The beer robot lives! (my new electric brewery losses its virginity)

[DMAC]

I've been putting together an electric brewery for about 6 months now. Yesterday she had her first run.

The name beer robot comes from my 5 year old daughter who associates the lights and flashing displays with robots. I think its a pretty good application of mechatronics which is what robotics is called these days from what I can tell.

She is made of three 50 litre pots which I got off trade me for about 50 bucks each. The pots look pretty good but started leaking around the base after the welding spuds for the elements were tig welded in. The welding seems to have opened up a joint between the base and the walls (which are a separate piece) due to the thermal expansion during welding. The good news is that one of the  pots self healed during the boil as the wort sealed the hairline gap. Ill probably fix the other one by boiling some wort in it! The mash tun has no such trouble as it was not welded.

The heat exchange coil is made from 10m of 12mm copper tube. It was a piece of piss to bend the copper into the coil shape around a bucket. Doing the tight bends on the ends and getting the compression fittings to seal was a bit more troublesome. In the end I used o-rings and PTFE tape instead of the ring that came with the fitting. The tube on the left is the return/whirlpool for when the water is circulated to keep the temperature in the vessel even. I used another 10m of copper for the immersion chiller.

The photo below shows the welding spud and the camco 2500w element. In the end I couldn't figure out a nice way to do the wiring so I used double walled heat shrink with adhesive to provide some degree of water proofing. The earth wire pops out the back as these elements from America don't have earth terminals. I think this looks improvised but it seems no worse than the crazy epoxy aluminium setup recommended on the electric brewery sight. This heat shrink is apparently rated to 150C so it should hold up to the temperatures it is exposed to. You can see the seam that leaks water in this photo too. In my set up these elements draw about 2.2kw (measured) as the line voltage is a bit low (220v).

Here's the control panel. It runs from two lines hence two power meters. The HLT and kettle each have two elements on running off each line. Using the switches I can power both elements in each vessel or one in each.There's a hole for a timer which I haven't got yet. As you can see the HLT is 66.6C and the mash tun is 65.5 C about halfway into the mash.The 46watt power draw is just the two pumps and control panel losses. The third PID is giving an error because the probe isn't plugged in yet.

The internals are obviously derived from the electric brewery sight but I made a few changes to allow me to run two 10amp power lines. I haven't got round to labelling the various functions because I'm not really sure how to go about it.

This photo shows the power meters reading the line voltages. Power in each was about 2.1kw. The power seems to drop as they water heats up. I verified these by reading with a bench top multimeter so they are correct if on the low side.

When running the pumps circulate about 4litres of wort per minute. The bottle neck in my se tup is the 3/8th hose between the mash tun filter and the tap. I think flow would be higher other wise since everything else is 1/2 inch.

I used keg king pumps which I bought when on a trip to Sydney cause they are cheaper over there. I bought two and somehow managed to get two versions with later being the silver one. Apparently its rated to a higher temperature but they seem to work the same.

In the end it all worked well with only the minor leak. I did have some troubles with the quick disconnects leaking with the most annoying one on the mash tun outlet (air being sucked in)  which may have been because it was under suction? I got them from a few different places and some are tighter than others.

I brewed a copper coloured bitter as the first brew. I was hoping to do a pale ale but my malt order turned up all mixed together which is apparently how its done these days if your request crushed. Its been probably 12 years since I last did an all grain and in those days it used to turn up in individual bags - I'm pretty sure I used to send my hand filled out paper order and cheque to Luke Nicholas back then?!

I have no idea what the SG was since I couldn't find my hydrometer which is kind of ridiculous given all the effort put into temperature control.

Maybe the most interesting thing for others here is the use of the 2500w camco elements:

Camco 2500 watt ULWD

I have found that the power draw is about 9.5 amps for the line voltages I get. The description of ULWD is a down right lie and they are about half the length that they say they are. I calculated it a while ago and came up with roughly 120w per square inch. None the less I didn't get any scorching although I boiled at only 70% power because I was concerned about it and because I had a nice rolling boil at this setting. The nice thing about this compared to my brewing 12 years ago is that I could get the HLT up to temp in 30 or so minutes (nearly full - 45L) so a brew is nice and fast (remembering I have two elements per kettle).

