Brewometer kickstarter thoughts - digital bluetooth hydrometer

[user 204491]

fwiw, I run into this all the time here, and the sure fire way to get the text across intact is to stick it inside a CODE block...

=sum(INDIRECT("D"&COUNTA(D:D))-D2)*131.25

Cheers!

Ahh, thanks! Looks like the CODE block is only accessible from the advanced tab, but will remember it for the next time!

 

[Carlscan26]

I still see a smiley face

 

[BrunDog]

Me too but looking on the HBT app.

 

[rafaelpinto]

Seems awesome.

Can it be used during mash?

 

[user 204491]

Seems there's nothing preventing you from using it during the mash, as it says the temp range is 32F - 185F.

 

[ChrisL_]

Very interesting. It can certainly handle the temperature reading. Great to be able to monitor it remotely if you do not have a temp controlled recirculating mash. I wonder about the ability to read the gravity with all the grain in there? A typical mash is likely too thick, but I do full volume BIAB. Won't likely be pinpoint accurate but even close reading of gravity, with the temp of a mash charted would be cool.

 

[pepindavid]

I suspect something similar: mine had been hovering between 1.011 and 1.014 for about 48 hours. When I hiked up the temp (about 2 F), the gravity also went up, with most readings between 1.015 and 1.018. It now seems to have stabilized between 1.014 and 1.016. It

Update: I shared my spreadsheet with the developers, because I thought that the fluctuations were a bit unusual: (from 1.011 to 1.018 is quite significant). I still had it today going down to 1.012, and up to 1.017).

The developers looked at the data and think it shouldn't fluctuate that much: they will send me a new device, and include a return envelope for the one I have (they want to take a look at it to try to understand what is causing the problem).

So far, I am really impressed with their customer support.

 

[user 204491]

Hey, gang, looks like they released an update for the app today and the developer sent me some new instructions regarding calibration (you'll need the new app to follow these steps).

Regarding calibration, they should come pre-calibrated, if it seems off when floating in water, tap the gear icon, select the color of brewometer you want to calibrate and press the tare button to zero the gravity to 1.000.
If additional points are desired, prepare solutions of your approximate starting and finishing gravity (i.e. 1.015 and 1.060). Make sure there are no bubbles attached to Brewometer when calibrating.
Temperature doesn't matter if calibrating 68F (+/- 30) degrees. The polycarbonate body has similar expansion coefficient to water and so does not need temperature compensation in this range. Above this range, we've noticed about a 1 gravity point decrease per 10 degree increase in temperature, so water at around 110F would read 0.999, 120F would read 0.998 and so on.

I asked him about the correlation we're noticing between temp and gravity swings, and I'll let you know what he says once I hear back!

 

[enkamania]

I started a batch yesterday and so far, so good. I've added some averages to the spreadsheet, so towards the end I can see how long it's been stable. One issue I found is that when you calibrate the temperature, it doesn't like a number with a decimal.

 

[akthor]

Until they fix it so you don't have to recalibrate it every time I'm out. The whole point for me is that my old tired eyes have trouble reading a hydrometer.

 

[BrunDog]

Supposedly it's fixed. I did not have to calibrate mine, so I haven't tested it. But it is supposedly working.

 

[user 204491]

Yeah, as far as I'm aware that issue has been fixed with the recent app update. While the developer didn't specifically call it out in the email they sent me it does appear to be retaining the data in the app. One thing to keep in mind though is that you are essentially calibrating the app to work correctly with the unit, not storing a calibration on the unit itself. So, if you use multiple devices to connect to the same unit, you will need to calibrate each instance of the app you're using.

I calibrated my two new units yesterday using RO water. The new calibration function really makes it a breeze. They both needed only minor changes to gravity (1-2 points); however, they were both off pretty significantly on temp (6-8 degrees). I don't have them in beer yet, but that will change this weekend.

 

[pepindavid]

A replacement has been sent to me. Will take some time to get here, but I should have it available for my next brew day.

The one I will send back to them was clearly affected by temperature changes (they seem to think that it's not possible, but the numbers don't lie). It was sitting pretty stable between 1.014 and 1.016 at around 69F, and then I cold crashed... The gravity went all the way down to 1.007 during cold crash.

The hydrometer reading at bottling was 1.015.

