Alexius_II
New Member
Hello everyone, this is my first post, besides introduction 
Sorry for the very long post and large amount of photos, but I simply like to posts lots of pics, so that everything is clear to everyone. Hopefully.
I have been brewing for a year now, mostly 8L batches (around 2 gallons). My first few brews were extract (DME + hops) followed by another few using the BIAB method. I found BIAB method inconsistent and not really practical, so the solution was to build a proper mash tun. The whole process started after a friend found a 10L keg in some garage and gave it to me. It was the perfect size for a mash tun for my 8L batches of mostly 6% pale ales. I don't really want to fly sparge at this point, so batch sparging it is. Also, I wanted to have very precise temperature control and that meant lots of insulation and at least two temperature sensors.
First step was to cut away the outlet (bung) hole spring valve and the top opening. This was done using a dremel and about a dozen cutting discs. Edges were then smoothed using carbide burr bits and sandpaper. The big top hole is just the right size (18cm/7") to easily dump and mix the grains into water and leaves just the right amount of edge so a return hole could also be drilled on the top.
For the wort return, a barbed hose attachment + 90 deg. knee was used on the outside, and a "pressure fitting" with a bit of silicone tube simply pushed-in onto the threads on the inside. It fits snugly and takes about 5 seconds to replace the tube with shorter/longer bit if necessary, so the incoming stream is not too high or low to the mash level. Very simple and effective.
The outlet is also quite simple. A 21cm (around 8") long stainless steel braid with 22mm (7/8") OD is used. It fits perfectly into the outlet hole (22mm ID). The internal end of braid is plugged with a stainless bolt. Braid is folded inwards around a stainless ring (not visible, sorry), so the bolt screws on tightly.
The hole has a larger diameter on the outside and a smaller diameter towards the inside with a "step" with an edge at the middle. I thought of about 5 ways I could make this connection work, in the end I went with easiest and cheapest.
I made a small conical spring out of stainless wire, which inserts into braid and keeps it sturdy.
A silicone plug with a copper tube through the hole is then pushed in from the outside.
The whole plug fits perfectly in the hole and presses hard on the spring, which locks the braid in place (remember, there is a step inside the hole, which makes this possible). Initially I drilled two small holes on the side, so I could screw in a plate to prevent possible "unplugging" and/or spillage, but the fit is perfectly tight, there is no need for it.
Here is it, assembled with lid:
And a peek inside:
Next I made a wooden base for the whole thing. The pump and the valve (3-way T) are screwed in and 10cm (4") legs are added, so that the valve lever clears the table.
Next comes the bottom insulation layer (EPS, aka styrofoam), and the keg on top of it.
The first temperature sensor is then attached to the flattened socket on the copper outlet tube, simply by a steel tube clamp. Since the whole thing ends up inside the insulation it works perfectly.
The next layer of insulation is placed on, it has a hole and a "plug" to insulate the area around the outlet. The silicone tube is then also connected to the valve.
The remaining third layer is then placed on top, note the hole for the inlet tube on the side.
Here is a photo of all the interconnects used. Everything is assembled using parts of silicone tubing that fits snugly on copper and stainless parts. All metal parts have 10mm OD and silicon tubing has 8mm ID.
Next, a few words about the heaters. Two heaters are used, constructed out of copper tube with a layer of insulation (kapton tape) and wrapped with flat nichrome wire (a ribbon basically). Then another few layers of kapton tape followed by heatshrink tube. Both heaters are powered by 12VDC and put out 75W of heat each. It is a very small amount of power, compared to some of more conventional rims setups on this forum (a few kW of power), but works well because of good keg insulation. Power density is only about 3,8W/cm^2 (or 10W/in^2) and this is plenty to hold or slowly rise the temperature, but of course not enough for step mashes. I only do single infusions, so this is ok.
The first of both heaters is mounted between the valve and the pump:
...and the second one after the pump, towards the return inlet:
This upper heater has a temperature sensor on the top side, which is used as a safety feature. If this temperature rises to 5°C above other sensors, the heating is automatically turned off. This is useful in case the pump malfunctions or if flow is restricted due to stuck grain bed (so that heaters don't burn the wort).
The third and final sensor is attached on a short piece of a copper tube, simply by stretched silicon tube. It measures the "inlet" temperature.
The sensor is mounted just before the return hole, so that it measures the actual temperature of liquid, as it returns back to the tun. Sensor wire and silicone tube are routed via that hole through insulation, mentioned earlier.
And the last piece of silicon tubing is then attached to the "output" of the valve, which lets the wort flow to the pot via gravity.
A few words about the control box:
It is powered by 12VDC 240W power supply, arduino is used as the "brain". Pump is powered via pwm, using a and transistor, flow is set by a pot. Heaters are powered (switched) by a mosfet, according to return (inlet) temperature. It is actively cooled by a 60mm PC fan on the side. Here is a gut pic:
...and all the connectors at the back:
On the left side, the display shows, from the top to the bottom:
*temp. set by user
*temp. at the inlet
*temp. at the heater
*temp. at the outlet
And heater/pump status are displayed on the right side.
