KegLand RAPT Pill - Hands On Review

We've been anxiously awaiting the release (and stock availability) of the new RAPT Pill from KegLand.  After finally getting our hands on one, here's our thoughts and experience with it so far.

The RAPT Pill is a Wi-Fi and Bluetooth capable hydrometer and thermometer. Targeted at the homebrewing market, it enables brewers to view the real-time temperature and specific gravity of their brew by being (partially) submerged in the fermentation vessel during active fermentation. It then utilises Wi-Fi connectivity (by connecting it to your home Wi-Fi network) to report the temperature and gravity readings back to the RAPT Portal where it can be viewed in a graph showing real time and historical data. The gravity is calculated by accelerometers that measure the lean angle of the Pill that will change as the specific gravity of the wort does. Pretty clever, right?

Although the idea isn’t unique - there are existing products on the market already that do exactly this - like the iSpindel or Tilt hydrometer, KegLand are aiming to differentiate their product in two ways. Price and ease of use - or being completely ‘plug and play’. 

Having a digital hydrometer to monitor your fermentation negates the need for regular hydrometer readings - something we've never particularly liked due to the waste factor - although relatively minor, who likes to waste beer?

KegLand RAPT Pill - Hydrometer/Thermometer

The packaging for the Pill is minimal - coming in a simple plastic case with a small leaflet. The leaflet itself contains two QR codes that direct to the RAPT Pill item on the KegLand website, and the RAPT Portal. The link to the RAPT Portal is certainly a good idea, but the other QR code pointing to the KegLand website would be much better served directing to the Quick Start Guide for the Pill, which is concise and well written and covers everything - such as installing the battery, LED indicator meanings, how to connect the Pill to Wi-Fi, firmware updates, calibration etc.

The Pill is charged by a standard USB-C connection, which surprisingly isn't included in the box. We used a MacBook charger which worked well, but if you don't have one of these, any USB-C cable connected to either a computer or AC adapter will work. The higher the wattage, the faster the Pill will charge. Presumably not including a charging cable is a simple cost saving, and/or manufacturing simplifying idea, though consumers could reasonably expect just about any electronic device to come with a charging cable included in this day and age. There also isn't any mention of the fact a charging cable isn't included on the Pill item page of the KegLand website which would no doubt catch some customers out and be a little frustrating. No one likes receiving a new gadget and not being able to use it.

The RAPT Pill comes with a leaflet with a couple of QR codes

Unpacking the Pill and we're a little surprised at how heavy it is. Most of this weight would be attributed to the single battery inside. The plastic is super smooth as you'd expect, and feels really solid/sturdy. Unlike other digital hydrometers on the market, the Pill unscrews from the middle, and the screw threads are completely hidden when assembled, with a rubber gasket ensuring the threads remain moisture free, followed by another gasket on the other end of the thread to ensure no moisture gets further inside the unit where the circuit board is located. The completely smooth exterior helps with cleaning and sanitation, with no exposed nooks or crannies for bacteria or other nasties to hide within which is vital considering the Pill will be floating and in direct contact with whatever is in your fermenter.

First order of business is to unscrew the Pill so we can connect it for initial charging. The Quick Start Guide mentions an initial charge of 24 hours is often required - as this helps the device calibrate what 100% charge state looks like as a 'baseline'. It's also worth pointing out that there are some small blue strips of plastic that need to be removed from both battery terminals. These are in place to prevent the battery from becoming completely depleted during shipping. We removed it from one terminal without realising there was another strip on the other terminal of the battery as well which delayed our initial use since the battery wasn't actually able to charge properly.

Note the blue plastic strip between the battery and the terminal - there's one of these on both ends of the battery!

After connecting the Pill to a power source via USB-C, a flashing green and solid red light will appear. Flashing green indicates the captive portal (used to access and configure the Pill) is active, and the solid red light indicates the battery is charging. If the device isn't accessed after 15 minutes, the captive portal becomes unavailable (to preserve battery life) and the green light flashing stops.

When connected to a USB-C cable, you'll see a flashing green and solid red light

We decided to wait until the initial charge was completed before accessing and setting up the device. In order to make the Wi-Fi captive portal available again once charing is completed, the Pill needs to be unplugged, then plugged back in. The only time you're able to access the device for configuring it is when it is connected via USB-C and is indicated by the green flashing light (as mentioned previously).

We did the configuration from an iPhone, but this can of course be done from any mobile device with Wi-Fi, or a regular computer/mac device.

The captive portal is very quick to become available when the Pill is plugged in - we noticed an SSID named "KegLand RAPT Hydrometer" appeared - so we selected that one. This was unexpected as the quick start guide states the SSID should be called "Rapt Pill xxxx". We joined the "KegLand RAPT Hydrometer" network anyway, which prompted for a password which is  kegland1. As soon as the network is joined, the captive portal page opened right up where you can access and configure the device. We noticed a short time later the "Rapt Pill xxxx" network was available however, but for our setup the KegLand RAPT Hydrometer network was the one we used.

