Simple SSVR-controlled e-BIAB rig

[pogden]

It has taken WAY longer than it should have for me to get to this point, but last weekend I was finally able to take my new brew rig for a test run. I've been spending a lot of time on HBT since getting back into brewing a couple of years ago. Last year I built a stir plate (had to figure out how to do that with a 4-wire PWM fan) and an fermentation chamber based on an STC-1000 and a Whirlpool 7.2cf chest freezer.

I also started mulling over what I wanted in the way of an all-grain setup. My objectives were as follows:

• Electric powered
• Capable of brewing 5-6 gallon batches
• Compact and storable
• Easy cleanup
• As simple as possible (no pumps, purpose-built sculpture, etc.)
• Fun to build

I decided early on that BIAB seemed like a good place to start - fewer vessels to store and clean. PID-based controllers are fascinating and definitely the way to go in a 3-vessel system, but in a BIAB setup it just seems to me that a knob is all that's needed. About the time I was ready to start building a PWM-based controller, Auber came out with their solid state voltage regulator.

So, here's what I came up with. The vessel is a bottom-drained e-keggle with a single 5500W element driven by a SSVR-based controller. The voltmeter/ammeter looks a bit blingy but it's actually there to give me an indication of the power that is being supplied to the element (the relationship between knob position and power output is non-linear).

There are a few more pictures in my gallery (use the link in my sig).

 

[241]

Neat. Different. Good work!

 

[passedpawn]

Really nice build. Where does that giant dial come from? Is there a pot behind it?

 

[pogden]

One thing about e-BIAB that concerns me is maintaining temperature during mash. Using a PID is an obvious solution but it seems that it works best with circulation, which introduces another problem: how to prevent the bag full grain from getting sucked down onto the hot element. This seems to be a problem for some guys and not for others, but I was sort of hoping to avoid it altogether by preventing as much heat loss as possible by insulating the keggle with a KegSkin.

During my hot water test run yesterday I learned that the KegSkin by itself will not be sufficient to maintain mash temp. What I did learn is that a very small amount of power (~1 amp) is required to keep the temperature steady for an hour or more. Granted, that's with plain water; a bag full of grain will probably impede convection, requiring at least some stirring, which will cause heat loss, which will require more heat, ... Something to sort out during my first brew, hopefully next weekend.

 

[pogden]

Really nice build. Where does that giant dial come from? Is there a pot behind it?

Thanks, PassedPawn!

The dial plate comes with the 330K Ohm pot that comes with the Auber SSVR (the exact pot supplied depends on the voltage and frequency of the power to be regulated, but you select this when you order the part).

The dial plate is just a visual indication of dial position. Output does not increase proportionally with dial position (that is, 30 on the dial is not necessarily 30% power).

 

[Epimetheus]

Beautiful build! Bookmarked.

Is that an inexpensive digital food thermometer to the left of the kettle? They have never been within 10F for me. This is in comparison to a lab-quality glass thermometer. You may be more fortunate.

The large thermal mass of a full BIAB batch helps reduce temperature fluctuations. I have a smaller 8 gallon kettle and insulated it the best I could to help maintain the temp. The sides are wrapped in 3 layers of Reflectix and could use another. The lid has 2 layers. When I use a heatstick, the kettle sets on a folded towel to insulate the bottom. The R value of a Kegskin is less than Reflectix but you have a large element to supply heat.

 

[passedpawn]

The dial plate is just a visual indication of dial position. Output does not increase proportionally with dial position (that is, 30 on the dial is not necessarily 30% power).

That's interesting. Was there documentation that came with the SSVR indicating the relationship between the dial value and the duty cycle or % power?

 

[pogden]

Beautiful build! Bookmarked.

Is that an inexpensive digital food thermometer to the left of the kettle? They have never been within 10F for me. This is in comparison to a lab-quality glass thermometer. You may be more fortunate.

