Was thinking that too @mdma, but if the pressure (i.e. rate of outgas) is higher than the static pressure of the sterilizer solution in the blow-off tube reservoir (i.e. the fluid pushing back on the blow-off tube), then there will be a void in the tube below the water level. Check out my video above… in your case though it seems the pressure is low, because you have a smaller volume?
Just like blowing bubbles in your milk through a straw.
But if the pressure is low, it will build up over time and overcome the static pressure of the sterilizer, level in the tube will drop below the surface of the rest of the sterilizer… once the bubble comes out, pressure is temporarily relieved and fluid flows back up the tube until pressure builds again.
If density of the beer is a better gauge though, might make more sense to tackle that problem first.
Sure, there will be a void but it is temporary until the pressure is released by the bubble. It’s exactly that void/release cycle that we’re trying to measure. so I don’t see why we couldn’t use the same conductance technique as I used with the airlock?
Alas, measuring SG directly is a far harder problem, and usually requires insertion of something into the beer. I figured I’d tackle the easy one first since it’s non-intrusive to the beer.
also a homebrewer and was looking for some free time to tackle this problem. ive had some batches where my cellar got too cold and the yeasts output slowed to a crawl. itd be nice to know when thats happening, so i dont need to repitch a new colony
In any case, i was planning on using a mic to record the sound and do a +1 every time a bubble escaped. nice thing about that is that it could be attached to the outside of the airlock instead of the inside. might also work for a blowoff tube as well.
ill let you know how that turns out. next thing on my list after that is a climate control to get those carboys fermenting at the ideal temperatures… instead of whatever temp my basement wants to be at.
Hi @Pat, good luck with your bubble listener project! For climate control, brewpi is good - it’s what I use (disclaimer: I’m a major contributor to the project.) I use it both in a fridge, and to control a panel heater in my brewery.
Awesome work! I’m also a homebrewer down in Aus and have been involved in getting shields out for the Brauduino Project - a controller to control stepped mashing using heating elements and a pump ala the Braumeister.
are the main threads on it. Anyway, the controller is pretty mature now and some Italians are extending it even further - saving mashing schedules and all sorts of cool stuff.
So - enough background - I was thinking it would be awesome to have the next step to have the controller having wireless and push notifications to smartphones for next steps / hop additions / remove malt pipe and allow people to program it from their phone. So I was thinking spark core.
I was also wondering if having the spark core in the box with the 12v powersupply, ssr, and behind the shield would stop the wireless from working well.
Any thoughts? Any help / advice very gratefully received.
I am wondering of the conceptual scale… what the bubble-sensor is looking for is a clear tube to count the bubbles. Not distraction from, i.e. blowing out yeast and other liquid?
What about this?
Fermentor has a blowoff tube. blowoff tube ends in sanitizer in a large tall bucket (or large glass jar) with lid… regular airlock (the one with the S shape inside), without the cap is used on top of the lid to use the bubble-sensor.
@mdma, I wanted to dig this up and see if you’ve made any changes. I want to make something very similar to this. I believe the photon will be the best so I can log via wifi and perhaps even power with a battery. For the sensors I was considering using one of the photogate sensors on a 1 piece airlock.
I also considered using some kind of accelerometer on the 3 piece airlock or or just a motion sensor. I’m really just trying to get a rough idea of fermentation activity so I can possibly raise temperature remotely if it appears activity has slowed.
How has yours been working? What kind of interface are you using to view the activity?
