HOWTO - Make a BrewPi Fermentation Controller For Cheap

[day_trippr]

And he could just have the relay side wired backwards

I agree.

Cheers!

 

[aubiecat]

And they have plenty of room for 2 jacketed cables meaning I can cut down on the amount of connectors needed to finish out my project.

Right on! That is good news.

 

[balrog]

While we're talking about probe placement, has there been any discussion on the best place to place a thermowell with respect to the sidewalls of the fermenter? If you had a thermowell in the fermenter, but up against the wall, it would be similar to having a probe insulated to the outside of the fermenter. In contrast, you could put the thermowell dead center. This would result in longer cycle times (probably). Which would provide the best approximation of the overall beer temperature? I'm sure this has been studied by someone at some point, whether they were brewers or chemists doing something totally different, but I'm not familiar with any actual studies. It seems to me that about about 1/4 to 1/3 of the diameter of the fermenter from the wall would be better than either dead center or up against the wall, but that is a total guess!

I've wondered about all these points as well. And whether you use plastic or glass, the latter which transfers ambient to a side mounted probe faster than plastic. And how long thermal equilibrium takes between center-mass and side wall, whether during exothermic part of fermentation or afterwards.

So, to someone's good point earlier, something is better than nothing. That's got to be the first order correction to the situation. Then second order or higher terms will be probe placement (and perhaps multiple probes to average the center-mass temp, mid-side-temp, side-temp, or more).

Clearly, we're going to have to make a full vessel internal radiator with constant recirculating coolant so that the fermenting mass is temp controlled throughout its mass at all times. And with that, it's really no longer much fun.

 

[wbarber69]

Going down for the crash this weekend

 

[balrog]

So crashing is 7 degrees per day? I thought it would be faster.

 

[mmmooretx]

Going down for the crash this weekend

View attachment 231304

Looks good, I get more cycles but the beer temp is stable to 0.2-0.3F even on the crashes, but I am only doing 2F a day on my water run. I am cutting it off this Sat. on my right unit to do a lager, Urquel clone run, 10 gallon batch. This will be my first wort/beer run on the BrewPi but my water test runs on both units is rock solid. I would be interested if you tailored the cycle items in the config settings, if so what did you set them to?
Thanks
Mike

Update: Did a 48 hour sample so scales are similar.

 

[day_trippr]

So crashing is 7 degrees per day? I thought it would be faster.

Seriously. That's more like a "slump" than a "crash"

I drop 10 gallons of beer from post-fermentation-clean-up ~68°F to 34°F in well under 48 hours - as fast as the fridge can manage it...

Cheers!

 

[FuzzeWuzze]

Looks good, I get more cycles but the beer temp is stable to 0.2-0.3F even on the crashes, but I am only doing 2F a day on my water run. I am cutting it off this Sat. on my right unit to do a lager, Urquel clone run, 10 gallon batch. This will be my first wort/beer run on the BrewPi but my water test runs on both units is rock solid. I would be interested if you tailored the cycle items in the config settings, if so what did you set them to?
Thanks
Mike

Update: Did a 48 hour sample so scales are similar.

The BrewPi has a control constant variable in the advanced setting area called PID Maximum. This is basically the largest the delta between the beer temp(not the set temp) and the fridge will ever be and its 18F by default. So you cant "crash" a beer as hard because if your beers at 68 and you set it to 35, it will only take the fridge down to 50. Then when the beer hits 67 it will set the fridge to 49, etc until it reaches your 35F. This is good because it prevents a lot of overshoot, but it also slow down cooling.

Try setting it to your set point-5F when you really need to chill something fast. So if you want it to be 35F, set the PID Max to 30F. This will allow your beer to chill much faster, i use this when i put my wort in after chilling down to 80F.

Just make sure to tighten it up when you are not crashing your beer, to either 18F or to something even tighter. I usually keep mine at 10F, this just further prevents the fridge from overshooting.

 

[wbarber69]

I haven't changed anything in the settings other than from c to f. This was a batch I made to test a piece of equipment for something else I have going on. Crash or slump. Basically I already ran the fermentation. Since it was an ale I just ran it at 68 for a week till I noticed brewpi had to start working to keep it warm. I've been busy so I dont have time to take samples inbetween working and passing out. So instead of doing a rapid crash over 2 days. I brought her up to 72 to clean up then just let it ramp for the rest of the week till Sunday when intend to transfer to keg. That way if there were still a few stubborn yeasties they'd have time to do what they needed before going to sleep. This batch had a pound of honey in it so it started out around 1.065 and it should have finished quick anyway.

