An electronic hydrometer I'm working on

[barneey]

Very possibly

But I quite like the idea of the beerbug thing , boys and toys........... http://www.thebeerbug.com/

[orlando]

Very possibly

But I quite like the idea of the beerbug thing , boys and toys........... http://www.thebeerbug.com/

It is good and I would love one but not at that price.

[chris2012]

I tried out making something using a load cell, which afaik is what beer bug used originally, but found far too many issues with drift.
I'll see if i can dig out a photo of that setup.

I'm starting work on a system which uses ultrasound, but it will be a lot more complex to make, as it requires accurately computing the speed of
sound and also amplitudes of reflected waves.

[chris2012]

This is what it looks like, alas it just was terribly drifty. I even got PCBs made for it
too, oh well back to the drawing board

[barneey]

Do you still have all the bits?

[bobsbeer]

I've also been working on an electronic hydrometer. My initial idea was a floating container in the wort that would relay sg and temp back to a pc using an arduino. To measure the fermentation I have been using conductivity readings. At the moment it is only in the conceptual stage, although I have rigged up a conductivity probe and tested different sugar % water solutions to see what the difference is. At first it was promising, until I tested a glass of red wine at an sg of .992 and that sent the probe haywire which I didn't expect. My only problem is converting the conductivity reading to a known sg reading. They don't seem to correlate, but the conductivity does change during fermentation so presumably would stabilise out once it had finished. For probes I'm using nicad wire which should be reasonably stable. Although it may be better alternating the current. But haven't got that far yet. anyway I look forward to seeing your ultrasound results when you get them.

[chris2012]

bobsbeer - do you mean you're effectively measuring the resistivity of the wort itself? I've not heard of that approach before, sounds interesting.

Clive - yeah I do have the bits still, but it really didn't work out how I wanted in terms of results alas

I've just started a build log here if anyone's interested: http://hackaday.io/project/1231-Zymeter

[orlando]

bobsbeer - do you mean you're effectively measuring the resistivity of the wort itself? I've not heard of that approach before, sounds interesting.

Clive - yeah I do have the bits still, but it really didn't work out how I wanted in terms of results alas

I've just started a build log here if anyone's interested: http://hackaday.io/project/1231-Zymeter

Interesting project. Can I ask why you think pH is important to monitor? Mash pH is of interest but as there is little you can do, or really need to do once fermentation is underway, if this aspect is getting in the way of the rest of the project I would ditch it.

[chris2012]

orlando - yeah I agree with what you're saying in that you can't control it.

It won't be the major feature, but it's something i'm curious about how much it changes over time. As I'm wondering how the pH change could be effected
by different yeasts or lacto/brett strains.

I'll definitely be concentrating on the SG part, first and foremost though.

[bobsbeer]

bobsbeer - do you mean you're effectively measuring the resistivity of the wort itself? I've not heard of that approach before, sounds interesting.

I have started my experiment on three different wines. Not tried a beer wort yet, but I plan on testing all the fermentations I carry out over the next few weeks to test the concept. I have only tested the start and end reading on one so far, as I don't want to risk infection, testing during fermentation, but will be testing at the end to see what the reading is. What I have found is that each brew has a different start reading. For instance a supermarket juice wine had a start reading of 1620, and another 4350, while a top end all grape juice red was at 6450. Testing is being done with a hand held meter prior to pitching. The first one was started 26 days ago and was tested again yesterday. This one started at 4350 and is now 2000. Current SG is .996. It started at 1.089. So a drop of 2350 would appear to be a significant drop. I still have two more to test, so the result can only be provisional at present, but it looks promising.

[basswulf]

This is all way beyond my current competence to cobble together but colour me impressed.

I am just beginning to experiment with a simple temperature logger, powered by a Raspberry Pi and using a DS18B20 sensor; baby steps on the electronics side. Over the past couple of days I've kept it snug against the outside of my fermenting vessel and I've noticed that the temperature was rising gently to begin with but (now that the krausen is beginning to relax), is beginning to fall again. Is temperature alone enough to give some indication that fermentation is working, or, as it settles back, that it has completed?

Ideally I would experiment with several batches and also wire in a second monitor to adjust against ambient temperature in the room. However, from your experience of monitoring fermentation, would that give enough of a clue? I know it won't give me the gravity but it would be great to turn on a little light to alert me that it looks ready to take a sample and start gathering bottles.

Wulf

[chris2012]

I can see the logic in what you're saying, in that fermentation should give off heat, so maybe you could detect it when it's over via temperature.

I've actually used the same DS18B20 sensor with an RPi to measure temp of fermentation too, but for the life of me I don't know if I've got one of the graphs from it (I'll try and have a looky).

I fear that ambient temperature changes would mean you wouldn't notice when the fermentation is finished.

[basswulf]

A two sensor set up (fermentation vessel + ambient) might work through, if the corrected line still demonstrates some kind of rise and fall. Certainly the changes I've seen in my one run so far (started about three days in so not good data) showed a gradual rise through the day and into the night followed by signs of a fall during the (reasonably warm) day today. Maybe I'll do some more tinkering before I start my next brew.

Meanwhile, I'll continue to keep an eye on this thread to see what you come up with.

Cheers,

Wulf

[chris2012]

Random idea, which may/may not be helpful:

You could use an Rpi camera in the fermentation bucket, pointing at a hydrometer