Here are some starting notes about how AutoBrew is put together. Part 1 is a list of the major components and where they can be sourced.
Now that the machine side of the code has been published, here are some notes about how AutoBrew actually functions.
I plan to follow these notes up with some basic design and build documentation, including:
- a document onf ‘brewing with AutoBrew’ with photos of the machine
- a wiring diagram
- notes on parts and sourcing items
- design notes, including balancing liquor levels to help if you wish to design your own machine
While AutoBrew has been working for quite some time, that is not the same thing as working the way I think it should.
After using it for some time, it was time to redact the code – move it from spaghetti bits and gaffer tape to something revised from the ground up. I’m pleased to say that is done, and I’m happy to release a good working code base for the machine itself.
Get the Photon code here
Release Candidate 1 (github)
This code is for the photon only. It is currently all that is needed to run the machine automatically. A corresponding web app will be more elegant and easier to use, but the tooling from Particle still means that brewing is easy.
The particle console has a log page that shows published events. AutoBrew publishes machine status in the following format:
$T575 0s, Idle#
Txxx – temperature in degrees x10
[xxx] – target temperature in degrees x10
xxxs – clock time in seconds
program step [Idle, Mash1-5, Boil]
The line above shows that the machine temperature is 57.5 degrees and that the machine has no recipe running.
This is available for ios and Android. I currently use this to control the machine.
The photon code has full notes for the control section.
To send a brewing recipe and then brew is simple.
First, send the recipe details:
The ‘R’ tells the machine this is a recipe.
650,0; – is the infusion step. Target is 65.0 degrees with no delay before starting.
640,60;760,1;0,0;0,0;0,0; – are five possible mash steps. Only two are used in this recipe.
- Mash at 64.0 deg for 60 minutes
- Mash at 76.0 deg for 1 minute
60;20,0,0, – are boil time and hop addition times. Boil is 60 minutes. Additions:
- 20 minutes
- 0 minutes
- 0 minutes
(Note: any unused hop addition has a time of 0)
Once the recipe is loaded, send the ‘r’ command to brew. A second ‘r’ will stop brewing.
That is pretty much all there is to it. I’ve simplified the machine since its first iteration. It no longer has a whirlpooling function and this has simplified controls and cleaning. I will update build details when I get the chance.
This machine reliably brews automatically without intervention between loading ingredients and starting, to the time wort is ready. I do not chill, so I fill a ‘cube’ at the end. A chiller could easily be added so wort could be transferred directly to a fermenter.
Web App status
I did have a running web app using an earlier version of photon code. This was an ugly hack and I wasn’t happy with it. I’m currently learning to code with Angular 2 and will use Firebase as a backend to store recipes.
The following sway was something I recorded as part of the process of refining the hop dropper design. It isn’t complete but gives an insight into how I went about it.
I’ve put some notes together on the process of testing and improving the machine prototype. I’m nearly ready to settle on a final working design …
AutoBrew is a delight to use. It has now done four test brews and other than keeping a close eye on a new machine, it is truly hands free and simple to set up and clean.
As a prototype there are a few areas to address before the project is complete.
- improve function and simplify hop dropper
- the current dropper is oversized and the cups don’t mate well enough with the carousel surface.
- a smaller dropper driven by a servo will be more reliable and easier to maintain
- a dropper that fits into half the diameter of the mash tun top allows for a central chute and vent pipe to be installed. This improves appearance of the machine and possibly will improve liquor flow in the mash tun and therefore efficiency of the mash.
- the machine can be made more compact by having the hop dropper completely fit within the mash vessel
- improve mashing efficiency
- currently around 60%
- top down flow is too quick and channels without fully damping some parts of the mash
- test bottom up flow and float the mash
- improve mechanical connections
- multi-purpose chute to have a better mating system to mash tun
- hop dropper to mate to top of chute
- have two part top cover to allow dropper to remain in place while mash is inspected.
- start delay is not functioning
- there is a bug to fix at end of hop drops – the carousel continues to drop rather than park
- level markings
- The pipe that supplies liquor to the mash done is ideal for some ruler markings showing how much liquor is in the kettle.
Ease of use:
This is way ahead of any machine I’ve used to date. Set up and clean up is at most half an hour. The rest is completely hands free. AutoBrew even sends an email at various points to remind me I’m brewing.
Once the prototype is working with greater reliability and efficiency, the project will be documented for hackster.io. I’m reasonably happy with the photon code, but the web app could do with a complete rewrite. It is ok to release as a functional starting point.
The machine is now a Photon away from its inaugural test run.
The image with the notes shows the guts of AutoBrew. The red notes follow the plumbing. Liquor primes the pump and will flow back into the kettle in a whirlpool motion, or via the other outlet to top flood the mash tun. A ball valve is opened at the end of boil to fill a no-chill cube (or a fermenter if desired). There is a concealed heating element in the centre of the vessel. On the underside it looks like a ceramic spiral that is partly visible under the pump, ball valve, and some plumbing.
The kettle has two possible liquor flows depending on ball valve position. Mash liquor is pumped to the head of the mash tun via the straight pipe in the image at left. This is fabricated from copper to accept a Blichmann quick connector. John Blichmann assures me they are good inside a boiling kettle.
The other outlet returns liquor into the kettle in a gentle whirlpooling motion.
The image at left is inside the kettle. At 2 o’clock is the inlet for the pump. At 3:15 is the temperature probe. At 8 o’clock with the whirlpool return, and at 10 o’clock is the line extending upwards to the mash tun.
The image above is of the inside of the mash tun. This rests on top of the kettle. At 5 o’clock the mash liquor line rises up from the kettle. This continues upwards and then floods the top of the mash.
At the bottom of this vessel is a manifold (the ladder shape) with slots cut on the underside. Manifolds are often used in picnic cooler mash tuns. It does the same job as a false bottom. Liquor that flows into the manifold returns to the kettle via a drain at 1 o’clock.
At 1 o’clock there is a cylinder that extends most of the way up the mash tun. This serves a number of purposes. It provides a drop chute for hops from the top to enter the kettle. It also serves as a vent for the kettle. As mentioned previously, it also serves as liquor return from mash into kettle.
There are slots in this multi-purpose cylinder towards the top. This acts to prevent liquor overflows in the system. Liquor floods the top of the tun faster than it drains through the grains into the kettle. Any overflow returns via the cylinder to the kettle ensuring the system remains balanced.
On top of the mash tun rests the hop dropper. This is a simple carousel with cups that align step by step with the drop chute. A micro-switch at 3’oclock ensures cup alignment. The cup at 7:30 is closed allowing for a park position. When parked, the kettle no longer vents. This is useful post-boil during whirlpool or chilling stages.
The machine is driven by a Particle Photon wifi connected device. A web interface via smartphone (or other device) allows for recipe storage and automatic brewing.
To brew with AutoBrew, liquor, grains and hops are loaded along with a brewing recipe. Once brewing has started, no intervention is needed until time to fill a no-chill cube.
The machine has been a couple of years from concept to this point in my spare time. It is about a week away from testing although the parts have all gone through proof of concept.
It goes without saying, I’m a happy brewer! Cheers!