The large thermal mass of a full BIAB batch helps reduce temperature fluctuations. I have a smaller 8 gallon kettle and insulated it the best I could to help maintain the temp. The sides are wrapped in 3 layers of Reflectix and could use another. The lid has 2 layers. When I use a heatstick, the kettle sets on a folded towel to insulate the bottom. The R value of a Kegskin is less than Reflectix but you have a large element to supply heat.

Thanks, Epimetheus.

The remote-probe thermometer is from Thermoworks, the same guys who make the Thermapen. I calibrated my Thermapen when I got it (well, I checked it, but it required no adjustment). I checked the oven thermometer against the Thermapen at 74F and and 160F yesterday and they were spot on. Though I hear you - I need to remember to check that often.

Thanks for the info on your setup and Reflectix vs. KegSkin R-value. Maybe I'll try some Reflectix as well, though my first thing will to see whether a small amount of heat can be used to maintain the temp effectively.

 

[pogden]

That's interesting. Was there documentation that came with the SSVR indicating the relationship between the dial value and the duty cycle or % power?

No, not really. But the description of the SSVR on the Auber website does describe this. It says that the "middle section" (I'm guessing 35-65?) is more sensitive due to the sine waveform of the AC power.

I need to play with it some more, but it seemed VERY sensitive at the lower end (~10) where just moving the dial a hair was enough to change the reading on the ammeter from 2A to 1A.

 

[KPSquared]

Wish I would have seen this before I bought my PWM stuff. Very nice.

Where did the stand come from?

 

[pogden]

Where did the stand come from?

It's my handy old Black & Decker Workmate 200 with a table top made from a scrap piece of 3/4" MDF with some 1/8" cork ($10 for a roll at Lowes) glued on top.

The Workmate jaws clamp onto a cleat made of scrap 3/4" particle board that I screwed into the underside of the table top. The whole thing is nice and stable, but at the end of the brew day the top comes right off and the Workmate folds up flat for storage.

In fact, the Workmate by itself would make a decent brew stand, and the bottom drain and valve assembly would fit nicely through its open jaws, making the red "Keg Spacer" unnecessary. The extra work surface is nice, though.

 

[jeffmeh]

I can't tell from the photo, but if you haven't already done so, insulate the lid. That's where most of the heat loss will occur.

 

[pogden]

I can't tell from the photo, but if you haven't already done so, insulate the lid. That's where most of the heat loss will occur.

I haven't done anything fancy, yet. But I did put a big folded-up towel on top during the "mash test" (after the temp started to drop), and it seemed to help.

I've been pondering a better solution, but haven't come up with anything yet. Ideally, it would conform tightly to the contour of the lid and the domed rim of the keggle that the lid rests on, yet be easy to remove.

Or, maybe just a couple of circles of Reflectix with slots cut in the center to allow the lid's handle to poke through?

 

[Brewing_on_the_Internet]

Your build looks very nice.
What do you do about trub?
Is there any way to filter the trub?

 

[Weissbier]

Awesome job Pogden! I just moved away from my SSVR BIAB setup to a PID to maintain mash temps. As of now I still like the way the SSVR maintains a boil.

I ordered that same volt/ammeter about two weeks ago. Did you bring each hot lead to the voltage input and pass one leg through the transformer just before the element?

 

[pogden]

Your build looks very nice.
What do you do about trub?
Is there any way to filter the trub?

Thanks, Brew.

I'm glad you asked, but I really don't know. I have yet to brew anything besides hot water as I just got my power supply sorted out last Sunday. I'll know more after next weekend, hopefully.

I will use a hop sock during the boil, and a bit of Irish moss at the end. When the boil is done I'll drain 5gal of wort into a waiting corny keg (perhaps through a paint strainer, just to see what I can catch), seal it, invert it to sterilize the lid, then stand right-side up in my pool to chill. The next day, I'll push whatever trub I can out with CO2, open the corny, oxygenate, pitch, reseal, and push it all slowly to my quarter-barrel sanke fermenter.

