the pieces together. This was a part of the design to allow for proper dis-assembly and cleaning. It’s construction allows for structural integrity while stirring strike water in the mash. I have personally never had an issue with the manifold coming detached or separating during mashing.
I use the slot method as opposed to drilling holes. The slots are spaced 2/8″ inch apart and are only on the length portion of manifold. If you cut slots on the width portion of the pipe, refrain from cutting slits or holes on the pipe leading to the port. This pipe needs to stay intact to ensure suction is maintained to drain wort below the port level.