remthewanderer
Well-Known Member
So. I want to track my fermentations a little better. I have brewpi installed on one of my raspberry pis. I know that this can track my temps just fine and it can integrate with arduino boards.
The holy grail for me would be the ability to see my specific gravity as it drops to get a ROUGH idea of whether or not fermentation is complete. I say rough idea because I just want a visual way to tell if a batch is ready to keg, I don't need to know if it finished at 1.010 or 1.015. This would be a nice to have feature but not necessary.
I've racked my brain and the best general solution I have come up with is to measure the capacitance of the wort and then use some math to translate that into SG. I've seen some charts on a salt water aquarium forum that did this math so I think capacitance measurements can correlate to SG.
But how to actually take capacitance measurements? I figure a food safe probe of some sort submerged in the wort. Pre-made EC probes are REALLY expensive. Enter the Arduino and the Capsense library.
Here is the hurdle for me right now: I don't currently own an arduino board.. I know that the cap sense library is used for touch based sensors and that people have used simple, food safe metals (could I use some stainless wire?) as the leads for home made EC probes. I have to assume that the capsense lib will output an integer or decimal value based on capacitance reading from the probe. I'm not 100% sure but I think the capacitance of wort will drop as the sugars change to alcohol. Can someone shed light on this? From this number I could work the math to get an SG or at the very least graph the number to see when it levels out.
Has anyone done anything similar? I've seen the beerbug kickstarter project which claims to measure SG but I have never read how they do it.
PS: How do large breweries know when their fermentation is complete? Do they take hydrometer readings manually or do they know that recipe X takes Y days to ferment out completely.
Can anyone here help shed some more light on how to digitally measure SG? I will gladly give you 1,000 internet points!
The holy grail for me would be the ability to see my specific gravity as it drops to get a ROUGH idea of whether or not fermentation is complete. I say rough idea because I just want a visual way to tell if a batch is ready to keg, I don't need to know if it finished at 1.010 or 1.015. This would be a nice to have feature but not necessary.
I've racked my brain and the best general solution I have come up with is to measure the capacitance of the wort and then use some math to translate that into SG. I've seen some charts on a salt water aquarium forum that did this math so I think capacitance measurements can correlate to SG.
But how to actually take capacitance measurements? I figure a food safe probe of some sort submerged in the wort. Pre-made EC probes are REALLY expensive. Enter the Arduino and the Capsense library.
Here is the hurdle for me right now: I don't currently own an arduino board.. I know that the cap sense library is used for touch based sensors and that people have used simple, food safe metals (could I use some stainless wire?) as the leads for home made EC probes. I have to assume that the capsense lib will output an integer or decimal value based on capacitance reading from the probe. I'm not 100% sure but I think the capacitance of wort will drop as the sugars change to alcohol. Can someone shed light on this? From this number I could work the math to get an SG or at the very least graph the number to see when it levels out.
Has anyone done anything similar? I've seen the beerbug kickstarter project which claims to measure SG but I have never read how they do it.
PS: How do large breweries know when their fermentation is complete? Do they take hydrometer readings manually or do they know that recipe X takes Y days to ferment out completely.
Can anyone here help shed some more light on how to digitally measure SG? I will gladly give you 1,000 internet points!