I am mildly worried that the bottom drain on my keggle will clog, and a bit more concerned that the corny dip tube will. I'm prepared to shorten the dip tube if needed to avoid this, and I'm fine with leaving a quart or more of trubby chilled wort behind.

 

[pogden]

Awesome job Pogden! I just moved away from my SSVR BIAB setup to a PID to maintain mash temps. As of now I still like the way the SSVR maintains a boil.

I ordered that same volt/ammeter about two weeks ago. Did you bring each hot lead to the voltage input and pass one leg through the transformer just before the element?

Thanks, Weissbier. I saw your thread about boil control with your PID - I hope you get that sorted out.

The hot leads are connected to extra spades on the C1/C2 (coil) terminals of the contactor, so the meter is only powered when the switch is on. Then, one of the 10 gauge hot lead leaving the output side of the contactor runs through the transformer to the load side of the SSVR. I posted some pics of the inside of the controller box in my gallery, see the link in my sig.

 

[Carlscan26]

The next day, I'll push whatever trub I can out with CO2, open the corny, oxygenate, pitch, reseal, and push it all slowly to my quarter-barrel sanke fermenter.

Aren't you going to leave yeast behind if you don't push the entire contents?

 

[pogden]

I was asked via PM about a parts list and a wiring diagram. Here's the parts list in PDF format, though I'm not sure the links are working right.

I used a 25A SSVR, but Auber now sells a 40A one. The 25A part is probably okay (a 5500W element draws less than 23A), but many people here recommend using a higher-rated part, and if I had it to do over again I would go with the 40A.

I drew the wiring diagram for this controller on my whiteboard and I *think* I may have a picture of it somewhere. Meanwhile, I'll post a few pics of the inside of the controller.

View attachment SSVR_e-BIAB_controller_parts_list.pdf

 

[KPSquared]

Just looked through your pics. Did you build that beautiful element enclosure or where did that come from? It looks so clean!

 

[pogden]

Aren't you going to leave yeast behind if you don't push the entire contents?

I suppose a few will settle onto the trub bed, but won't most of them still be in suspension (and therefore be transferred)? I expect the transfer to take at most maybe 10 minutes after pitching.

 

[pogden]

Just looked through your pics. Did you build that beautiful element enclosure or where did that come from? It looks so clean!

There are definitely guys on this forum with the skills (and equipment) to make something like that, but I'm not one of them! I bought it from Brewers Hardware - look under RIMS tubes, I believe.

I like it a lot, but it just might be the single most expensive part in my entire system. I wanted to be able easily remove the element from the kettle during cleanup and this seemed to be the way to go.

Silver-soldering the matching tri-clover ferrule after dimpling the keggle was kind of satisfying, too. That sounds wrong ...

 

[KPSquared]

I just ordered one from Bobby at BrewHardware but that thing looks like a serious piece of hardware. . .

 

[Brewing_on_the_Internet]

I found a post about a bottom drain electric brew kettle HawkATP had built. He used a strainer with the handle cut off on top of the outlet to filter the trub.

Link to post

Here are some pictures

 

[pogden]

I just ordered one from Bobby at BrewHardware but that thing looks like a serious piece of hardware. . .

Yeah, Bobby started iterating on his element enclosure shortly after I ordered mine. It looks sweet too. Looking forward to seeing how your build turns out.

 

[pogden]

I found a post about a bottom drain electric brew kettle HawkATP had built. He used a strainer with the handle cut off on top of the outlet to filter the trub.

Thanks for this. I'll definitely keep it in mind if I have difficulty with clogging. And I like the fact that it would make a hop sock/bag/spider unnecessary.

What would be really cool would be a stainless steel mesh cone or cylinder that fits into the drain ...

 

[pogden]

I couldn't find the cell phone picture of the wiring diagram I had on my whiteboard, so I whomped this up in Visio in case anyone's interested. A PDF version is attached as well.