And as promised, a few words of this thing in action. First I did a test batch using some older grains, a strong English style IPA with 1% oat flakes. I wanted to nearly max out the tun, using 3kg (6 lb) of grain. I used brewsmith and estimated 70% brewhouse efficiency. Boy was I wrong... I calculated later I had 95% mash and more than 8% brewhouse efficiency. And on top of that, I missed my mash temperature. I intended to mash high, but was too slow mixing the grain in, so I lost 2 degrees there. In addition I forgot to turn heaters on for first 20 minutes, so another degree or so lost. Lessons learned, the beer was bottled a few days ago, with a substantial 8,5% ABV
And then I brewed a light APA. After mashing for 60 minutes, boiling water was added to reach 75C (mashout). Tun was then completely emptied, and filled with sparge water three times (pour in water, mix thoroughly, wait to settle, recirculate/vorlauf, empty completely, repeat). Recipe was made using 80% efficiency, everything went well, at the end calculated efficiency was 84%. Not bad, BUT my water is sadly very alcaline and not suited for light pale beers. With unadjusted water, my mash pH jumped to almost 6 and the last runnings had 6.5 pH and very low gravity, 1.009. It tasted fine, no obvious tannin extraction, but the numbers are something to work on. Next time I will be correcting my water profile for the first time.
Ok, a few pics of this APA brew. First waiting for the water temp to stabilise:
Next, a grain pic. I got myself a Mattmill kompakt, a very nice German mill, gap is set to about 0,9mm (0.035").
And a mash pic:
(it looks full, but it is only at around 75% of usable space)
Here come first runnings:
And the boil. I found this nice trick of preheating the coil online somewhere. It works very good, immersing the cooler does not kill the boil any more.
And the last pic, about 30 hours later:
This system appears to have greater efficiency than I initially expected, but for lighter beers water chemistry really needs to be adjusted. Bru'n water seems like a very nice tool for this and will be used next time.
This is about all. I know it is a lot of photos, maybe more than necessary, but I find it easier to show things using photos than words. I am open to all comments and critiques about everything. At the end of the day, it is quite a bit more complicated than biab, but offers me much more control and repeatability at expense of some extra time.
If I missed anything or something is not clear, please post a comment about it. English is not my first language, so there might be some strange words and sentences in this post. Sorry for that.
Best Regards,
Aleš
Sorry for the very long post and large amount of photos, but I simply like to posts lots of pics, so that everything is clear to everyone. Hopefully.
I have been brewing for a year now, mostly 8L batches (around 2 gallons). My first few brews were extract (DME + hops) followed by another few using the BIAB method. I found BIAB method inconsistent and not really practical, so the solution was to build a proper mash tun. The whole process started after a friend found a 10L keg in some garage and gave it to me. It was the perfect size for a mash tun for my 8L batches of mostly 6% pale ales. I don't really want to fly sparge at this point, so batch sparging it is. Also, I wanted to have very precise temperature control and that meant lots of insulation and at least two temperature sensors.
First step was to cut away the outlet (bung) hole spring valve and the top opening. This was done using a dremel and about a dozen cutting discs. Edges were then smoothed using carbide burr bits and sandpaper. The big top hole is just the right size (18cm/7") to easily dump and mix the grains into water and leaves just the right amount of edge so a return hole could also be drilled on the top.
For the wort return, a barbed hose attachment + 90 deg. knee was used on the outside, and a "pressure fitting" with a bit of silicone tube simply pushed-in onto the threads on the inside. It fits snugly and takes about 5 seconds to replace the tube with shorter/longer bit if necessary, so the incoming stream is not too high or low to the mash level. Very simple and effective.
The outlet is also quite simple. A 21cm (around 8") long stainless steel braid with 22mm (7/8") OD is used. It fits perfectly into the outlet hole (22mm ID). The internal end of braid is plugged with a stainless bolt. Braid is folded inwards around a stainless ring (not visible, sorry), so the bolt screws on tightly.
The hole has a larger diameter on the outside and a smaller diameter towards the inside with a "step" with an edge at the middle. I thought of about 5 ways I could make this connection work, in the end I went with easiest and cheapest.
I made a small conical spring out of stainless wire, which inserts into braid and keeps it sturdy.
A silicone plug with a copper tube through the hole is then pushed in from the outside.
The whole plug fits perfectly in the hole and presses hard on the spring, which locks the braid in place (remember, there is a step inside the hole, which makes this possible). Initially I drilled two small holes on the side, so I could screw in a plate to prevent possible "unplugging" and/or spillage, but the fit is perfectly tight, there is no need for it.
Here is it, assembled with lid:
And a peek inside:
Next I made a wooden base for the whole thing. The pump and the valve (3-way T) are screwed in and 10cm (4") legs are added, so that the valve lever clears the table.
