BeerBug review part 2 – Use and conclusions

UPDATE – This review was done on a prototype BeerBug!  I will have a new review out for the release hardware that is now available for pre-order in a few weeks.  That link will be posted here when I get the review done.

Here are a couple of the differences between the bug reviewed here and the release hardware:

Component Prototype Release
Communication Bluetooth WiFi
Battery 1 AA, replaceable Internal rechargable via micro-USB
SG Sensor Old “beam” sensor New “blade” sensor




A note as we get started.  Please remember that the version of the BeerBug I am using is not the final retail version.  This is an early build so it’s very likely improvements will be made before it’s released.  Also, the final BeerBug will use WiFi connectivity, mine is a Bluetooth version.

If you haven’t seen part 1 of the review here’s a link.


With fermentation under way the primary reason to measure specific gravity is to see how fermentation is progressing and to determine when it has finished.

So how did the BeerBug fare in accomplishing these tasks, and how did it compare to using a hydrometer to do so?

First of all let’s talk about something I skipped over last time, setting it up initially.  ParasitX provides good instructions for doing this on their website.  I did have a bit of trouble at first, but I was trying to do it differently from what the instructions show.  I had been using the bluetooth software that came with my adapter rather than the built in software.  I decided to uninstall that software and use the default software as shown in the instructions instead.  Once I did that everything worked perfectly.

Also related to connecting to the bug is my setup.  I ferment inside a chest freezer in my office/brewery/guest room’s closet.  So the BeerBug was sitting inside a closed chest freezer connecting to a PC with a USB bluetooth adapter about 15 feet away.  I have had no problems connecting in this setup.


It happens that I would like to keg this batch as soon as possible.  Usually I just wait 3 or 4 weeks and then take two readings a day apart to make sure the gravity is no longer changing before kegging but in this case I wanted to rush things along a bit.  With a hydrometer that would mean taking a reading once a day after a few days had gone by until the gravity was no longer changing.

For each reading I would need to sanitize something to take a sample with, open my fermenter, take a sample, measure it, and record the measurement.


With the BeerBug we still need to take readings until they are no longer changing.  However it’s quite a bit simpler to do so.  I press the button on top of the bug, open the software on my computer, click connect, and click “All Data”.  At that point I am presented with a nice graph showing the specific gravity plotted every 10 minutes from the time I started the brew until now.

This has a couple advantages over the hydrometer.  First, it’s less work to take a reading and if taking daily readings to determine the end of fermentation this can save a lot of work over the course of fermentation.  Second, each time you open the fermenter you risk introducing infection, a problem that the BeerBug eliminates.

Chocolate Milk Stout   Data View

Now, as you may have noticed the graph above contains a few problems.

  1. The first data point shows an SG of 1.018
  2. There is a jump in the SG on 7/28 around 2am.
  3. The SG ends up at about 0.982.

I am fairly certain that number 1 occured because I started my brew before moving the bucket into my freezer, so that reading was likely taken while my bug was sloshing around as I moved it.

Number 2 is more of a mystery.  I asked ParasitX about it and they said that they have seen occasional jumps in SG, but usually smaller than mine (almost a 0.01 jump) and almost always directly correlated to temperature change.

Number 3 is the biggest issue.  The OG reading (after the 1.018 thing) was about right, which leads me to believe that the bug was correctly calibrated when this brew started off.  Clearly something went wrong along the way.  When fermentation was done I took the bug and put it in a bucket of water to see what it would tell me the SG of water was, 0.952 apparently.  So I tared it and it went through the process as usual and then gave me… 0.960?  I tried restarting the software and re-taring, same result.  Then I tried rebooting the bug by taking the battery out and putting it back in, then re-taring, that did the trick.  The joys of being a beta tester.  🙂

Tare Water   Raw data

That was my first brew using the BeerBug!  Here are the impressions I came away with.

Ease of Use – Excellent

I had no problem getting the BeerBug set up, calibrated and taking readings in my brew.

Software – Very Good

The PC software is pretty well designed and works well for what it’s supposed to do.  You get nice graphs and can interact with them in an intuitive and useful way.  You can also export the data to an XML file, load previously saved files, and connect to as many BeerBugs as you want (I think, couldn’t test that part).

Connectivity – Good

The actual connection between the BeerBug and my PC was excellent.  It had no trouble communicating through my closed chest freezer.  This only gets a “Good” because it isn’t a more “always on” connection.  I would love to be able to remotely check my SG while away from home, but since I have to press a button on the BeerBug to wake up its bluetooth radio that isn’t possible.

Data Provided – Okay

I would describe the data acquired during this brew as useful, but not reliable.  The reason being that even if the SG reading wasn’t accurate, it did show me when the SG had stopped changing, which told me when fermentation was complete without having to crack open the fermenter.  However since the FG was showing at below 1.000 I was certain the reading was wrong and had to take a hydrometer reading to get the real FG.  Because of this I will continue to take hydrometer FG readings even when the BeerBug FG is believable.  It’s possible this will prove to be unnecessary in the future, but for now it seems like the best thing to do.

Hardware – Very Good

The hardware is well designed with the needs of the brewer in mind.  It will fit into any fermenter, and if you need the torpedo to hang at a different length you can just tie a different line to it of the appropriate length.  It also comes with an attachment for a blowoff tube for those bigger beers.

I found the device easy to clean, using a q-tip for the inside and wiping down with a sponge on the outside.


I like the BeerBug, it saves me work figuring out when fermentation is done, it makes cool graphs, and I can access the data directly via the API so I can tinker with it however I want.

I hope that as the people at ParasitX continue to work on it the things I was not impressed with can be fixed.  If they do create a device that can send a constant stream of accurate data I will go from liking this thing to loving it.



According to a Kickstarter update released by ParasitX the WiFi version of the BeerBug (aka first retail version) will have several significant improvements over the device I’ve just finished reviewing.  They have addressed my biggest gripe (no always-on connection), saved me the work of creating a way to get my data online, and it sounds like they’ve made the SG readings more reliable too.  If all that holds up I may well end up loving this thing!

Here is the list from the update:

  • An all new SG sensor design (which we’ll hear more about once a patent is filed)
  • LCD for quick SG and Temp readings
  • Micro-USB rechargeable Lithium-Ion battery
  • 3 quick input buttons for power, calibration and readings
  • 2 LEDs for power, signal and data feedback
  • 1 photodiode for fast WiFi network blink-up

Also, apparently they are “building out to house all of our user’s data and recipes along with real-time updates and global sharing capabilities.”

Read the full update here. 


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