What would the best temperature controller do?

[red_car]

Hi all

I'm fairly new to home brewing. A friend and I have recently put together what we think is a pretty nice gravity fed all grain brewing setup.

My other hobby is building electronic devices... including the temperature controller that we use to maintain ideal fermentation conditions. The device I built first our first couple of brews includes both heating (heat pad under the fermenter) and cooling (unmodified fridge) control.

The unit also includes an SD card to log data so I could monitor Target, Current, and Ambient temperatures... pretty good results... managed to control within .5 degrees C of the target which I was pretty happy with.

For lager brew... I've improved the unit to automatically cool from primary fermentation temperature over a week to a set lower value. Automatically... 19 C for 1 week, cool from 19 C -> 4 C over 1 week, then constant at 4 C.

My question.... if you could imagine a temperature controller that gave you all the features you could imagine.. what would they be? I'm keen to built it !

 

[Pkrd]

Probably something like these... the first reflashes the cheap STC1000 for an all round better fermenting experience, and the second adds a lot of bells and whistles.
https://www.homebrewtalk.com/showthread.php?t=464348
http://www.brewpi.com

Welcome to HBT

 

[Bellybuster]

I would for sure add Bluetooth/wifi connection and an easy to use app.
I have the STC1000+ and will probably never use its functions due to it being a pain in the ass to program.
I would also keep the price under $100. Over that point and you limit your sales by 80%. (A guess)

 

[RM-MN]

Most beers will benefit from controlling the temperature to keep them cool during the initial fermentation, then raise the temperature slowly for a few days to allow cleanup/diacetyl rest, then lower the temperature to take the yeast out of suspension. There will be a few differences in timing and the amount of temperature change for lagers and ales.

 

[gezzanet]

Build a brewpi. They are excellent. View attachment ImageUploadedByHome Brew1443611834.410270.jpg

 

[kombat]

For lager brew... I've improved the unit to automatically cool from primary fermentation temperature over a week to a set lower value. Automatically... 19 C for 1 week, cool from 19 C -> 4 C over 1 week, then constant at 4 C (sorry about the degrees C.. i'm in New Zealand)

I have no input on your device design, but I would strongly encourage you to read up on lager brewing. That temperature schedule is nowhere close to correct. 19° C for the first week is waaaay too hot for a lager (heck, I ferment my ales at 18° C for the first week). That should be much closer to something like 10° C, for the first two weeks (not one), then let it warm up to room temperature (20 - 22° C) for 3-4 days (the diacetyl rest), then slowly cool it down to 4° C over a period of several days to lager it for a few weeks.

 

[AnOldUR]

Just like new brewers are told to not use a time table to determine when to bottle or transfer beer, because yeast are living things that don't always play by your rules. I think the same holds true here, and especially with ales. I prefer to use visual clues to determine when it's the right time to start ramping up the temperature and how much to ramp it. Can you force the process with a programmable controller? Sure. Will that produce the best product? I don't know.

If I were brewing the exact same grist, with the exact same yeast, at the exact same cell count every time, a programmable controls might be great. On a homebrew level with no lab or product line, for me it would be an over use of technology. I prefer a manual control.

 

[gezzanet]

+1 visual clues. I wait for main fermentation phase to be over then ramp a couple of deg for ale over 2 days after that. You can can he the profile to what you want when you want. At some stage there will be a gravity meter to set ramp times automagically. Crystal ball gazing[emoji33]

 

[robbyice1]

I would give one of my plums for a temp controller that I could adjust remotely from my smartphone from anywhere on the planet. (at work)

 

[Bellybuster]

I would give one of my plums for a temp controller that I could adjust remotely from my smartphone from anywhere on the planet. (at work)

Yes Sir!!!!


as far as time tables and visual clues and not wanting auto control, far from what the OP is even remotely asking.
I use an STC1000+ and program ferment scenarios beforehand. If you know your yeast and know your process you can predict fermentation times quite well. Add a bit of fudge factor and Bob's your uncle. Stuck or slow ferments are seldom if ever due to the ferment chamber.

BrewPi looks awesome but needs a bit of know how and has to be built, the price adds up very quickly with it too. A sub $100 remotely accessible programable controller would be the cats azz. Wish I had the brains to do it.

 

[red_car]

Hi all

Thanks for all the feedback and advice....

I'm going to start work on a new device... Here's my current one btw... http://i62.tinypic.com/10ntk46.jpg


I'll build something that can a have multiple temperature periods... And a period can either be a constant temperature, or increasing/decreasing over time. Will make it so that you can save a set of these for a given brew type.

I'll make it wifi enabled so it can be controlled from a smartphone... In theory from anywhere.

I reckon it'll take me about a month for a prototype version... Watch this space !!

 

[gezzanet]

You might want to look at the how to make a brewpi for cheap on this site. All the things you mention have been covered so far. Maybe a good starter. Also you might be able to make some of it better[emoji12][emoji12]

 

[Gavin C]

I have no input on your device design, but I would strongly encourage you to read up on lager brewing. That temperature schedule is nowhere close to correct. 19° C for the first week is waaaay too hot for a lager (heck, I ferment my ales at 18° C for the first week). That should be much closer to something like 10° C, for the first two weeks (not one), then let it warm up to room temperature (20 - 22° C) for 3-4 days (the diacetyl rest), then slowly cool it down to 4° C over a period of several days to lager it for a few weeks.