You can see data here: https://docs.google.com/spreadsheets/d/1u-QkUrCMsuJI8hCLVCfRX8KP9mnfk2s0WHdBucVxz30/edit?usp=sharing

(You also may notice a big drop in gravity before I cold crashed: that's when I dry hopped. My guess is that device floated differently with thick layer of hop particles and gave wrong readings.).

We'll see if the next one is as sensitive to temp changes!

 

[user 204491]

I pretty much had the exact same experience with the unit I'm sending back to them. You can see my graph here.

Notice that things just got crazy during the cold crash. Temp swings +/1 20F, and gravity swings going right along with them +/1 9 points. The entire time the beer was sitting at 33F +/1 2 degrees, and the gravity never changed from the 1.009.

The developers were great though, insisted on replacing the unit, shipped out a new one right away, and they've been very communicative throughout the process. They told me on Thursday of last week that they were having a meeting that evening, and one of the topics was my wild temp/gravity swings and their correlation.

 

[dfborn]

So, I've had mine new unit sitting in RO water since Saturday. SG has risen steadily with occasional dips of a point or two. It's up to 1.006 now but has been as high as 1.009. The temp isn't swinging. I calibrated it initially in water.

Any ideas?

 

[LBussy]

So, I've had mine new unit sitting in RO water since Saturday. SG has risen steadily with occasional dips of a point or two. It's up to 1.006 now but has been as high as 1.009. The temp isn't swinging. I calibrated it initially in water.

Any ideas?

I'd be curious if there were tiny bubbles forming on it. Any chance to tap it just a bit?

 

[BrunDog]

Would say same. Tap it or take it out and put it back in.

 

[BrunDog]

I pretty much had the exact same experience with the unit I'm sending back to them. You can see my graph here.

Notice that things just got crazy during the cold crash. Temp swings +/1 20F, and gravity swings going right along with them +/1 9 points. The entire time the beer was sitting at 33F +/1 2 degrees, and the gravity never changed from the 1.009.

The developers were great though, insisted on replacing the unit, shipped out a new one right away, and they've been very communicative throughout the process. They told me on Thursday of last week that they were having a meeting that evening, and one of the topics was my wild temp/gravity swings and their correlation.

Keep in mind the electronics were not made by Brewometer. My guess is they buy the board off the shelf. The temp swings must either be a faulty temperature sensor or the math they use to perform calculations. The probability of a several faulty sensors should be very low, so I believe something else is going on there.

Also, the published temp accuracy for the temp sensor is +/- 3 degs C.

 

[dfborn]

I'd be curious if there were tiny bubbles forming on it. Any chance to tap it just a bit?

Did this and that seemed to fix it. Is this because of the RO water off-gassing ? Should I expect the same kind of performance in wort? (I can't really take it out then...)

 

[pepindavid]

Did this and that seemed to fix it. Is this because of the RO water off-gassing ? Should I expect the same kind of performance in wort? (I can't really take it out then...)

I had the exact same problem with mine when I tested in water. Simply swirling the fermenter corrected the situation. The same happened when I dry hopped: the device got "stuck" in the thick green layer, and the readings were off. Swirling did the job.

 

[user 204491]

Keep in mind the electronics were not made by Brewometer. My guess is they buy the board off the shelf. The temp swings must either be a faulty temperature sensor or the math they use to perform calculations. The probability of a several faulty sensors should be very low, so I believe something else is going on there.

Also, the published temp accuracy for the temp sensor is +/- 3 degs C.

Ahh, sorry, not sure what happened to what I typed there...

My temp readings were swinging +/- 20F and my gravity readings were swinging +/- 9 points, correlated to the temp swings.

I'll be getting one of my two new units in some wort this weekend and start logging things again to see if there's any difference.

 

[303Dan]

Keep in mind the electronics were not made by Brewometer. My guess is they buy the board off the shelf. The temp swings must either be a faulty temperature sensor or the math they use to perform calculations. The probability of a several faulty sensors should be very low, so I believe something else is going on there.

Also, the published temp accuracy for the temp sensor is +/- 3 degs C.

