RobB
Well-Known Member
For years my brewery has been very simple; just a 40L Birko urn, a voile bag and an over-the-side element for step mashes. After a few years of watching jealously from the sidelines as the Braumeister took off, I went to a friend’s BM brewday and was bitten by the recirculation bug.
I had the funds and spousal approval to buy a Braumeister but I couldn’t bring myself to buy one without at least trying to build my own recirculating system. What I ended up building borrows heavily from QldKev’s system as well as the Grainfather, except that I intend to use this as a full volume (i.e. no sparge) system.
Apart from working well, I wanted my new system to be as simple as possible to minimise the parts which would need cleaning and to keep the cost down if it all turned to crap and I ended up buying the Braumeister anyway. It also had to be built with my fairly limited skills and tools. For these reasons, I decided to recirculate downwards, mimicking the Grainfather and BrewEasy rather than the Braumeister.
I brew 12 litre (3 gallon) batches, but I think this system would work well for normal 19 litre batches even though it may require a sparge step to be added. Alternatively, you could apply the same ideas to different vessels.
The malt pot is the good old Big W 19 litre stock pot. Its thin walls make it cheap and easy to work with. Four stainless bolts make up the legs, the handles have been cut off and replaced with holes for hooks, and the bottom has been butchered to drain the wort. The slots were made with a 1mm cutting disk every 10 degrees and are 3cm long with 1cm spaces.......at least that’s what they were meant to be (don’t look too closely, I told you my skills were limited!). It’s pretty much a carbon copy of QldKev’s until you get to the big hole in the middle.
The hole is for the overflow drain, which is similar to the Grainfather’s except that their telescoping version was beyond my capabilities, so I will use different lengths of threaded pipe according to the size of my grain bill. No thread tape is necessary; some wort will flow through the mash and some will flow down the central pipe. If there is a leak path between the two, it’s not an issue.
This bit is important – Unlike the Braumeister and BrewEasy, which have very low density elements, urns like the Birko have high density elements. If wort proteins and flour are allowed to build up around a high density element, they can be scorched which will ruin your brew and quite possibly your element as well. Regardless of what your system looks like in the end, I strongly recommend that the wort flow is kept high when using a high density element. QldKev’s system lets the pump run flat out and he uses ball valves to balance the flow between the malt pot and a bypass. I do something similar, except that my bypass is the central drain. The pump still runs flat out, but I let gravity sort things out rather than plumb in two ball valves.
I need a top filter to stop grain disappearing down the central drain, and this was made using an Ikea spatter guard (of course!) and an HDPE chopping board which I cut up. Esky mush tuns are made from HDPE, so I am comfortable using this material in my mash, particularly since the product from which it was cut was intended for food preparation and is dishwasher safe. The frame is nice and rigid and the material was so easy to work with.
Here’s the assembled system – note the lack of valves. When it is not in the kettle, I simply keep the outlet hose elevated by draping it through one of the urn’s handles. The hose connectors are stainless and silicone nut and tail connectors from Nev at Online Brewing Supplies. I love these connectors! The thread doesn’t play a role in the seal, other than to squeeze an O-ring against the end of a male fitting, so again there is no need for tape. The pump is a Kaixin which puts out 19 L/min at zero head and about 15L/min once it is draped up onto the top filter.
The pot drains by sitting on a repurposed shelf from a bar fridge.
It’s all very simple, but does it work? Here is its maiden brew:
Dough in at about 40 degrees. My crush was fairly coarse and I added 5% rice hulls. The water volume was calculated such that when the wort reached the overflow pipe inside the pot, the wort level in the urn would be just above the bottom of the pot. This would give a good head difference to ensure flow through the grain, while ensuring that the wort wasn’t “raining” back into the urn. Opinions vary on HSA, but 90 minutes of constant rain is tempting fate.
I stirred the mash and let it sit for five minutes before turning on the pump. To my relief the level in the malt pot only crept up very slowly, indicating that most of the liquid was heading downwards through the mash. The level eventually rose to the drain, but the trickle going down there was far less than the 15 litres per minute gushing from the outlet.....for now........