Next comes the bottom insulation layer (EPS, aka styrofoam), and the keg on top of it.
The first temperature sensor is then attached to the flattened socket on the copper outlet tube, simply by a steel tube clamp. Since the whole thing ends up inside the insulation it works perfectly.
The next layer of insulation is placed on, it has a hole and a "plug" to insulate the area around the outlet. The silicone tube is then also connected to the valve.
The remaining third layer is then placed on top, note the hole for the inlet tube on the side.
Here is a photo of all the interconnects used. Everything is assembled using parts of silicone tubing that fits snugly on copper and stainless parts. All metal parts have 10mm OD and silicon tubing has 8mm ID.
Next, a few words about the heaters. Two heaters are used, constructed out of copper tube with a layer of insulation (kapton tape) and wrapped with flat nichrome wire (a ribbon basically). Then another few layers of kapton tape followed by heatshrink tube. Both heaters are powered by 12VDC and put out 75W of heat each. It is a very small amount of power, compared to some of more conventional rims setups on this forum (a few kW of power), but works well because of good keg insulation. Power density is only about 3,8W/cm^2 (or 10W/in^2) and this is plenty to hold or slowly rise the temperature, but of course not enough for step mashes. I only do single infusions, so this is ok.
The first of both heaters is mounted between the valve and the pump:
...and the second one after the pump, towards the return inlet:
This upper heater has a temperature sensor on the top side, which is used as a safety feature. If this temperature rises to 5°C above other sensors, the heating is automatically turned off. This is useful in case the pump malfunctions or if flow is restricted due to stuck grain bed (so that heaters don't burn the wort).
The third and final sensor is attached on a short piece of a copper tube, simply by stretched silicon tube. It measures the "inlet" temperature.
The sensor is mounted just before the return hole, so that it measures the actual temperature of liquid, as it returns back to the tun. Sensor wire and silicone tube are routed via that hole through insulation, mentioned earlier.
And the last piece of silicon tubing is then attached to the "output" of the valve, which lets the wort flow to the pot via gravity.
A few words about the control box:
It is powered by 12VDC 240W power supply, arduino is used as the "brain". Pump is powered via pwm, using a and transistor, flow is set by a pot. Heaters are powered (switched) by a mosfet, according to return (inlet) temperature. It is actively cooled by a 60mm PC fan on the side. Here is a gut pic:
...and all the connectors at the back:
On the left side, the display shows, from the top to the bottom:
*temp. set by user
*temp. at the inlet
*temp. at the heater
*temp. at the outlet
And heater/pump status are displayed on the right side.
And as promised, a few words of this thing in action. First I did a test batch using some older grains, a strong English style IPA with 1% oat flakes. I wanted to nearly max out the tun, using 3kg (6 lb) of grain. I used brewsmith and estimated 70% brewhouse efficiency. Boy was I wrong... I calculated later I had 95% mash and more than 8% brewhouse efficiency. And on top of that, I missed my mash temperature. I intended to mash high, but was too slow mixing the grain in, so I lost 2 degrees there. In addition I forgot to turn heaters on for first 20 minutes, so another degree or so lost. Lessons learned, the beer was bottled a few days ago, with a substantial 8,5% ABV
And then I brewed a light APA. After mashing for 60 minutes, boiling water was added to reach 75C (mashout). Tun was then completely emptied, and filled with sparge water three times (pour in water, mix thoroughly, wait to settle, recirculate/vorlauf, empty completely, repeat). Recipe was made using 80% efficiency, everything went well, at the end calculated efficiency was 84%. Not bad, BUT my water is sadly very alcaline and not suited for light pale beers. With unadjusted water, my mash pH jumped to almost 6 and the last runnings had 6.5 pH and very low gravity, 1.009. It tasted fine, no obvious tannin extraction, but the numbers are something to work on. Next time I will be correcting my water profile for the first time.
Ok, a few pics of this APA brew. First waiting for the water temp to stabilise:
Next, a grain pic. I got myself a Mattmill kompakt, a very nice German mill, gap is set to about 0,9mm (0.035").
And a mash pic:
(it looks full, but it is only at around 75% of usable space)
Here come first runnings:
And the boil. I found this nice trick of preheating the coil online somewhere. It works very good, immersing the cooler does not kill the boil any more.
And the last pic, about 30 hours later:
This system appears to have greater efficiency than I initially expected, but for lighter beers water chemistry really needs to be adjusted. Bru'n water seems like a very nice tool for this and will be used next time.
This is about all. I know it is a lot of photos, maybe more than necessary, but I find it easier to show things using photos than words. I am open to all comments and critiques about everything. At the end of the day, it is quite a bit more complicated than biab, but offers me much more control and repeatability at expense of some extra time.
If I missed anything or something is not clear, please post a comment about it. English is not my first language, so there might be some strange words and sentences in this post. Sorry for that.
Best Regards,
Aleš
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