 

[balrog]

No offense intended, just wanted to know whether I should be taking beer cold prior to bottling at a slower rate for some reason. My poor little dorm fridge cube can't do better anyway; that is, no better than 16°F/day, from 70°, current ambient basement temps.

 

[Dunesailor]

Hmm, is this only for switching a door light, or will you also control the compressor with that? It can only switch a max of 2A. Probably okay for a couple of Fermwraps though.

SON OF A ****** I didn't notice that! Arrrgh, back to the drawing board.

 

[craigmw]

SON OF A ****** I didn't notice that! Arrrgh, back to the drawing board.

Yeah, sorry to point that out. I just didn't want you burning something up. I'm not really sure how an overloaded SSR responds. I know that the typical SSR failure mode is to keep the circuit on, which would likely lead to overheating, so this could be dangerous. Also, SSRs running near their max current rating produce plenty of heat, and those SSR boards don't have a provision for easily adding heat sinks. It's probably best to just stick with the standard 2 (or 4) relay boards. They will eventually fail from repeated cycling, but I think I'll probably get a year or two out of mine based on the published specs for the relays.

 

[Dunesailor]

Ya I'm just going to stick with the SainSmart but add transistors to reverse the output so the LEDs work they way I want.

 

[wbarber69]

Ya I'm just going to stick with the SainSmart but add transistors to reverse the output so the LEDs work they way I want.

You shouldn't have to do that. You may just have the relay output set to normally closed. You'd just have to use the normally open side. Basically the relay is a single pole double throw switch. One side will pass current through when the relay is deactivated. The other side will be off until the relay is activated. Everyone else is using the same relay you are you just don't have it hooked up rights

 

[wbarber69]

Ya I'm just going to stick with the SainSmart but add transistors to reverse the output so the LEDs work they way I want.

You shouldn't have to do that. You may just have the relay output set to normally closed. You'd just have to use the normally open side. Basically the relay is a single pole double throw switch. One side will pass current through when the relay is deactivated. The other side will be off until the relay is activated. Everyone else is using the same relay you are you just don't have it hooked up rights

 

[Dunesailor]

I don't see how I have it hooked up wrong. Are you saying that at idle the LEDs on the relay board should be lit?

 

[wbarber69]

At idle they should be off. If they are lit then change the inverted state. If whatever is hooked up up to the relay is on when light is off then you have the relay side hooked up backwards.

 

[FuzzeWuzze]

Yeah, sorry to point that out. I just didn't want you burning something up. I'm not really sure how an overloaded SSR responds. I know that the typical SSR failure mode is to keep the circuit on, which would likely lead to overheating, so this could be dangerous. Also, SSRs running near their max current rating produce plenty of heat, and those SSR boards don't have a provision for easily adding heat sinks. It's probably best to just stick with the standard 2 (or 4) relay boards. They will eventually fail from repeated cycling, but I think I'll probably get a year or two out of mine based on the published specs for the relays.

Ive read more than a few threads on people with electric systems having SSR's smoke and flame from failing, i wouldnt even think about running a SSR even at its recommended range..i'd always want some buffer.

 

[wbarber69]

I've gone through 4 in my brewery panel and it's less than a year old

 

[day_trippr]

It's alive!

Cheers!

 

[wbarber69]

Show off…

 

[aubiecat]

It's alive!

Cheers!

Very sharp. Nice work man, now brew some damn beer!

 

[kevink]

Sick! I love it! That would look right at home on my stereo rack!

 

[day_trippr]

Very sharp. Nice work man, now brew some damn beer!

Thanks! I've been staying off the streets (and keeping really late hours) with this little project

fwiw, my pipeline is actually doing nicely - the keezer has six near-full kegs, two more in the carb fridge, and my ferm fridge is filled with carboys from last weekend that have another week and a half before they're kegged. Next brew day for me is looking like 11/08, so I have that much time to get this fitted into my keezer.

It's all good!

Cheers!

 

[wbarber69]

One of the things holding back my progress is my pipeline. Not so much anymore. But we had an unbearably hot summer. And I got my second hand fridge around that same time. So it's been either empty and under modification or in use, project on hold. I don't think I'd have the discipline or patience to create something that good looking either.