I would not not have known where to start on this without all of the freely-shared knowledge from people on HBT. Thanks to P-J in particular, who's wiring diagrams made things very clear, and of course Kal, who started me thinking about going electric in the first place.

View attachment SSVR_eBIAB_Controller.pdf

 

[Bartman6969]

Is there any reason that the SSVR couldn't be wired inline with a traditional SSR output? My thinking is that after I am done mashing and want to boil I could just set A PID to like 250 and control the intensity of my boil with the SSVR Knob

 

[pogden]

Is there any reason that the SSVR couldn't be wired inline with a traditional SSR output? My thinking is that after I am done mashing and want to boil I could just set A PID to like 250 and control the intensity of my boil with the SSVR Knob

I have never thought of that, and I'm definitely not the right one to give an authoritative opinion. Assuming that the output of the SSR is really 240V when the PID is set to 250F, I suppose it might work. But think of this: SSRs generate a fair bit of heat, which has to come from somewhere. You would have to be drawing more power, or sending less that you expect downstream to the SSVR. And, I'm not sure how well an SSVR works if it doesn't see a relatively steady 240V on its input side,which it wouldn't if the PID was was set to maintain a temp below boiling or below 100% in manual mode.

What you could do is use a double pole selector to switch between a PID and a PWM controller as control inputs for an SSR. There's a P-J diagram around here somewhere for that, and a good thread or two on how to build a PWM controller.

 

[stlbeer]

Is there any reason that the SSVR couldn't be wired inline with a traditional SSR output? My thinking is that after I am done mashing and want to boil I could just set A PID to like 250 and control the intensity of my boil with the SSVR Knob

If you choose the correct PID, i.e. one with manual control, placing a SSVR w/ knob after it would be redundant.

There are many PIDs that support manual mode.

 

[KPSquared]

Lots of guys find it easier to turn a knob than fiddle with the PID controls to set manual mode. It's just easier. Nothing wrong with it.

 

[pogden]

One of the most important things to me was simplicity. PIDs are great, once tuned properly, at reaching and maintaining a setpoint. But I wanted to build a BIAB setup (simple), and wanted to avoid, if possible, having to re-apply heat once the kettle reached strike temperature. There were several reasons for this:

1. To avoid scorching the bag (yeah, I know - most people say it isn't a problem, but I wanted to avoid the possibility), and to avoid using additional apparatus like a steamer basket or element shield or prevent bag scorching (simple, easier cleanup, less crap to store)
2. To avoid needing to recirculate due to temperature stratification (simple).

By insulating the keggle with a KegSkin (and a big folded up towel on the lid), I hoped that the mash would not lose more than a degree or two. During a "wet run" I realized that the this was unlikely, but I found that by turning the element on very low (drawing ~1 to 2 amps) I was able to keep the temperature (of plain water, with no bag) relatively constant. I'll post separately a description of my first brew day, which had completely different results.

 

[KPSquared]

You can't base heat loss off a keggle full of water. . . There's just no comparison in thermal mass once you add several pounds of grain.

I plan to recirculate just for consistency in my beer but the ones I've done by just heating to temp and then leaving alone have had very low losses.

 

[jCOSbrew]

Nice simple eBIAB setup.

If you want PID control during mash you can use a relay output PID to turn the contactor ON/OFF as required. If the OP uses enough insulation he wont need to add heat or could simply remove the lid and stir while heating the mash a couple degrees every 20-30 minutes. My "insurance" against burning the bad is a sheet of silicon material over the element.

I use hop bags and everything else in the kettle goes through the pump and into the fermentor. Don't think you will have trouble with clogging if you filter most of the hops.

 

[pogden]

There are two aspects of my new rig that concerned me. First was maintaining a relatively constant mash temperature without heating/recirculating and without using a basket insert. Second was trub management. I've discussed both briefly in this thread, but if I'm being honest they are the two areas that seemed likely to cause me some trouble.

So, here's how things shook out on my first brew day.

