10 Gallon Igloo Cooler Mash Tun With Coldbreak Brewing False Bottom Review

A cooler mash tun is a cheap way to break into all grain brewing. I built my mash tun from a 10 gallon igloo cooler, a weld-less valve from Amazon and a false bottom from Coldbreak brewing. All in all it cost me about $105 to put together. Most hardware stores have their own branded versions so go with what is cheapest but double-check dimensions! 

Now onto the Igloo cooler:

The 10 gallon Igloo cooler (Amazon affiliate link) comes with a seat top lid that presses down to seal nicely. The Igloo cooler is sturdy with thick walls but also not too heavy. I tend to move my mash tun inside on cold days so extra weight is nice to avoid. The handles will easily hold the weight of a 6 gallons of water and 16 pounds of grains much better than your back will.

The thick walls keep my temperature steady for the full sixty to ninety minutes I mash. The one con here is with it being plastic is if you botch your mash water temperature then you’ll either have to add more water or go with the lower mash temperature. Make sure to fill the cooler with some warm water to both warm up the cooler and prevent warping.

The Igloo cooler started with the typical plastic smell but faded with a few washes. I’ve had no plastic off tastes in any of my beers. The walls have not stained at all or even been scratched from my paddle. Mine did come with a cup holder if you plan on using it as intended or repurpose it for something brew related.

PROS:

• Fairly cheap compared to stainless steel options
• Holds heat really well
• Many bulkheads available
• Durable

CONS:

• Can’t be heated
• Can warp or crack if temperature shocked

Verdict: The 10 gallon Igloo cooler is a great mash tun option for saving money on a multi-vessel all grain system.

Now onto the breakdown of the Coldbreak brewing false bottom:

The Coldbreak brewing false bottom (Amazon affiliate link) is built like a tank. It is constructed of good old 304 stainless steel. It features crosscut vents rather than holes. I haven’t tried another false bottom but the design has prevented grains from coming through on every batch so far. There’s plenty of room for a bazooka screen on the bottom if you really want super filtration. I like that there are no hoses or valves to bump into while stirring as the everything is below the false bottom.

The false bottom fits snugly within the cooler. There is plenty of room to get it in but no room for grain to fall through the sides. It works out nicely as I can dump my grain without the false bottom landing in the compost pile. A ring is present for when you want to pull it out of the cooler. The bottom of the false bottom consists of a good sized support ring. The welds aren’t perfect but are clean enough to avoid rust and strong enough for my beer gut body to stand on.

PROS:

• Stainless steel
• Holds the weight of even the heaviest grain bill
• Crosshatch allows wort to flow freely without grain getting into the boil kettle
• Easy to remove and clean
• Can be used in conjunction with a bazooka screen
• Flat bottom doesn’t interfere with stirring

CONS:

• Needs to be cleaned well before use
• Welds on support ring are just ok

Verdict: The Coldbreak brewing false bottom is sturdy and allows good flow without a stuck mash.

Now onto the CB-2PCB weld-less cooler bulkhead:

The CB-2PCB weld-less cooler bulkhead (Amazon affiliate link) is a good option for the 10 gallon Igloo. It is extra long inside so there is plenty of room to tighten the nut, attach a bazooka screen or use on a thicker walled cooler. Beware of some shorter bulkheads as you won’t be able to fully secure the nut inside let alone anything else. This one is truly long enough to fit any cooler I’ve ever seen.

The bulkhead is made of good quality 304 stainless steel and includes a silicone washer. You’ll need to use some TSP to get the oils off it. It wasn’t nearly as bad as my SS Brewtech Bucket to clean. The washer seals perfectly fine when you get it just tight enough. The handle does bump the wall of the Igloo cooler before “fully” closing but is actually closed enough to prevent any flow.

I attached this 1/2″ MPT x 3/8″ 304 stainless hose barb (Amazon affiliate link) to the bulkhead for my drain hose. The hose barb came fairly clean without needing any TSP. A quick wrap of plumbers tape is needed to get a tight seal and for easy removal for cleaning. The flow from the bulkhead through the nipple is fast enough with gravity. I actually use the same nipple on my 16 gallon Bayou brew kettle.

PROS:

• Stainless steel
• Long enough for any cooler
• Silicone O-rings seal really well

CONS:

• Lots of cleaning needed to remove machining oils
• Doesn’t come with a hose barb

Verdict: The CB-2PCB weld-less cooler bulkhead easily fits all coolers while allowing plenty of room for any attachments you could want.

It’s pretty straightforward but I figured I’d include a quick assembly guide for what I did on my mash tun. Your bulkhead or false bottom will vary but getting the cooler ready is pretty simple for most coolers. Make sure to take a picture of your bulkhead before disassembling for cleaning and insertion. A picture really is worth a thousand words when it comes to re-assembling any valve!

Assembling Your Mash Tun:

1. Remove lid and cut connecting strap if you want. I removed mine.
2. Hold the plastic spigot and turn the nut inside till it comes off. Pull off the spigot and you should have a nice clean hole.
3. ( Optional ) Drill a hole to expand spigot hole if your weld-less bulkhead is too big. Mine fit without drilling.
4. Use a wet rag to clean the hole. Mine had a few plastic shavings that were easily wiped away.
5. Disassemble your weld-less bulkhead and clean it well before installing. A soak in TSP and some warm water can remove any machining oils.
6. Insert bulkhead in according to directions of your kit and tighten your nut inside cooler. Make sure your silicone washer is in place and any other washers your bulkhead required.
7. Tighten fairly snug and do a leak test with warm water. Mine leaked so I had to adjust a few times to get it perfect. Don’t over tighten!
8. Clean off your false bottom with the same TSP water treatment. Boiling the false bottom can also help remove machining oils.
9. Pat dry and air dry for a bit. Insert false bottom into cooler and seal with lid till you are ready to brew.

Tips:

• Check homebrew supply stores or craigslist before building as it might be cheaper that way.
• Buy at least a 10 gallon cooler or suffer the dreaded equipment envy.
• Never pour any liquid over 175F directly in your mash tun.
• Remember to account for grain temperature loss when adding your water.