The first page that appears in the portal allows you to select a Wi-Fi network to connect to (as detected by the Pill). This worked really well and was completely painless - after selecting our network and entering the password, it was joined immediately and gave a nice clear Success page indicating so. For tech savvy users, once the Pill is joined to your Wi-Fi network, you are able to access it using the IP address assigned to it on your Wi-Fi rather than joining the Wi-Fi network broadcast by the Pill itself - something we found useful and a little easier than changing over Wi-Fi networks on our phone. Interestingly, it appears with the device name "espressif" on our local network.

Once conected to Wi-Fi. we could then access the 'Registration' section of the Pill interface where we are presented with the devices MAC address and User Code - a unique code to use to securely add your Pill to your RAPT Portal account.

RAPT Pill Registration Page

Therefore, the next thing to do was to register an account on the RAPT Portal - again, totally painless, and also has the ability to integrate with Facebook or Google accounts to simplify the process which is great.

Once logged into the RAPT Portal, we could easily add the device using the menu at the top - and after entering the devices MAC address and User Code that we previously determined, the Pill was added to our account, although interestingly the terminology is not consistent between the interfaces. The Pill interface (pictured above) specifies a "User Code", and the RAPT Portal asks for a "Validation Code". In any case, they are the same thing, but after registering is where our problems began.

Adding the Pill to our RAPT Portal account

The portal accepted the MAC address and User/Validation Code information, and the Pill was displayed in the portal, however, it would not receive or display any data. Logging into the Pill web interface, we were able to access some of the details from the Diagnostics page including the ability to 'Send Telemetry Now'. When we selected this option, or the option to download a firmware update, we were presented with a banner at the top of the screen reading "No internet connection". Weird, as the device is definitely joined to the Wi-Fi - we could see it in our list of devices from our modem/router. Subsequent attempts gave a different error - "Can't submit telemetry - device is not registered". Once again, weird, since the Pill is registered in the RAPT portal.

Telemetry data would not submit after our first registration attempt

We managed to resolve the problem by removing the Pill from our Portal, then generating a new user code from the Pill registration page, and re-adding it in the RAPT Portal. This time it all worked successfully - well, nearly all worked.

Confirmation our (second) registration was successful

The Registration page within the Pill interface now showed the device as successfully registered, which it didn't do before, and telemetry was submitting successfully. The problem we now had was the battery status was showing 0% in the RAPT portal, and was showing "N/A" from the Pill Diagnostics page. We decided to press on anyway since seeing the battery charge percentage wasn't the biggest of problems at the moment.

Battery status showing as N/A

To test how our Pill worked, we filled our FermZilla All Rounder with several litres of cold tap water. We made sure the Pill was screwed together all the way so both rubber ring gaskets were covered/sealed. Speaking of which, a fair amount of torque is required to get it done up all the way - probably a good thing as it's important the seal is good/tight, as water leaking in would certainly be detrimental to all the electronics inside, but may prove problematic for those with poor hand/wrist strength.

Before putting the Pill into the FermZilla, we kicked off a standard calibration from the web interface which gave some really good/clear instructions to disconnect and put the Pill into water. Once the readings stabilised as much as possible, and we were sure it wasn't resting up against the side of the Fermenter, we hit the calibrate button which then set the current tilt angle to gravity 1.000. Easy.

There are other options as well to do different types of calibrations. The advanced calibration method requires a second sample fluid with a known gravity which would be useful for those who require very high levels of accuracy. For most though, a standard calibration with regular water will suffice and provide reasonably accurate results.

The calibration feature is intuitive and easy to complete

Our next test was to put the FermZilla (with the Pill inside) into our dedicated fermentation fridge. The fridge is located in the garage, which is only just across the hallway from where our Wi-Fi modem/access point is, but fridges have been known to significantly impede on wireless signals so we wanted to make sure it was going to work. Thankfully with the FermZilla inside the fridge, we were getting a really strong Wi-Fi signal from the Pill which meant there should be no issues when we use it in a brew.

Next we wanted to see how the readings fared with the FermZilla full of room temperature tap water in the fridge. As the fridge was fully operational, overnight the temperature steadily dropped from 26C all the way down to 7C. And along with the temperature drop, the gravity readings also plummeted from 1.000 down to 0.995. We were a little surprised to see this happen, as we know that temperature of a fluid affects it's specific gravity - this is why regular hydrometers are calibrated at a certain temperature, usually 20C and have an adjustment chart/schedule to use if the sample you are testing is not at this temperature. Sure, the differences aren't that great, but we're hoping that temperature adjustment/compensation could be added to the Pill software in the future to address this.

