Brewometer kickstarter thoughts - digital bluetooth hydrometer

[Murphys_Law]

This is a cool little device. I'm not looking for absolute numbers but rather trends. I like being able to see when fermentation flattens out and then I check SG with a hydrometer for my records.

 

[BrunDog]

this is a cool little device. I'm not looking for absolute numbers but rather trends. I like being able to see when fermentation flattens out and then i check sg with a hydrometer for my records.

+1000

 

[55x11]

I am glad that silly Amazon talk is over...

No surprise on temp affecting the reading. My guess is they have to better understand and manage the device's correlation between temp and gravity. I would bet the lag between the body temp and the sensor temp wreaks havoc on the calculations.

But at the end of the day it is a very cool device and platform that is good now for the money. It will only get better with fine tuning and updated supporting applications. It's not perfectly accurate in one single reading but certainly over the course of a short period of time, it's average it pretty much spot on.

I just cold crashed beer after ramping up fermentation temperature to dry it out just one final bit. So a drop from 70F to about 28-30F and Gravity was stable within a few points. Density of liquid doesn't change that much there but it seems their correction for temperature works just fine.

 

[EternalHoppiness]

I'm pretty impressed with the device, and find great utility in tracking SG to know when to adjust temperature, etc. But the other thing I learned on my first ferment had more to do with my temp control. Having temp logging near the surface of the beer is pretty useful.

A little background on my setup:
- Upright freezer with dual stage love controller
- Temp probe in thermowell in the center of a better bottle fermenter
- Heating accomplished with fermwrap
- Temp threshold set at 0.4 degrees single stage (without heater)
- Temp threshold set at 1.0 degrees dual stage (when heater needed)

I always assumed this worked fairly well, but never logging temp in the beer, never knew for sure. In the attached plot, you can see that this worked pretty well while fermentation was active. Temperature was very stable because moving liquid kept temperature at center of fermenter the same as temperature at surface of fermenter. However, as fermentation finished and the beer stopped moving, I started getting 2-4 deg F swings due to delay in cooling the center of the beer relative to the surface. (The change in average temp was due to a two step ramp of set point near end of fermentation).

So on 5/24, I moved the temp probe to the outside of the fermenter, covered with foam and taped in place. From that point on, the temperature variation was mostly less than the 1 deg resolution of the brewometer. Very interesting.

For my next batch, I plan to start out in this configuration (probe covered in foam and taped to fermenter) and see what the beer temp does. At the very least, I think my new procedure will include moving probe out of thermowell once fermentation is complete.

I expect the question: Does this 2-4 deg temp change matter? I am leaning toward yes due to air exchange as the temperature changes (S airlock bubbles both ways), but am open to other thoughts.

Anyway, I'm enjoying the new toy and have had no problems so far. Thinking about a second brewometer, as the visual progress in the second fermenter is a little different, even though everything should be identical (split 10g batch). Sorry for the long-winded post, but just thought I'd share my learning experience. I'm sure everyone's system is a little different, but the opportunity to learn one's own is pretty cool.

One other note: The SG drop at the beginning (and associated rise after 12 hours) is due to adding my yeast starter, which stayed layered at the top (where brewometer floats) until fermentation got active.

 

[55x11]

I'm pretty impressed with the device, and find great utility in tracking SG to know when to adjust temperature, etc. But the other thing I learned on my first ferment had more to do with my temp control. Having temp logging near the surface of the beer is pretty useful.

A little background on my setup:
- Upright freezer with dual stage love controller
- Temp probe in thermowell in the center of a better bottle fermenter
- Heating accomplished with fermwrap
- Temp threshold set at 0.4 degrees single stage (without heater)
- Temp threshold set at 1.0 degrees dual stage (when heater needed)

I always assumed this worked fairly well, but never logging temp in the beer, never knew for sure. In the attached plot, you can see that this worked pretty well while fermentation was active. Temperature was very stable because moving liquid kept temperature at center of fermenter the same as temperature at surface of fermenter. However, as fermentation finished and the beer stopped moving, I started getting 2-4 deg F swings due to delay in cooling the center of the beer relative to the surface. (The change in average temp was due to a two step ramp of set point near end of fermentation).

So on 5/24, I moved the temp probe to the outside of the fermenter, covered with foam and taped in place. From that point on, the temperature variation was mostly less than the 1 deg resolution of the brewometer. Very interesting.