[Barry]

Mean setup! Looks great, ingenious way to get around requiring a 30A feed too, nice work!
Sounds like everything worked as expected?

[Scott H]

Good stuff DMAC Electric FTW!

[DMAC]

Cheers  Barry and Scott. Yeah it went pretty well. It was effortless compared to my bucket based setup when I was at uni.

Some minor issues. The pots leaking. The quick disconnects sucking in air at the outlet from the false bottom in the mash tun. Ill probably plaster it with Vaseline to try isolate the air leak. I was amazed how much thread tape i had to put on some of the fittings which were not sealing like one would expect.

I ended up with less wort than i thought but i did no measuring of the volumes of water at all so may have terminated the sparge early. Was trying not to over extract since i had no way of measuring gravity or pH.

I need a better way of dealing with the trub and a dip tube in the HLT which are my next projects. I guess i should get a timer if only to plug the hole.

[Barry]

I can highly recommend the Auber beer timer, super easy to use and actually really useful right there on the panel. Even more useful than I thought it would be.

I hear you on the thread tape, my water pump had a leak on the outlet and I tried every number of winds — started with 6, tried 5, 4, 3, 7, 8, 9, all trying to balance the amount of teflon with getting the ball valve tight and straight. Then I spoke to a guy at a stainless fittings shop about whether he had heard of food-safe loctite and he said just keep trying with the teflon tape, even 12 or 15 winds. Tried 12 and it finally sealed with no leaks.

Can also recommend etching your pots with litre marks, that was another thing I was really glad I spent the time to do. Both of my pots came out slightly differently so I know neither of them are absolutely accurate (which really tests my OCD tendencies) but even with 1-2 litres is far better than guesswork.

My remaining thing to fix is trub/hop filtering, the bazooka screen on my kettle outlet was a resounding failure. Going to try without it, but I fear a hop spider is the only reasonable fix.

Brewing tomorrow, and drinking a pint of batch one. So damn nice.

[Brett Mason]

Thanks for the write up, particularly the warning about the elements since I've been thinking about a dual 10a system too.

[DMAC]

Yeah those elements are a bit of a let down from the watt density point of view but its hard to find alternatives. There are some local sources which are considerably more expensive but with a nice low watt density. I have no plans to change them out. I might do the boiling sugar syrup experiment to see if I get caramelisation since there seems to be some dispute over whether wort scorching exists.

[DMAC]

Just finished my second brew. Larger grain bill but flow seemed higher during mash.

Wort coming out of the heat exchanger was basically identical to the HLT temp. Mash temp was again 1 degree lower than the HLT. I think this indicates that the heat exchanger (10m of copper) is working well enough and that flow and heat going out of the mash tun walls is the limitation.

At the start of the boil I transferred about half the wort to the HLT to fix the seeping pot seem. I had one element running in the HLT and one running in the kettle at this point. 2.1kW could keep a slow boil going in each though it wasnt what id call a rolling boil. It worked, the wort sealed the seem but I will wait and see whether it lasts.

I improvised a whirl pool in the kettle by just chucking a hose in the kettle on the side. This wasnt too effective but it bought down the cooling time quite a bit.

[Craig Howard]

Nice job on gear  build.  A great DIY project.

BTW - I hope you have everything well earthed.

[DMAC]

Cheers Craig.

I have got everything earthed but dont like the way i did the earthing on the elements. trying to come up with beter was to do it but havent succeded.

I'll use this as an excuss for an update: Got a new brew table made up. made form pine 4x8s that i riped down. i made the top and shelf heights ajustable in case i want to use it as a work table.

I finished it with cetol varnish which was donated by a boaty (who else would would have a $100 750ml tin of varnish to spare)

need to set up an extractor fan and add something to mount the control panel on...

[Craig Howard]

need to set up an extractor fan and add something to mount the control panel on...

A man after my own heart.  Sounds like you do a bit of "designing" on the fly as well.  Thats the bit I really enjoy.

That bench will look even better than it does now...once it takes on the patina of use over time.