Based on dry grain temperature of 72F and aiming for a mash temperature of 152F, I heated 8.5gal of strike water to 158F. I then killed the element, added the bag and doughed-in, stirring well. When I was satisfied that there were no more clumps, I put the lid on and only then glanced at the thermometer, which now read 144F!

I pulled the top of the bag down around the outside of the kettle (to raise the bottom of the bag inside). I then turned the element on about halfway (~11A) and stirred every few minutes while the temp came back up. Within 15 minutes, I was back at 152F. I left the element on very low (about 2.0A), and settled back to enjoy a Kiltlifter clone (thanks, Scottland) for the remainder of the 60-minute mash.

The temperature remained constant for the next 58 minutes or so. As I was rummaging around on the other side of the garage for a suitable container for my spent grains, the alarm on my thermometer (which was still set at 158F) went off. By the time I got back to the kettle it was in the mid 160's and climbing rapidly. WTF?

I killed the element, opened the lid, and everything looked okay. I removed the temperature probe (I'm using one of those remote oven/BBQ thermometers with a wired probe) gave it a quick stir, and then reinserted the probe ... 240F! Obviously a problem with the thermometer. I checked with my Thermapen and the temp was actually 150F.

As all of this nonsense occurred at the very end of my planned 60 minute mash, I raised the bag and took a refractometer reading (9.0 Brix, 1.036 SG). That seemed a bit low, and while I had not planned to do a mash out (in theory, it shouldn't be necessary), I thought maybe it would help me recover a bit more fermentable sugar.

So I turned the heat on high and stirred frequently until the temperature reached 170F, killed the heat and lowered the bag back in. I stirred a few times over the next 10 minutes. I then raised it again and let it drain while applying full heat for the boil. I squeezed the bag well. At this point, I measured 8 gal in the boil kettle at 10.6 Brix (1.043 SG), which made me feel a little better.

Fifteen minutes after applying full heat, boil started. I wanted to end up with around 5.5 gal of usable wort at the end of the boil: 5 gal or a bit more into the no-chill corny, plus a good liter for the yeast starter. That meant I needed to boil off about 2 gal during the 90 minute boil. During my "wet run" with plain water, I measured my boil-off rate at around 1 gal per hour, so I set the heat for a somewhat aggressive rolling boil (13.0A).

Everything went well during the boil. A total of 3oz of pellet hops were added in several additions, with a half-tab Whirlfloc 5 minutes before flameout. After killing the heat, I covered the kettle and let it stand for 15 minutes to settle.

I drained the first 8-12oz or so into a separate container to be discarded (this includes 5oz that was trapped in the bottom drain plumbing). I then fitted a piece of silicone tubing to the drain valve and started draining into a sanitized corny keg through a paint strainer. This went reasonably well, but slowly (about 45 minutes to drain 5 gal). When the corny was as full as I wanted (right to the top seam), I removed the tubing and strainer back to a sanitized 1 gallon container to collect the starter wort. Surprisingly, the bag was completely empty, which meant that the improvised stainless steel mesh strainer I had fashioned and inserted into the drain opening (in the bottom of the kettle) did its job well.

Too well, in fact ... by this time, the flow from the kettle was basically stopped. I reached into the bottom of the kettle with a sanitized rubber glove and dislodged the filter screen. I was then able to easily drain the kettle completely, and collected a good liter and a half of starter wort (and ball of hop and break material the size of a nerf football in the strainer bag).

I let the starter wort settle a bit more while I cleaned up, then poured off the top liter into my starter flask. When it reached 75F, I pitched a vial of WLP001 and let it stir overnight.