Wow, the sensor is only accurate to +\- 3 degrees C? I've been paying close attention to this thread because this sort of thing is right up my alley, but my primary concern with this (and the beer bug before it) is reasonable accuracy. For me to buy (and I'd be willing to pay more money if necessary), I think I'd need about +\- 1 degree F and +\- .001 on SG. To me, +\- 3C (5.4 degrees F) isn't even useful. But that's just what I'm looking for. I'm sure the information it provides can be useful.

And I understand they're trying to hit a price point and all that goes along with that. I'll stay tuned.

 

[pepindavid]

Wow, the sensor is only accurate to +\- 3 degrees C?

Not sure where that comes from, as their site says:

Q. How accurate is the Brewometer?

A. The specific gravity is accurate +/- 0.002.The thermometer is accurate +/- 2 degrees F (+/- 1 degree C).

 

[303Dan]

Keep in mind the electronics were not made by Brewometer. My guess is they buy the board off the shelf. The temp swings must either be a faulty temperature sensor or the math they use to perform calculations. The probability of a several faulty sensors should be very low, so I believe something else is going on there.

Also, the published temp accuracy for the temp sensor is +/- 3 degs C.

Not sure where that comes from, as their site says:

Q. How accurate is the Brewometer?

A. The specific gravity is accurate +/- 0.002.The thermometer is accurate +/- 2 degrees F (+/- 1 degree C).

I was assuming BrunDog was quoting stated specifications from the manufacturer of the temperature sensor component itself.

 

[BrunDog]

Well, the temp accuracy according to Punch Through is +/- 3: https://punchthrough.com/bean/guides/features/temperature/

But, accuracy and repeatability are two different things. The former assumes no calibration, the latter includes it. My guess is because we can calibrate, the resulting accuracy is much higher. So don't sweat this number too much.

 

[user 204491]

Interesting that the Bean site says they use the BMA250 chip which is designed to measure air temperature, not liquid temperature.

Would it be a logical conclusion therefore that they are not directly measuring the temp of the liquid that the unit floats in, but are instead measuring the temp of the air inside the Brewometer's protective casing?

That could explain why my new units seemed to be so far off on temp when I calibrated their gravity readings. They both needed adjusting by 6-8 degrees according to my Thermapen readings. Now I wonder if I'd allowed them to acclimate to their environment for 20 minutes or so if they would have gotten closer to the actual liquid temp. I'll try to give that a shot this evening if I have time and see what happens.

I also wonder if that could account for some of the temp swings we're seeing? Part of the unit floats above the surface of the water a bit, and air temperature changes much more rapidly than liquid temperature. I mean I don't think it would account for the +/- 20F swings I was seeing, but still makes me wonder.

 

[HLSheppard]

I've been generally enjoying mine since I put it into service last week. I was in such a hurry to start using it - I didn't bother to calibrate it (shame on me).

I have been noticing that the closer my phone is to the actual unit, the lower the gravity seems to be. Nothing huge, but when I get 20+ feet away the gravity will read 1.012 but as I walk within say, 5 feet it will go to 1.009.

I have been able to reliably repeat this for the last 3 days. I'm not really worried about it - just find it interesting.

Can any of you electronic engineer-types shed any light on this?

 

[beskone]

Interesting that the Bean site says they use the BMA250 chip which is designed to measure air temperature, not liquid temperature.

Would it be a logical conclusion therefore that they are not directly measuring the temp of the liquid that the unit floats in, but are instead measuring the temp of the air inside the Brewometer's protective casing?

Exactly this. The chip / probe are inside the plastic casing, so it's measuring air temp inside the casing which is affected by the temperature of the liquid it's floating in.

So if you pull a brand new one out of a box that's sitting in 85º ambient air, throw it in a 65º carboy and immediately calibrate it for 65º you're gonna have a bad time.

Best to put in in water and let it equalize for at least 30 minutes before calibrating I would guess.

 

[user 204491]

Exactly this. The chip / probe are inside the plastic casing, so it's measuring air temp inside the casing which is affected by the temperature of the liquid it's floating in.

So if you pull a brand new one out of a box that's sitting in 85º ambient air, throw it in a 65º carboy and immediately calibrate it for 65º you're gonna have a bad time.

Best to put in in water and let it equalize for at least 30 minutes before calibrating I would guess.

Yep, I bet that is exactly what's going on. Tonight I will clear my previous calibrations and try again after letting it sit in the water for 30 minutes or so to acclimate.

