# "Smart" fermentation controller idea

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#### mattd2

##### Well-Known Member
This thought just came to me last night but I wanted to get the collective Homebrew Talk wisdom on it first...
I have always wanted to have better control over my set points during fermentation, but also I'm also a bit too lazy to keep checking on activity throughout fermentation - the (potential) game changer... we can work out roughly how much heat energy should be released during fermentation (calculated from the amount of sugar and how much heat yeast produce per frame of sugar converted to alcohol and CO2) and we can measure how much heat a freezer/fridge is removing from the space from how much it is on (and a bit more maths, plus factoring in any losses to the general atmosphere), so by comparing how much energy has been remove by the fridge with the total expected to be remove we could estimate roughly how far through fermentation we are at... I think

So the question - do you guys see any big hurdles I haven't seen or assumption that don't make sense? Just so I don't waste a whole lot of time... but I do have 3 more weeks at least to fill so I will probably dig out some of my old Arduino gear to see what I have and how far I can take it...

#### Pkrd

##### Supporting Member
HBT Supporter
What you're talking about is Calorimetry, which is full of big equations, and is hard. Heaps of variables. A really really well insulated chamber with glycol chiller might be a better solution. Pumped this much glycol at this temperature in and this temperature out. Put in this many watts of electricity.

Definitely will fill in your three weeks, plus whatever Jacinda tacks onto the end.

OP

#### mattd2

##### Well-Known Member
Yeah you're right about the calorimetry, the only difference really is instead of trying to determine how much energy has been use down to the watt (or milli/micro/etc. -watt) it is way more rougher than that with measuring to the "yeah it's probably about time to bump it up a few degrees for a D-rest..."

And yeah if the Government decide more lockdown is need I have got my supplies to start providing essential services if the beer starts to dry up!

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OP

#### mattd2

##### Well-Known Member
This is has already been put to use to measure fermentation progress and does so very economically

https://www.mybrewbot.com/blank-page-1
Thanks HH - although what I was thinking was to just to make a (calculated) assumption about the energy transferred while the fridge/freezer is switched on rather than calculate the heat transfer from the fermenter compared against a reference temp. And have the controller control the ramping up/down of the set point rather than just being more obvious / easier to check manually.
Unless I have completely misunderstood how mybrewbot works?

#### _HH_

##### Well-Known Member
Thanks HH - although what I was thinking was to just to make a (calculated) assumption about the energy transferred while the fridge/freezer is switched on rather than calculate the heat transfer from the fermenter compared against a reference temp. And have the controller control the ramping up/down of the set point rather than just being more obvious / easier to check manually.
Unless I have completely misunderstood how mybrewbot works?
That sounds similar to my understanding - it can be used to remotely alter fermentation temps as well which is what got me interested in it

OP

#### mattd2

##### Well-Known Member
That sounds similar to my understanding - it can be used to remotely alter fermentation temps as well which is what got me interested in it
Yeah I should have mentioned that the "regular checking" would be much easier with the MyBrewBot as I wouldn't have to walk through the garage to get to check!

#### pocketmon

##### Well-Known Member
This thought just came to me last night but I wanted to get the collective Homebrew Talk wisdom on it first...
I have always wanted to have better control over my set points during fermentation, but also I'm also a bit too lazy to keep checking on activity throughout fermentation - the (potential) game changer... we can work out roughly how much heat energy should be released during fermentation (calculated from the amount of sugar and how much heat yeast produce per frame of sugar converted to alcohol and CO2) and we can measure how much heat a freezer/fridge is removing from the space from how much it is on (and a bit more maths, plus factoring in any losses to the general atmosphere), so by comparing how much energy has been remove by the fridge with the total expected to be remove we could estimate roughly how far through fermentation we are at... I think

So the question - do you guys see any big hurdles I haven't seen or assumption that don't make sense? Just so I don't waste a whole lot of time... but I do have 3 more weeks at least to fill so I will probably dig out some of my old Arduino gear to see what I have and how far I can take it...
I don't really understand how it works. In my experience, the temperature of environment dominates the cooling frequency. Let's say, setting the temperature 68F, my fridge runs frequently when it is 90+F, and it merely runs when it is 65F or under.

IMO, gravity checking is the way to go, iSpindel has working great for me. I can control the temperature based on the gravity readings.