Start to finish, I little over 4.5 hours. Lessons learned, and things to do differently:

• As the strike water reaches the target temperature, I'll give it a good stir, which I neglected to do this time. It will be interesting to see of the temperature swings a lot, or if it's relatively uniform due to convection.
• Depending on the results of the previous step, I may add an extra 1-2F to my strike temp.
• Take care to keep my thermometer probe from being submerged in wort beyond the end of its shroud. I'm pretty sure this is what caused the thing to go nuts at the end of the mash.
• Get a better thermometer, and maybe add a long thermowell to my kettle lid.
• Consider a much shorter mash period (like, 20-30 minutes, or even less). I've read several posts lately that seem to indicate that conversion is essentially complete after the first 10 minutes or so. This could be huge as it would greatly help with my goal of not messing with heat during the mash.
• Learn about, and get whatever is needed to do an iodine test (to determine whether conversion is complete).
• Determine my refractometer's "Wort Correction Factor" according to the procedure recommended by Brewer's Friend.
• Rethink my approach to trub management. My little trub screen worked okay, but definitely got plugged up at the end. I think I'll try HawkATP's inverted kitchen strainer idea first as I like the idea of letting the hops float free in the boil. If that doesn't work well enough, I'll try adding the hops to a paint strainer. I really need to keep as much of the hops/trub/spooge as I can out of the fermenter (a slim quarter Sanke), but that's another post.
• Consider collecting the starter wort first so that it can start cooling and be ready for pitching sooner.

Just for completeness, here are a couple of pics of my rather inadequate attempt at fabricating a trub filter out of some 30-mesh stainless fabric. It's surprising sturdy and very simple, but ... didn't work as well as it needed to.

 

[KPSquared]

Why not use your trub screen but increase to a size more like a Hop Stopper. Just a bottom drain instead of a dip tube version. That is currently my plan. 6 or 8 inches across with something to tie it into the bottom drain. Should work well with the increase in surface area?

In regards to starters, I have a friend that does a basic 2 row mash, then just puts everything in jars and cans the wort. Then he has sanitary starter for his whole brew season.

Maybe just make a DME starter the day before and save some time?

 

[pogden]

You can't base heat loss off a keggle full of water. . . There's just no comparison in thermal mass once you add several pounds of grain.

That makes sense, but I wanted *some* idea of what the heat loss might be. Would you expect the thermal mass of 8.5 gal of water + 1.5 lbs of grain to be greater or less than 8.5 gal of plain water? Without putting any thought (or research) into it, I assumed that the thermal mass of the water+grain would be greater (or at least similar) and therefore no more difficult to keep stable, but maybe I need to revisit high school chemistry and thermodynamics.

 

[pogden]

Why not use your trub screen but increase to a size more like a Hop Stopper. Just a bottom drain instead of a dip tube version. That is currently my plan. 6 or 8 inches across with something to tie it into the bottom drain. Should work well with the increase in surface area?

In regards to starters, I have a friend that does a basic 2 row mash, then just puts everything in jars and cans the wort. Then he has sanitary starter for his whole brew season.

Maybe just make a DME starter the day before and save some time?

I've thought of a hop-stopper-shaped thing, but the right way to fit it to the bottom drain hasn't revealed itself to me yet. I guess I could make a square pillow-shaped thing out of one or two pieces of mesh seamed together. The bottom side would have a ~2" OD tube of some sort (ideally, stainless) somehow punched through and then soldered/clamped into place. The thing is, the 30-mesh SS fabric isn't very flexible/stretchable. I suppose the thing to try would be to cut the hole smaller than 2", then "dimple" it by pushing through some sort of cone-shaped thing until it expands to the right diameter. Heck, it might even be possible to just use the dimpled/extruded lip of the hole as the attachment - just insert it into the drain opening. Hmmm ...

Regarding starters, I've made canned wort before. It works great - in fact, I recently used up the last of a batch I made TEN YEARS ago, and it worked fine. But there's an appealing symmetry to using the same wort that I'm going to be fermenting as the starter wort.

 

[KPSquared]

I was thinking the dimple thing and then silver solder. Maybe use the keg spear somehow?

 

[Bartman6969]

If you choose the correct PID, i.e. one with manual control, placing a SSVR w/ knob after it would be redundant.

There are many PIDs that support manual mode.

I understand how a manual mode on a PID works. I just like the idea of a knob as opposed to buttons. To each their own