 

[FuzzeWuzze]

Ya too many are cheap Chinese stuff that's not really high quality.

 

[atoughram]

I'm doing a Brewpi remodel...

I might add the encoder next... Who knows..

 

[Dunesailor]

what type of shield is that on your Arduino?

 

[atoughram]

what type of shield is that on your Arduino?

Seeduino Proto Sheild that is custom wired.

 

[wbarber69]

Seeduino Proto Sheild that is custom wired.

What is the reed relay for?

 

[atoughram]

What is the reed relay for?

I think your seeing a 10K 10 turn pot for contrast adjustment

 

[gromitdj]

In case anyone else is still interested, I ran a test to compare the probe placement during control of my Fermentation Chamber.

To do this I started with my Beer Temp probe placed in a 12" Thermowell in my 3 gallon Better Bottle filled with water. The Room Temp probe was placed on the Side of the Fermenter under a Microfiber cloth held in place with a large rubber band. For the initial test, I purposely did not want to efficiently insulate the probe from the Fridge Temp.

I ramped the temperature to 60°F and maintained that temperature for 4 consecutive days. Below is a snippet from the first day following the ramp to 60°.

The following evening, I switched the locations of the Beer Temp and Room Temp probes. In the following image, the Room Temp is now showing the Thermowell temperature.

It appears that the Thermowell Temperature remains pretty constant, but the compressor cycles more frequently. Also, the BrewPi uses the heater to maintain temps in this configuration. I do not have a heater installed currently, but my ambient temps rarely go below 60°.

Following that, I provided additional insulation to the probe to see how that would effect the control. It is surprisingly close to the same control as the thermowell.

Hopefully this is insightful to someone other than myself.

 

[atoughram]

Here was my last fermentation run - well within half a degree. Thermowell in a 17 gal. plastic conical.

 

[wbarber69]

My most recent fermentation.



Using a thermowell for beer temp. And fridge temp tucked under the ferm wrap.

 

[alfista]

Help - I've been having some problems, and just did a full rebuild.

Before I did so, my situation was that I was hoping to warm up a pils for a diacetyl rest, but the fridge was constantly running despite saying it was heating. I did not have a heating element attached. I confirmed that both heating and cooling outlets were simultaneously trying to fire. Everything was working fine (more or less) until this.

So, I rebuilt everything and re-flashed the Uno (saving sensor mappings) and the system is set to be 'off' while I let it warm up. However, the fridge was still running if I plugged it in to the switched outlet.

As mentioned, everything was running fine. Not sure what is going on here. I don't think I have any shorted wires as it was pretty well insulated and installed where it could not be disturbed.

Any thoughts?

 

[wbarber69]

Relay board or ssr?

 

[jspain3]

Hope I have this wired up correctly.

 

[day_trippr]

[...]
Before I did so, my situation was that I was hoping to warm up a pils for a diacetyl rest, but the fridge was constantly running despite saying it was heating. I did not have a heating element attached. I confirmed that both heating and cooling outlets were simultaneously trying to fire.[...]

I don't understand that last part. It reads like it was expected behavior - but I'm pretty sure it isn't at all normal for BrewPi.

If you used a duplex outlet for your two switched outlets, did you remove the hot-side bridge?

Cheers!

 

[FuzzeWuzze]

I don't understand that last part. It reads like it was expected behavior - but I'm pretty sure it isn't at all normal for BrewPi.

If you used a duplex outlet for your two switched outlets, did you remove the hot-side bridge?

Cheers!

Thats my guess as well, so both his hot and cold are getting power at the same time he just never knew it because he probably never had anything on the heater.

 

[alfista]

I don't understand that last part. It reads like it was expected behavior - but I'm pretty sure it isn't at all normal for BrewPi.

If you used a duplex outlet for your two switched outlets, did you remove the hot-side bridge?

Cheers!

Thanks Day and Fuzze - something weird is going on. I definitely have the hot side bridge removed. I had tested it when I built it and was able to control each independently. In doing some troubleshooting this morning, I power-cycled everything and upon boot only the cold outlet powered on and not the hot. BrewPi says it is idling, but it is still trying to cool, even when BrewPi is set to off. My first two fermentations did almost exactly what I wanted them to do, even without having implemented a heating element. Is it possible my Arduino board went bad or a relay is stuck?