For my next batch, I plan to start out in this configuration (probe covered in foam and taped to fermenter) and see what the beer temp does. At the very least, I think my new procedure will include moving probe out of thermowell once fermentation is complete.

I expect the question: Does this 2-4 deg temp change matter? I am leaning toward yes due to air exchange as the temperature changes (S airlock bubbles both ways), but am open to other thoughts.

Anyway, I'm enjoying the new toy and have had no problems so far. Thinking about a second brewometer, as the visual progress in the second fermenter is a little different, even though everything should be identical (split 10g batch). Sorry for the long-winded post, but just thought I'd share my learning experience. I'm sure everyone's system is a little different, but the opportunity to learn one's own is pretty cool.

One other note: The SG drop at the beginning (and associated rise after 12 hours) is due to adding my yeast starter, which stayed layered at the top (where brewometer floats) until fermentation got active.

to me, the 1 deg F resolution in temperature is annoying and surprising. I would imagine that any thermocouple even a cheap one, can do 0.1-0.2F easily. Even 0.3F would be ok by me.

SG values have an excellent resolution of 1 gravity point but fluctuate randomly by 2-3 points so that's not useful. Yet temperature is stable to within 0.1F and they don;t have thermocouples that could measure that?

 

[LBussy]

It's not perfectly accurate in one single reading but certainly over the course of a short period of time, it's average it pretty much spot on.

I think the main issue with any given reading is the potential for there to be either krausen or bubbles adhering to the device. One of those new super-hydrophobic materials as a coating would be an interesting experiment, but I contacted the coating manufacturer and they stated they are not rated for food contact.

Anyone want to make a side by side sacrificial batch of beer and see the difference in readings with a coating on a device?

 

[Derp]

I always assumed this worked fairly well, but never logging temp in the beer, never knew for sure. In the attached plot, you can see that this worked pretty well while fermentation was active. Temperature was very stable because moving liquid kept temperature at center of fermenter the same as temperature at surface of fermenter. However, as fermentation finished and the beer stopped moving, I started getting 2-4 deg F swings due to delay in cooling the center of the beer relative to the surface. (The change in average temp was due to a two step ramp of set point near end of fermentation).

So on 5/24, I moved the temp probe to the outside of the fermenter, covered with foam and taped in place. From that point on, the temperature variation was mostly less than the 1 deg resolution of the brewometer. Very interesting.

Very interesting. I've only had my Brewometer for about a week, so when it arrived I just chucked it into a 13-gallon batch of beer that had already finished fermenting. The gravity readings didn't fluctuate much (mainly between 1.007 and 1.01), but the temperature readings bounced between 68 (the setpoint temperature) and 72. That upper level worries me a bit.

My setup is a plastic, 60-liter Speidel fermenter in a chest freezer. I just fit an orange carboy cap over the top of the hole in the lid and insert a stainless thermowell into the large opening and put a blowoff hose over the smaller opening. I put the other end of the hose in a container of StarSan. I never have blowoff problems with the Speidels, so it really just serves as an airlock.

The thermowell puts the temperature sensor for the Brewbit controller right in the center of a 10-gallon batch. I had the controller set for 68 degrees with a 0.5-degree threshold and it did a good job of keeping the (center of) beer between 67.5 and 68.5 by cycling the chest freezer's compressor and a 50W reptile heater that's taped to the walls of the freezer.

It's clear that the Brewometer's temperature readings fluctuated in sync with the freezer/heater cycles, but they rose about 3.5 degrees higher than the thermowell reading and that concerns me. I'll probably leave things alone for a first full fermentation cycle (I might ferment a couple of degrees cooler than planned) but if I still see such large swings I'll try taping the temperature probe to the outside of the Speidel to see if it helps things.

Thanks for sharing your info!

 

[arfenarf]

I'm having a wonderful time with this and am poking around with the spreadsheet some more.

I've noticed a few things. First, I think it's an error to make the graph a line graph. What we're really looking at is a scatter plot. The 1 degree resolution is what it is and it makes more sense if the eye (or your trendline) helps you smooth the actual data without all the noise of misleading lines.

Second, be aware that the reports and graph have a default filter of 10 days on them. This is all cool, but if you're calculating ABV or attenuation over the content of that front page report, your pretty gauges will be misleading as the OG scrolls out of your 10-day window in a long ferment. I think I'm going to see this as I get my 10-day-old Maibock up into its diacetyl rest before kegging and lagering. In the next version, I'll hard-code my OG so the gauges don't lose sight of the value if I keep the report filters at 10 days.