By the end of a 52 degree protein rest, it was clear that more wort was going down the central drain. I decided to check for a stuck mash, which is easy to do with this set up. I simply directed the outlet hose down the gap between the urn and the pot and watched the wort level in the pot. When I saw that the wort level kept dropping below the top of the drain, I knew that wort was still flowing through the grain, just not as much as the pump could dump on top. That’s OK; that’s what this design is about. The mash takes what it can while the drain lets the pump run unrestricted. Based on the rate at which the wort level dropped during my test, the grain bed was draining top to bottom in about two minutes. I was happy with that so replaced the hose ready to ramp up to a beta rest. That’s when things got weird.
The strong flow from the pump created such a strong whirlpool that the wort was actually draining very slowly down the central drain while the outer edges of the whirlpool rose steadily to the top of the pot. I was worried that I had made my drain too small (half inch) to cope with the overflow, but then I noticed that slight adjustments to the position of the outlet hose made a huge difference to the wort level above the drain. I settled on a high tech solution: I dropped a small drinking glass onto the top plate to act as a baffle against the whirlpool. The result was amazing and immediate. The wort level dropped right down with only a very sedate trickle going down the drain.
Having to tame the whirlpool was the only drama during this maiden run. I stepped the mash to beta (62), alpha (72) and mash out (78) and was left with beautifully clear wort.
I’m looking forward to adding a brain to this system. I managed the mash steps manually by turning the element on until I hit the desired temperature, then backing off the dial until the element clicked off. This kept me within 1 degree of my target for steps as long as 30 minutes. I wasn’t sure whether the urn’s thermostat would be up to the job, but with the whole wort volume recirculating every two minutes, I’m guessing that the temperature throughout the mash was very even and this kept the element from constantly flicking on and off – another benefit of rapid flow.
When I lifted the malt pot (note to self, find a lower brewing surface!) the wort drained within minutes. I was a couple of litres short, so I tipped some cold water over the top filter to give the grain a rinse. Pre-boil efficiency was 82%.
The wort I collected at the end of the boil was the clearest I have ever produced and I was able to leave the break behind easily.
The whole build was easy, fun and fairly inexpensive. For about $200 I turned my urn into something pretty special. A lot of brewers seem to be building their own recirculating systems, so I hope I have provided some food for thought.
I had the funds and spousal approval to buy a Braumeister but I couldn’t bring myself to buy one without at least trying to build my own recirculating system. What I ended up building borrows heavily from QldKev’s system as well as the Grainfather, except that I intend to use this as a full volume (i.e. no sparge) system.
Apart from working well, I wanted my new system to be as simple as possible to minimise the parts which would need cleaning and to keep the cost down if it all turned to crap and I ended up buying the Braumeister anyway. It also had to be built with my fairly limited skills and tools. For these reasons, I decided to recirculate downwards, mimicking the Grainfather and BrewEasy rather than the Braumeister.
I brew 12 litre (3 gallon) batches, but I think this system would work well for normal 19 litre batches even though it may require a sparge step to be added. Alternatively, you could apply the same ideas to different vessels.
The malt pot is the good old Big W 19 litre stock pot. Its thin walls make it cheap and easy to work with. Four stainless bolts make up the legs, the handles have been cut off and replaced with holes for hooks, and the bottom has been butchered to drain the wort. The slots were made with a 1mm cutting disk every 10 degrees and are 3cm long with 1cm spaces.......at least that’s what they were meant to be (don’t look too closely, I told you my skills were limited!). It’s pretty much a carbon copy of QldKev’s until you get to the big hole in the middle.
The hole is for the overflow drain, which is similar to the Grainfather’s except that their telescoping version was beyond my capabilities, so I will use different lengths of threaded pipe according to the size of my grain bill. No thread tape is necessary; some wort will flow through the mash and some will flow down the central pipe. If there is a leak path between the two, it’s not an issue.
This bit is important – Unlike the Braumeister and BrewEasy, which have very low density elements, urns like the Birko have high density elements. If wort proteins and flour are allowed to build up around a high density element, they can be scorched which will ruin your brew and quite possibly your element as well. Regardless of what your system looks like in the end, I strongly recommend that the wort flow is kept high when using a high density element. QldKev’s system lets the pump run flat out and he uses ball valves to balance the flow between the malt pot and a bypass. I do something similar, except that my bypass is the central drain. The pump still runs flat out, but I let gravity sort things out rather than plumb in two ball valves.
