Brewpi Fermenting Fridge

[tim_n]

Just got myself a cheap RL6003A Frigidaire fridge from eBay

Ordered a brewpi shield from Norway

Thermowell from the US

SSR, LCD & Arduino from China

Sensors from Lowestoft

Made a case for it all at the London Hackspace.

Total cost so far has been about £160.

It'll eventually make a controllable fermenting space which is in the garage, rather than in the house. SWIMBO doesn't like the fermenter in the house (it goes where the washing dries) and I agree as it's in the spare room and occasionally I need to sleep there (non brewing or SWIMBO related, honest) and the bubbling keeps me awake.

 

[coyspurs]

Tad expensive?

 

[Maysie]

I think my STC version was around £45, (with a free fridge).

STC: £12
Heater: £15
Sockets and cables: £6
Grommets: £3
Project box: £6
Fridge: £free
Wood for shelf: £3

I like the geeky idea of having the Pi thing though... :ugeek:

 

[hairybiker]

Mine was much the same, fridge FREE - our old main (larder type) fridge on which the thermostat failed. (Replacement fridge/freezer from Freecycle :thumb: )
STC 1000/case/grommets/2m of 4way mains cable ~ £30 (4way made for easy install L*2/N/E)
1ft tublar heater ~ £14 from ebay.

I had some spare wood from an old bed, cut to size for the fridge to hold the FV/beersphere on.

If it had been >£50 it just wouldn't have been done, but having most of the parts ... :hat:

 

[tim_n]

All good points however personal circumstances really do require the pi. I currently have a 6hr commute or a night in a hotel. They're the same cost to the business, so I generally stay for most of the week. I can't guarantee I'll be home to deal with the brew when I'm away and it can be 6 days before I can do anything temperature wise. Generally when I've made beer, it sits in the guest bedroom and it ferments about 18-20'C. Which is generally fine for the beers I'd been doing in kits. Now I'm venturing into the world of german wheat beers and I want to have a go at some lagers, I need more control. The most expensive bit is the raspberry pi (which I already owned for a previous project), the shield and the fridge.

£49 Shield
£14 SSRs
£5 Sensors
£25 Fridge
£8 Arduino
£30 Pi
£3 Box
£15 Thermowell
£5 Wire
£2 Grommets
£6 LCD

At least I'll be able to access it and control it in Swindon :)

 

[Maysie]

At least I'll be able to access it and control it in Swindon :)

Now that's cool!

 

[mojonojo]

My first brew in by brewpi fridge

 

[tim_n]

My first brew in by brewpi fridge

Good stuff - are you using a thermowell or is the rapid oscillation of the cold/hot trying to balance the beer temp a little too much? I know fermenting raises the temperature, but I wouldn't expect to see both on and off so much.

I like how the cold crash works :)

 

[mojonojo]

My first brew in by brewpi fridge

Good stuff - are you using a thermowell or is the rapid oscillation of the cold/hot trying to balance the beer temp a little too much? I know fermenting raises the temperature, but I wouldn't expect to see both on and off so much.

I like how the cold crash works :)

the oscillation is the correction of temperature around the set temperature - first part of the graph has a 1c swing on temperature before i realised i had the fridge set on its highest temp setting (1) rather than its lowest temperature setting (5) so the temperature response after the cold crash. - (you may also be looking at the 'fridge temp' rather than beer temp - which is the green line)

the control of beer temp is pretty accurate within .05c of the set temperature - see below -

 

[The Goatreich]

OMG, that kind of setup is going as part of my wish list when I finally upgrade to a fully stainless, fully temp controlled setup.

 

[djcorbetto]

I have a brew pi somewhere. Never really did anything with it as I didn't know what I was doing just wanted someone to sort it out for me.

 

[tim_n]

the oscillation is the correction of temperature around the set temperature - first part of the graph has a 1c swing on temperature before i realised i had the fridge set on its highest temp setting (1) rather than its lowest temperature setting (5) so the temperature response after the cold crash. - (you may also be looking at the 'fridge temp' rather than beer temp - which is the green line)

the control of beer temp is pretty accurate within .05c of the set temperature - see below -

I think the confusing bit was the view over 10 days, just surprised so much heating/cooling was going on as it seemed to be cooling/heating by about 5'C even though the beer temp was so static.

Do you use a thermowell mounted in the beer for the beer temp? From what I understand if you get a good average temp in the beer using a nice long thermowell, the amount of time your fridge does heating/cooling is greately reduced. Just makes for a lower electricity bill I guess and cleaner graphs.

 

[seanmac]

So am I right in saying that the orange fridge setting is the temp you want the fridge to be? and that is causing the oscilaltion?

That oscillation looks pretty crazy, about 20 oscillations a day? with an amplitude of 5oC? PID should be alot more stable than that. If this is not what your after, have you tuned the system at all? Looks like it is near the ultimate gain and period which you could then put in Ziegler-Nichols and get the correct constants?

Maybe im just mis-understanding though cause your latest graph of beer temp looks good!!!

 

[mojonojo]

So am I right in saying that the orange fridge setting is the temp you want the fridge to be? and that is causing the oscilaltion?

That oscillation looks pretty crazy, about 20 oscillations a day? with an amplitude of 5oC? PID should be alot more stable than that. If this is not what your after, have you tuned the system at all? Looks like it is near the ultimate gain and period which you could then put in Ziegler-Nichols and get the correct constants?

Maybe im just mis-understanding though cause your latest graph of beer temp looks good!!!

no the orange line is incidental to the process, the green line beer temp is what im controlling.

its set to stable beer temp (19.5c, 21c and then 2c) so the beer stays stable (within 0.05c) and the environment (heating and cooling) changes to keep the beer stable.

im just setting the system up at the moment, literally the first batch through it, so its still learning the setup

 

[tim_n]

So am I right in saying that the orange fridge setting is the temp you want the fridge to be? and that is causing the oscilaltion?

That oscillation looks pretty crazy, about 20 oscillations a day? with an amplitude of 5oC? PID should be alot more stable than that. If this is not what your after, have you tuned the system at all? Looks like it is near the ultimate gain and period which you could then put in Ziegler-Nichols and get the correct constants?

Maybe im just mis-understanding though cause your latest graph of beer temp looks good!!!

no the orange line is incidental to the process, the green line beer temp is what im controlling.

its set to stable beer temp (19.5c, 21c and then 2c) so the beer stays stable (within 0.05c) and the environment (heating and cooling) changes to keep the beer stable.

im just setting the system up at the moment, literally the first batch through it, so its still learning the setup

Are you using a thermowell (a long bit of steel mounted in the beer)

 

[The Goatreich]

Yes he is, according to post #1.

 

[tim_n]

Yes he is, according to post #1.

You mean my post???

 

[The Goatreich]

Ha, apologies. I thought somebody was asking you if you were using a thermowell.

 

[tim_n]

I've asked a few times, just interested because I've ordered one to make the temperature measuring more stable and may explain why the fridge is cooling & heating so much and if he is where he got it as I'm having to ship one from the US!

 

[bobsbeer]

Southern Temperature Sensors have thermowells in various lengths and are in the UK. This one is 250mm

HERE