 

[LBussy]

One thing I've noticed about these graphs: People are using trend lines. A "moving average" may be a better indicator. Not sure if this is a graph that someone here developed or if it "comes with" the device.

 

[Derp]

In the next version, I'll hard-code my OG so the gauges don't lose sight of the value if I keep the report filters at 10 days.

That's what I did. I entered the OG (as measured by refractometer) and predicted FG manually for gauges displaying the current ABV and the percentage of fermentation completed.

 

[Derp]

One thing I've noticed about these graphs: People are using trend lines. A "moving average" may be a better indicator. Not sure if this is a graph that someone here developed or if it "comes with" the device.

The inventors developed a Google Sheets template which they've shared on their website and it contains the trend lines. I agree that it's not of much use. I also agree that scatter plots are easier on the eye than the mass of connected lines.

 

[arfenarf]

One thing I've noticed about these graphs: People are using trend lines. A "moving average" may be a better indicator. Not sure if this is a graph that someone here developed or if it "comes with" the device.

I completely agree and expect to put it into my V2.

(You know, I used to obsess about the next batch in terms of wanting to try to make something cool out of barley, yeast, and hops. Now I'm *also* obsessing about the next batch in terms of wanting to make something cooler out of the data.)

A linear trendline isn't much use for an exponential process. FWIW, though, I can't get Google Sheets to put a polynomial or exponential trend on this graph no matter how much I glare at it before clicking the button.

 

[BrunDog]

to me, the 1 deg F resolution in temperature is annoying and surprising. I would imagine that any thermocouple even a cheap one, can do 0.1-0.2F easily. Even 0.3F would be ok by me.



SG values have an excellent resolution of 1 gravity point but fluctuate randomly by 2-3 points so that's not useful. Yet temperature is stable to within 0.1F and they don;t have thermocouples that could measure that?

The temp sensor is not a thermocouple. It is a digital sensor, and it is mounted to the circuit board in the device. It is not in contact with the wort. Go back a few pages and you can see where we discussed it's accuracy.

If you are concerned with dead on SG accuracy, use a hydrometer. If you are interested in the trend, then the 2-3 SG point swing is no big deal. You are expecting too much for an electronic device like this at this price point to have 0.001 accuracy. The resolution is easy to do... But accuracy is another animal.

 

[BrunDog]

Very interesting. I've only had my Brewometer for about a week, so when it arrived I just chucked it into a 13-gallon batch of beer that had already finished fermenting. The gravity readings didn't fluctuate much (mainly between 1.007 and 1.01), but the temperature readings bounced between 68 (the setpoint temperature) and 72. That upper level worries me a bit.

My setup is a plastic, 60-liter Speidel fermenter in a chest freezer. I just fit an orange carboy cap over the top of the hole in the lid and insert a stainless thermowell into the large opening and put a blowoff hose over the smaller opening. I put the other end of the hose in a container of StarSan. I never have blowoff problems with the Speidels, so it really just serves as an airlock.

The thermowell puts the temperature sensor for the Brewbit controller right in the center of a 10-gallon batch. I had the controller set for 68 degrees with a 0.5-degree threshold and it did a good job of keeping the (center of) beer between 67.5 and 68.5 by cycling the chest freezer's compressor and a 50W reptile heater that's taped to the walls of the freezer.

It's clear that the Brewometer's temperature readings fluctuated in sync with the freezer/heater cycles, but they rose about 3.5 degrees higher than the thermowell reading and that concerns me. I'll probably leave things alone for a first full fermentation cycle (I might ferment a couple of degrees cooler than planned) but if I still see such large swings I'll try taping the temperature probe to the outside of the Speidel to see if it helps things.

Thanks for sharing your info!

I probably should not go down the rabbit hole, but driving a refrigeration controller of of the temp probe in the center of your wort will cause a lot of stratification. The wort near the surface of the fermenter will end up much colder than the center by the time the sensor and the controller's hysteresis gap tells the compressor to cycle off. That creates the temp swings. The Brewometer is at the top surface of the liquid, so expect it to read dramatically different temps than the center.

 

[Derp]

I probably should not go down the rabbit hole, but driving a refrigeration controller of of the temp probe in the center of your wort will cause a lot of stratification. The wort near the surface of the fermenter will end up much colder than the center by the time the sensor and the controller's hysteresis gap tells the compressor to cycle off. That creates the temp swings. The Brewometer is at the top surface of the liquid, so expect it to read dramatically different temps than the center.