I need a top filter to stop grain disappearing down the central drain, and this was made using an Ikea spatter guard (of course!) and an HDPE chopping board which I cut up. Esky mush tuns are made from HDPE, so I am comfortable using this material in my mash, particularly since the product from which it was cut was intended for food preparation and is dishwasher safe. The frame is nice and rigid and the material was so easy to work with.
Here’s the assembled system – note the lack of valves. When it is not in the kettle, I simply keep the outlet hose elevated by draping it through one of the urn’s handles. The hose connectors are stainless and silicone nut and tail connectors from Nev at Online Brewing Supplies. I love these connectors! The thread doesn’t play a role in the seal, other than to squeeze an O-ring against the end of a male fitting, so again there is no need for tape. The pump is a Kaixin which puts out 19 L/min at zero head and about 15L/min once it is draped up onto the top filter.
The pot drains by sitting on a repurposed shelf from a bar fridge.
It’s all very simple, but does it work? Here is its maiden brew:
Dough in at about 40 degrees. My crush was fairly coarse and I added 5% rice hulls. The water volume was calculated such that when the wort reached the overflow pipe inside the pot, the wort level in the urn would be just above the bottom of the pot. This would give a good head difference to ensure flow through the grain, while ensuring that the wort wasn’t “raining” back into the urn. Opinions vary on HSA, but 90 minutes of constant rain is tempting fate.
I stirred the mash and let it sit for five minutes before turning on the pump. To my relief the level in the malt pot only crept up very slowly, indicating that most of the liquid was heading downwards through the mash. The level eventually rose to the drain, but the trickle going down there was far less than the 15 litres per minute gushing from the outlet.....for now........
By the end of a 52 degree protein rest, it was clear that more wort was going down the central drain. I decided to check for a stuck mash, which is easy to do with this set up. I simply directed the outlet hose down the gap between the urn and the pot and watched the wort level in the pot. When I saw that the wort level kept dropping below the top of the drain, I knew that wort was still flowing through the grain, just not as much as the pump could dump on top. That’s OK; that’s what this design is about. The mash takes what it can while the drain lets the pump run unrestricted. Based on the rate at which the wort level dropped during my test, the grain bed was draining top to bottom in about two minutes. I was happy with that so replaced the hose ready to ramp up to a beta rest. That’s when things got weird.
The strong flow from the pump created such a strong whirlpool that the wort was actually draining very slowly down the central drain while the outer edges of the whirlpool rose steadily to the top of the pot. I was worried that I had made my drain too small (half inch) to cope with the overflow, but then I noticed that slight adjustments to the position of the outlet hose made a huge difference to the wort level above the drain. I settled on a high tech solution: I dropped a small drinking glass onto the top plate to act as a baffle against the whirlpool. The result was amazing and immediate. The wort level dropped right down with only a very sedate trickle going down the drain.
Having to tame the whirlpool was the only drama during this maiden run. I stepped the mash to beta (62), alpha (72) and mash out (78) and was left with beautifully clear wort.
I’m looking forward to adding a brain to this system. I managed the mash steps manually by turning the element on until I hit the desired temperature, then backing off the dial until the element clicked off. This kept me within 1 degree of my target for steps as long as 30 minutes. I wasn’t sure whether the urn’s thermostat would be up to the job, but with the whole wort volume recirculating every two minutes, I’m guessing that the temperature throughout the mash was very even and this kept the element from constantly flicking on and off – another benefit of rapid flow.
When I lifted the malt pot (note to self, find a lower brewing surface!) the wort drained within minutes. I was a couple of litres short, so I tipped some cold water over the top filter to give the grain a rinse. Pre-boil efficiency was 82%.
The wort I collected at the end of the boil was the clearest I have ever produced and I was able to leave the break behind easily.
The whole build was easy, fun and fairly inexpensive. For about $200 I turned my urn into something pretty special. A lot of brewers seem to be building their own recirculating systems, so I hope I have provided some food for thought.
