A few weeks ago, I was able to treat our readers with a behind the scene’s glimpse into the construction of our new 1/2 BBL mash tun. Our custom built wood-clad beauty ended up being just about everything I had hoped that it would.

MLT Done

In early use, it has performed beyond expectations, and we are very excited to be able to put it through even more paces in the months to come. I also was able to show you our new 25 gallon kettle, which…while by no means fancy…has also performed exceedingly well in early use.

Which brings us to the next key component in our expansion…our fermenter.

Producing more mash and wort is great…but to do it right, you need somewhere for the true magic to happen. We needed a new mash tun that could match our increased scale, and provide us all the features we needed and wanted to be a better and bigger brewery.

Sure, we could just use multiple buckets or carboys, as we have done in the past with larger brews, but it’s time to go big or go home.

So go big we did.

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We started off with a 15 gallon fully draining plastic induction tank purchased at Rural King. Not sure what these are intended to be use for…but the material and shape are perfect for our purposes. The tank is similar in shape to stainless steel conical fermenter, but can be had at a fraction of the price – less than $75 brand spanking new (including shipping). Since we are by no means material snobs, and since all our fermentation up to this point has been in plastic containers anyway, this seemed like a perfect fit for our needs and our wallets.


In addition to its geometry and price, another huge plus of this tank is that it comes with lines marking every 1/2 gallon which are actually fairly accurate…at least in the one we purchased. Not sure what the exact capacity for this tank is, but it has measurements up to 16 gallons, and headspace above that for an additional gallon or two. Plenty of room for a full batch of beer and its krauzen.

The bottom of the tank has female pipe threads which were the perfect fit for a 1 1/2″ PVC coupler. It was a snug fit, but with the help of a big ass pipe wrench, I was able to make pretty short work of getting everything snugged together.


The tank came with a steel hose clamp around the drain to apply additional pressure on the coupling. I don’t know how necessary this really is, but I didn’t want to take any chances…it is still plastic after all, and plastic can stretch given sufficient pressure. As such I tightened the clamp as tight as I could get it.

One of the greatest benefits of a conical fermenter is that it eliminates the need for a second receptacle for secondary fermentation and aging. Instead of carefully siphoning your clear beer off of the pack of sludge at the bottom of one fermenter and into a second fermenter, you can just dump the trub out of the bottom. During the first couple weeks of fermentaiton, the yeast, hop residue and general gunk will all settle into the cone, and when your fermentation has reached a point that you are ready to get rid of said gunk, you can just open a valve and flush it out.

But to do that, you need a valve.

Sticking with our plastic motif, we added a 1 1/2″ to 1″ reducer to our previously installed coupling. To that we added an elbow and a ball valve. The assembly was affixed together using PVC glue and primer.

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While this valve is handy for dumping crud, it is not what we want to use for transferring our beer when it is complete. Gunk will still remain even after our primary dump out, and that’s the kind of stuff we would prefer to keep out of the keg.

As such we installed an additional, albeit much smaller, drainage/racking port midway up in the cone. Adapters were added to the ball valve to reduce the 1/2″ NPT threads down to a 1/4″ flare…the same size used on our keg connectors, which will allow us to drain directly into our cornies.

An additional benefit of the racking port is that we can now test the gravity of our beer on a more regular basis, without removing a lid or bung, or having to sanitize a wine thief. Open the port, fill a cup with just enough for a taste and a refractometer reading, and be on your way. No fuss…no muss.

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While I was busy drilling holes, I thought it would also make sense to install an additional bulkhead for a 30 cm stainless steel thermowell.

Here’s a glimpse of the inside:

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Because the racking port was installed onto the actual cone portion of the tank, the inlet of the bulkhead angled upward towards the center of the tank. As a result, the port was still going to leave more fluid behind in the tank that what I would have liked. To compensate for this, I added some small bits of CPVC to start the inflow lower than it would have otherwise. There will still be some liquid left when all is drained out this way, but not so much that we can’t live with it. Plus, the stuff at the very bottom will probably be more sediment heavy than we care to keg/bottle anyways.

At this point, let me make a quick note on our materials. I am not a stainless snob. Never have been, never will be. For most brewing purposes I am none to shy about using copper or aluminum…or even plastic…as long as the materials adequately and safely suited the needs of the process. Every material has its pluses and minuses, and when cared for and used properly, can be used to great effect. Function over form after all.

This though, is not one of those cases. If I am going to expose our beer to any metal for an extended period of time…such as with fermentation…it will always be stainless. Copper is a great material for many uses. It is incredibly thermodynamic, and it is even naturally antimicrobial…but it does have one major weakness…acid.

Copper corrodes in acid, and beer is very acidic. To minimize risk of any copper leaching into our beer, we do not use it in fermentation.

Hence the use of a stainless steel thermowell and a CPVC pickup tube.

Moving on.

A stand for our fermenter was fashioned using some 2×3 pine boards. A hole just slightly smaller than the cylindrical portion of the tank was cut into some plywood.

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To make this all a bit easier to move around, caster wheels were added to the bottom of the stand.


A blowoff tube assembly was created from CPVC and a barbed hose connector and attached to the lid of the fermenter.

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A temperature control unit was wired up, and the probe was inserted as far as we could get it into the thermowell, along with generous amounts of Desitin. No devices are currently being manipulated by the controller, so it is really just a fancy thermometer…but it’s nice to have the option in case we need it down the line. In the meanwhile though, Brian has an easy way to see and track the temperature of our fermentation.

And here it is in action:


This also gives us a rough idea of how fermentation is doing. Fermentation generates heat, and Brian’s basement maintains a pretty constant temperature around 67-68 degrees year round. This pic was snapped about 24 hours after the yeast was pitched, so we can see just from the temp that our little friends were busy doing their thang.

Which brings me to the one biggest negative about this project as it currently stands…a general dependance on air temperature for proper fermentation. We don’t have a fridge or freezer big enough to hold this beast, so we are left with no other option than to do our fermentation in the basement. We also have no means to cold crash, which will make our filtering assembly more important than ever…particularly with our lighter beers where clarity is of the utmost desirability.

Time will tell whether this is an issue or not. If it is, rest assured we will be back to the drawing board for another round of brewery construction.

If it’s not…we’ll still be back to construction…just for fermenter #2.