I knew there would be stratification issues, but I didn't realize that the temperature between the center of the vessel and the top would vary by almost 4 degrees until the Brewometer showed me, so it's already proven itself worth the price of purchase.

I have 3 logging temperature devices (Brewometer and 2 Brewbit probes) so for my next batch I'll try to use them all. I'll stick one probe to the side of the fermenter with some insulation and maybe I'll try pulling the other up the thermowell so that it's only an inch or two below the surface. Not sure how much heat/cold the stainless thermowell will conduct from above/below, but it'll be interesting to see.

I also have a fan that I've been meaning to install in the chest freezer. That should help even out the ambient air temperature.

I would expect stratification to be less of an issue during active fermentation while the wort is churning around the fermenter, right? All in all, I'll be happy with a 1-degree swing. That's what I already have a the center of the Speidel, but I'd just like to make sure that there aren't parts of it hitting the 70s.

 

[EternalHoppiness]

I knew there would be stratification issues, but I didn't realize that the temperature between the center of the vessel and the top would vary by almost 4 degrees until the Brewometer showed me, so it's already proven itself worth the price of purchase.

I have 3 logging temperature devices (Brewometer and 2 Brewbit probes) so for my next batch I'll try to use them all. I'll stick one probe to the side of the fermenter with some insulation and maybe I'll try pulling the other up the thermowell so that it's only an inch or two below the surface. Not sure how much heat/cold the stainless thermowell will conduct from above/below, but it'll be interesting to see.

I also have a fan that I've been meaning to install in the chest freezer. That should help even out the ambient air temperature.

I would expect stratification to be less of an issue during active fermentation while the wort is churning around the fermenter, right? All in all, I'll be happy with a 1-degree swing. That's what I already have a the center of the Speidel, but I'd just like to make sure that there aren't parts of it hitting the 70s.

I agree with this completely. I didn't expect the variation between wort center and wort surface to be so large. Even with a fan running continuously I got the 4 degree swings after fermentation was done. As you say, learning this has already made me satisfied with the purchase.

I would be curious to see the results of that 3-point logging experiment. My results seem to support your statement that stratification will be less of an issue during active fermentation. I had thought that the thermowell would be the best for temp control, but I guess the hysteresis that BrunDog mentioned means that's only true during active fermentation or if you have a PID control like the BrewPi. Brewing is a constant learning experience!

 

[55x11]

The temp sensor is not a thermocouple. It is a digital sensor, and it is mounted to the circuit board in the device. It is not in contact with the wort. Go back a few pages and you can see where we discussed it's accuracy.

If you are concerned with dead on SG accuracy, use a hydrometer. If you are interested in the trend, then the 2-3 SG point swing is no big deal. You are expecting too much for an electronic device like this at this price point to have 0.001 accuracy. The resolution is easy to do... But accuracy is another animal.

I agree - the brewometer is best for figuring out the trends, I still use hydrometer (finishing hydrometer is best for that, with 0.990-1.020 range) to figure out the final SG. Just saying that the precision of 1 SG points while there are substantial fluctuations of 2-3 SG (not a big deal if you are looking for trends) is overkill, and I would rather have record of rolling average than a highly precise but inaccurate SG.

1F resolution in temperature on the other hand is a bit coarser than I would require. Having 0.2F, 0.3F or 0.5F accuracy would help a great deal.

 

[raysmithtx]

For those wanting to use a Kindle Fire tablet with the Brewometer. Apparently Amazon runs an update EVERY night between 2-4 AM and the app will stop. You have to activate the app. again every morning. Not a big problem for me, just something I thought others might like to know. I have confirmed that the update is the problem because when I look at the time of the 'last update' on my Kindle Fire tablet, it has coincided with the time the app. stops working every night for the last 5 nights.

I'm still a Brewometer fan.

 

[Arminius757]

This thing looks pretty sweet. I am still a college student and live on campus most of the year. I dont like dragging all my gear back and forth from college so I mostly brew at home on breaks and weekends when I have time. The biggest issue for me is keeping an eye on my beer when Im not home. I currently have a chest freezer that I use as a fermentation chamber in the garage but I have no way to check on my beer. I plan to change this by building a BrewPi for temperature control but this might come in handy too. Now if only someone could hook this up to BrewPi so that I could get both my temp and gravity readings on one device, that would be amazing. I have an old ipod laying around that I could use to send out the data to the cloud so I guess I could monitor it there... Maybe I can see if I can get some of my other engineering buddies to help me build and code a device like this for the BrewPi...