Absolutely. Lagers are fun to make and rendered very doable with precise temperature control. Not exactly the profile I use but pretty darn close. Lagers ferment cold. ~9 to 10C (I pitch at 9, ferment at 10)

Most recent lager's ferment schedule

Just like new brewers are told to not use a time table to determine when to bottle or transfer beer, because yeast are living things that don't always play by your rules. I think the same holds true here, and especially with ales. I prefer to use visual clues to determine when it's the right time to start ramping up the temperature and how much to ramp it. Can you force the process with a programmable controller? Sure. Will that produce the best product? I don't know.

If I were brewing the exact same grist, with the exact same yeast, at the exact same cell count every time, a programmable controls might be great. On a homebrew level with no lab or product line, for me it would be an over use of technology. I prefer a manual control.

Agreed

I'm all for brew gadgets and using technology to our benefit but I've yet to see the compelling need for a BrewPi. I make three temperature adjustments during fermentation for lagers.

1. After pitching adjust temp from 9C to 10C and allow a passive rise

2. Once I've determined the gravity is 1-2 plato above projected FG I change the temp to 67F and allow a passive rise. This usually takes two days.

3. Once I've determined Fg has been reached I set the temp to ~0C and crash cool it.

That's it. I've yet to read a compelling argument for wifi constant monitoring of the temperature. All the adjustments are within a two week span and each takes 5 seconds to carry out using an STC1000.

For me, visual clues and subsequent confirmatory gravity readings dictate when changes are made to the temperature.

I do like the brew Pi idea though and am not disputing the benefits of precise temperature control. I'm sure there is a ton of fun to be had making one.

 

[alphaomega]

Pitch enough healthy yeast at the apropriate temperature and you are half way there.
Thermostat control is fine, even just keeping the temperature in check with ice packs / frozen bottles works fine for a lot of people.
Beyond that, the 'best' controller is in the eye of the be(er)holder. If you desire logging, wifi or whatever, that is cool and all and completely up to your own requirements, but you quickly reach a point of diminishing returns, where it will not do much for the resulting beer.
Imho, first and foremost, you need to design your controller to be reliable and failsafe. Make the required features robust, then add the nice to haves.

Cheers!

 

[alphaomega]

I have the STC1000+ and will probably never use its functions due to it being a pain in the ass to program.

Sorry for an off topic post, but I feel like I want to answer this.
Yes, it is a bit tricky to program, but the STC is repurposed to do more than initially intended and I do feel like I have done the best I could given what I had to work with.
To mitigate this, there is the profile editor / sketch generator, which makes it a bit easier to visualize the profiles.
You have 6 profiles, and once you have those (or some of those) setup to your liking, you really don't need to fiddle much with programming it.

Cheers!

 

[Bellybuster]

I actually did program in a couple profiles and ave one running right now. Thanks for all your work in this.

Folks, the compelling argument for the OP's project is because he wants to. Fair enough

To the OP, go for it. For every nay sayer there's as many folks that would love to see this

 

[Gavin C]

I actually did program in a couple profiles and ave one running right now. Thanks for all your work in this.

Folks, the compelling argument for the OP's project is because he wants to. Fair enough

To the OP, go for it. For every nay sayer there's as many folks that would love to see this

Despite my feelings that I personally don't feel the need for one, I entirely agree with you here. Probably if I got one it would be like a smart phone. I'd wonder how i ever survived without it.

Definitely fun to make and see in action.

 

[red_car]

You're spot on... Making it is the fun part... Just like making beer really !!

 

[eric19312]

How about integrating the temp controller with a brew bug? Automate the temp increase at preset gravity... This would have benefit of not missing the window to get the diactyl rest in.

 

[gezzanet]

you're spot on... Making it is the fun part... Just like making beer really !!

+1

 

[Bellybuster]

How about integrating the temp controller with a brew bug? Automate the temp increase at preset gravity... This would have benefit of not missing the window to get the diactyl rest in.

That sure would be cool but certainly would toss affordability out the window

 

[alphaomega]

Continuously measuring SG is problematic to say the least.
I don't know much about the beer bug, even if it works flawlessly, it sure isn't cheap.
I've said this before, but I'll say it again, adding a simple IR gate (photo gate) to the airlock is a simple and cheap solution (bubble counter).
Lots of people here will tell you that airlock activity is not an indication of fermentation and that lack of airlock activity does not indicate lack of fermentation. While they have a valid point, the fact remains that active fermentation does produce vast amounts of CO2.
If you do have a leak free airlock, the rate of bubbling will be correlated in some way to the rate of fermentation. This can definately be used to determine when fermentation is slowing down and it is time to ramp up for diacetyl rest.
You'd probably need to do some test batches, preferrably with different yeast strains, while logging the result and measuring SG occasionally.
I'm pretty sure you could find some correlation in the data that would be useful this way (like when bubbles/hour is less than 50% of peak activity or something like that).
Still, even with this you probably should have some failsafes in place, like don't start diacetyl ramp up earlier than x days from pitch or later than y days.

Cheers!

 

[eric19312]

That sure would be cool but certainly would toss affordability out the window

Found this statement from the Beerbug guys on Reddit...

"ADDITIONALLY, you'll be happy to see our next product -- the BeerBug Temperature Controller. It speaks with the BeerBug and controls your temp (2 stage) based on the gravity and temp from your BeerBug.
For starters... can you say "perfect diacetyl rest"?"