Submerged in water only and chilled from 26C to 7C - there was a gravity drop of 5 points.
(Red line shows temperature, blue line shows gravity)

There is perhaps an argument however that such a large temperature drop - almost 20C would never occur under regular or ideal fermentation conditions - only during a cold crash, at which point fermentation would be completed. It could potentially catch people out though who may not realise and/or fully understand the process, or may go by the FG reading from the Pill after the cold crash, which could potentially be several points lower than it should be and result in a higher than actual ABV calculation.

Lastly, we wanted to fix the issue with the battery status showing 0% in the RAPT portal, and N/A status in the Pill interface. The final solution to this problem was to re-connect the Pill to a USB-C cable to let it fully charge again (so the red light was no longer illuminated). After submitting telemetry again once the Pill had been fully charged, we now had the battery status reading correctly. We suspect that the initial charge being done before we registered and setup the device in the Portal may have had something to do with this problem, perhaps a bug? But it was easy enough to fix in the end, and other reports from the RAPT Users Facebook group indicates this is perhaps the case.

Battery status issue was fixed by completing another full charge

In terms of battery life, KegLand expect that the battery should last approximately 6 months on a full charge - if you leave the default telemetry interval of 60 minutes. Such a long life span between charges is achieved by the clever way the Pill works. When it is not connected to a USB-C cable, it essentially goes into a 'sleep' mode. If it is kept in a horizontal position - ie. when being stored and not used, it remains in this sleep mode and is essentially off. If it is in any position other than horizontal, and is therefore presumably being used, it remains in this sleep mode, and then periodically 'wakes up', connects to the Wi-Fi, submits it's reading/data to the RAPT Portal, then goes back to sleep. The frequency that this happens is determined by the telemetry interval which can be adjusted from within the Pill web interface. We changed ours from 60 to 30 (minutes). The lower the value, the more frequently the Pill will report/send its data but the shorter the battery will last before requiring charging.

The Telemetry interval can be adjusted from within the Pill web interface

Overall, our experience with the RAPT Pill so far has been mixed, but we'd say largely positive. Let's not forget the product is still very new, only being released a few months ago in late 2021. We know KegLand are actively working on improving the product - with both firmware updates and updates to the Portal interface as well. There appear to be a couple of small bugs that need to be ironed out with the registration process and battery status not displaying correctly initially - feedback in the RAPT Users Facebook group suggests that several users have experienced similar problems. We'd also like to see improvements with temperature compensation and the Portal interface, which is good, but could use some more 'polish' for lack of a better word to improve usability and user-friendliness. A mobile app would also be a really useful addition. The process for connecting to and setting up the Pill is quite good - it's simple and intuitive, however, a QR code directly to the well written Getting Started Guide should really be included.

At the current price point of AU$69.95, it's definitely worth considering. Especially when comparing to alternative options on the market such as the Tilt Hydrometer, which generally retails for more than double the current cost of the RAPT Pill, or the iSpindel which is open source and generally requires assembly and more configuration (like integration with a Raspberry Pi) to get going. KegLand are definitely on the right track with the Pill - it sure has plenty of potential to be brilliant. The RAPT ecosystem KegLand are developing is looking particularly exciting. Imagine your RAPT Pill being configured to a RAPT temperature controller that your fermentation fridge is plugged into. When the Pill reaches the expected terminal gravity for your brew, it could then automatically trigger the fridge to run and begin cold crashing without any intervention. This sort of automation is what KegLand appear to be working towards, and the possibilities are almost endless on what could be achieved once a few more RAPT integrated products are available.

The RAPT API has also been made publicly available recently, meaning 3rd party products and integrations with the RAPT Pill are likely not too far away. Think integration with software applications such as Brewfather to automatically submit hydrometer readings to batches within the app.

After our first real brew with the Rapt Pill we found it to work incredibly well, with the final gravity reading from the Pill matching exactly with the reading from our regular hydrometer (1.010).

If you're looking for an alternative to the RAPT Pill, check out our review of the Hydrom which is also a WiFi & Bluetooth enabled digital hydrometer.

Update 27/6/22 - Bluetooth functionality has just been enabled on the RAPT Pill in the latest firmware update released by KegLand. Read up more about how this works on our latest blog post; KegLand RAPT Pill Update - Bluetooth Functionality Enabled

Update 17/8/22 - Check out our review of the KegLand RAPT Temperature Controller to see how it tightly integrates with the RAPT Pill to provide accurate temperature control for your fermentations.

Update 24/8/22 - We have just published a guide on How to Connect the RAPT Pill to the RAPT Temperature Controller via Bluetooth.

Update 27/9/22 - Take a look at our guide on how to connect your RAPT Pill or RAPT Temperature Controller to Brewfather to integrate fermentation logging to batches in Brewfather.

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