 

[LBussy]

I have seen the data integrated with the BrewPi, the only issue is the data is so "rough" one needs Excel or Google Sheets to show the trend lines to make sense of it.

 

[day_trippr]

I have seen the data integrated with the BrewPi,[...]

Link?

Cheers!

[edit] nvm, found an example:

Woof.

'Course, that's two Brewometer traces, but still, hella busy...

 

[Arminius757]

Link?

Cheers!

[edit] nvm, found an example:

Woof.

'Course, that's two Brewometer traces, but still, hella busy...

Yeah I found a few posts on the BrewPi forms with some people trying to integrate this better. As of right now though, you would need to edit the data second hand like you mentioned to really make sense of it... Though I have also read that a SG sensor is in the works for the BrewPi, but is on the backburner until they find a way to use the BrewPi to control mash temperatures and such... Still, might be an interesting project to look into. The BrewPi integration is still rather new.

 

[jmitchell3]

The temp sensor is not a thermocouple. It is a digital sensor, and it is mounted to the circuit board in the device. It is not in contact with the wort. Go back a few pages and you can see where we discussed it's accuracy.

If you are concerned with dead on SG accuracy, use a hydrometer. If you are interested in the trend, then the 2-3 SG point swing is no big deal. You are expecting too much for an electronic device like this at this price point to have 0.001 accuracy. The resolution is easy to do... But accuracy is another animal.

After 3 batches with my brewometers ive found a simple moving average over 3-8 hours to be quite accurate. FG numbers were also right on the money using the SMA comoared to my hydrometer (this of course assumes a calibrated brewometer....)

 

[Natdavis777]

Mine is ordered. I am anxious to use it in the next brew.

 

[CaptnDelta]

Yeah I found a few posts on the BrewPi forms with some people trying to integrate this better. As of right now though, you would need to edit the data second hand like you mentioned to really make sense of it... Though I have also read that a SG sensor is in the works for the BrewPi, but is on the backburner until they find a way to use the BrewPi to control mash temperatures and such... Still, might be an interesting project to look into. The BrewPi integration is still rather new.

I got my brewpi running for a few days now with the brewpi+ brewometer integration by sbowler, and after his averaging fixes and with some tweaking on the graphing I think I now like how this looks...

There are also updated instructions on his github page.
Cheers,
-Th

 

[LBussy]

Now that's something that's able to be read ... I like it. I might tweak a little more if it was me but it's definitely a step in the right direction.

 

[jmark]

I got my brewpi running for a few days now with the brewpi+ brewometer integration by sbowler, and after his averaging fixes and with some tweaking on the graphing I think I now like how this looks...

There are also updated instructions on his github page.
Cheers,
-Th

I would assume these are just additions to the RPI side of things, but just want to make sure those tweaks work with the Arduino version of Brewpi (i.e. the legacy branch) and not the newer branch?

Also - any recommendations for a good USB hub to add to a RPI2 since mine only has two ports... 1 for power and 1 for the Wifi dongle and for this I'll need to add a BLE dongle as well.

 

[day_trippr]

[...]Also - any recommendations for a good USB hub to add to a RPI2 since mine only has two ports... 1 for power and 1 for the Wifi dongle and for this I'll need to add a BLE dongle as well.

All of my RPi2 boards have the standard twin dual-stacked USB headers for four ports. I'd guess yours is actually an RPI Model B.

I've used three different powered four port USB2 hubs with both my Model B's and my RPi2's and they all work just fine. My favorite is this uber cheap tiny cube that was great for integration inside small cases - and that I can't find for sale any more (not helpful, I know).

Anyway, don't bother with USB3 hubs, the bandwidth available is nowhere near capable of even saturating a USB2 link. And cheap is fine...

Cheers!

 

[CaptnDelta]

I would assume these are just additions to the RPI side of things, but just want to make sure those tweaks work with the Arduino version of Brewpi (i.e. the legacy branch) and not the newer branch?

Also - any recommendations for a good USB hub to add to a RPI2 since mine only has two ports... 1 for power and 1 for the Wifi dongle and for this I'll need to add a BLE dongle as well.

(1) yes, doesn't matter if arduino or spark, etc, the brewometer changes only affect the RPi side.
(2) You could also try to see if there is a combo wifi/bluetooth dongle around that works with Raspbian. Just make sure it supports BT4/BLE.

Cheers,
-Th

 

[TorMag]

Just pulled the trigger and ordered a blue one....