I do still wonder if this is what is causing the temp anomalies since part of the unit floats above water and it takes time for the air inside the unit to adjust to the temp of the wort.

I never heard back from the developers after Thursday last week, so I'll drop them a note and see what's up.

 

[jpakstis]

I did some fooling around with it/getting acclimated with it over the weekend in anticipation of brewing this weekend and I gathered that the temp is really the air temp inside the casing since I noticed it reacting slower to changes in water temp than my Thermapen's reading, but wasn't too far off (around 3-4 degrees).

 

[CascadeOK]

It would be nice if it used a stainless steel bottom cap with an actual probe on the inside of the SS cap. I'd rather have true liquid temps and it would be a fast calibration and cut down on their temp related customer service issues.

A BrewPi integration for dummies would also boost sales a bit.

 

[Carlscan26]

It would be nice if it used a stainless steel bottom cap with an actual probe on the inside of the SS cap. I'd rather have true liquid temps and it would be a fast calibration and cut down on their temp relates customer service issues.



A BrewPi integration for dummies would also boost sales a bit.

Great points!!

 

[user 204491]

FWIW I did hear back from the developer on measuring air temp as opposed to liquid temp. Here is what they had to say:

You are correct on the temp. The device needs to come to equilibrium to calibrate/test. It takes 15-30 minutes depending. I would clear the temp calibration you made, let it sit in a known temp solution then check again and recalibrate as needed.

 

[pepindavid]

Interesting. Could the difference in temp between the interior of the device, the air in the headspace and the beer somehow affect the way the device is floating, hence affecting the "tilt" and therefore the gravity calculation? That would explain why I was getting some very weird gravity readings during temperature changes (e.g.: while cold crashing).

 

[user 204491]

If you take a look at my tracking graph here, you'll see that I had a number of unexplainable temp readings throughout my fermentation, and with each one the gravity also swung in correlation with the temp. I saw the most craziness going on after I started my cold crash as well.

I pointed this out to the developer, and he said they discussed it at length at their meeting last week, but they could not explain it. He said they received another defective unit like mine, and they will be testing both out to see what could have caused the problem.

I'll be getting my replacement unit in some fermenting beer this weekend and my second unit going next weekend, so I should be able to report soon if this first one was just a complete anomaly, or if there's some sort of larger problem at hand.

So far the folks I've been corresponding with have been very nice, and I'm sold that they will stick to their word and refund or replace any units if people are not satisfied with them.

 

[BrunDog]

I would certainly expect a time lag between the liquid temp change and the sensor reading. But the unit is Amosa completely submerged so I expect the conductivity through the case to be fairly effective. Would be interesting to see how/if cold crashing screws up the readings in the short term.

 

[boat_eggs]

Learn from my mistake and dont chuck one of these in during the sanitize step on a conical. Mine got stuck in the elbow in the bottom Im glad I got a pair, the other one is happy. Once I get a always on tablet Ill pay attention to the gravity/temps swings and compare them to my BCS temp probes.

 

[NeoBrew]

Wouldn't measuring the temp inside the capsule lead to errors from the heat of the electronics in there?

 

[BrunDog]

There is some quiescent heat generated by the electronics but it is too negligible to make any difference. The battery life claim is 3-6 months, so the power being dissipated is practically nothing.

I don't think we should witch-hunt the temp sensor. It is integrated with the accelerometer and is a reasonably quality piece. The question is how they implemented them mathematically.

 

[user 204491]

I would certainly expect a time lag between the liquid temp change and the sensor reading. But the unit is Amosa completely submerged so I expect the conductivity through the case to be fairly effective. Would be interesting to see how/if cold crashing screws up the readings in the short term.

If you take a look at my graph here, the point on 4/24 @ 4:51 AM is when I started my cold crash. You can see that it did not behave very nicely.

It was sitting at 65 when I kicked in the cold crash, and the first thing it did was jump up to 78, then dropped all the way down to 24, and was all of the place for the next 4 days.

Again, this was with my "defective" unit which has been replaced, but I haven't had a chance to try out the new one yet.

I had another exchange with the developer last night, and I asked him about the bit of the Brewometer that was exposed to air, and he told me that in their testing they had not experienced this causing any problems with the temp readings. He also said they are working on a new unit using an IR temp sensor.