Brew Nanny

[DEMPSEY]

I see this Brewnanny is finally coming to market. http://brewnanny.com/

I wonder is it as good as what Imark made


https://www.youtube.com/watch?v=-eqwzlnj1Z4

[Jacob]

Even BeerBug is cheaper http://www.thebeerbug.com/

[imark]

It's very similar to brewpi which is the software I use. Main difference with brewpi is that it controls the fermentation chamber while this only monitors it from what I can see.

The price is high alright considering I built my brewpi for ~€50.

[imark]

that was a wedding present. Strictly speaking Newbridge silver isn't technically necessary....but it adds a nice bling to the kit.

[Will_D]

Yes its a bit OTT in price.

Appart from temperature sensors and light sensors the only really clever bit of kit is the pressure sensor/regulator and I assume a micro-switch.

This can then measure the rate of CO2 production and hence fermentation progress as follows:

1. Switch is Closed
2. Pressure builds up to 1 psi: Switch Opens
3. Pressure bleeds off through a hole until pressure drops to say 0.2 psi (or whatever): Sw Closed

So by plotting the switching cycles against time you can get the amount of CO2 being produced and so track the ferment. It probably requires an interesting calibration curve which includes temperature correction. This is just software!

So it looks like the only bit of expensive/difficult to source kit needed is this "blow-off micro-switch enabled thingy valve"

So where can we buy one?

[pob]

Something like this?

www.ebay.com/itm/141150545648?cmd=VIDESC&gxo=true

[JD]

@ pob, that board is for connecting to strain gauges for weighing scale applications. Not sure how that will help us here...

@will_d
I'm imagining a stainless steel dip tube within which slides a solid stainless steel rod. This rod is sealed against the side of the tube by an O-ring. The rod pushes up again a light coil spring (like one from a ball point pen) . A hole in the side of the tube becomes exposed exposed when the rod is pushed up by the CO2 pressure. This releases the pressure. A micro-switch detects when the rod reaches this point. When the pressure is relieved sufficiently the spring pushes the rod back down and the cycle repeats. The micro-switch open and close times will give you an indication of the rate of CO2 production just like "brewnanny" (terrible name, by the way).

[pob]

It can also be used as pressure sensor, e.g. Put it tube as above but instead of micro switch, allow CO2 build up, then vent (mechanical bubble) then count number of times the valve opens in timeframe, similar to counting bubbles in airlock, i.e. higher number = more vigorous fermentation.

Was also looking at the MG811 CO2 sensor, they are <€30 though, could explain the price of the Brewnanny.

Would the level of sealing & insulation to prevent false readings, when any sensitive sensor is used, make it a pain in the a to make or indeed use in our brew areas?

In the meantime I'll continue on my BrewPi variations ;-)