Electric Brewery

[Crusader-Rob]

Hi Everyone,

Its on my list of things to do, as I'm setting up a brewshed outthe back. (No I'm not building it, its essentially a garage, that wont fit a car in it, weird.)

anyways, it needs power so i can connect fridge and so on for fermentation, and I've been researching and thinking, that going all electric, would actually make sense, and I could become a bit more automated so to speak, less heavy lifting lugging things outside etc. its all in one place.... the list goes on.

My current setup is as follows:

- 50lt Cooler Mash Tun, fitted with Bazooke Screen
-50lt Stainless Steel Brew Pot, one of the cheaper thinner ones of trademe.
- Immersion Chiller
doing 19-23 litres batches mainly.
I also have a 30lt pot, from the days of partial boil extract as well.

 

So my thoughts were one of a couple of options... a couple of people are using Hot Water urns for E-BIAB, and thought maybe I could use 3 of these 40lt urns and turn them into a single tier 3-vessel system, as the taps apparantly come apart, and I can then fit  thermowells etc. in there and have the ballvalve installed, along with some of the ideas from www.theelectricbrewery.com, for probes and so on mainly.

But then I thought I could possibly make it myself, using the existing items I have:
30lt Pot as HLT
Current mashtun either improve insulation or fit a pump and HERMS through HLT for Mash temp Stability, I think I'd like to do it, as it tends to skip a step for vorlaufing as well and creates ne clear, repeatable beer
and 50lt boil kettle.

All fitted (apart from Mashtun) with Heating Elements, Temperature probes ball valves, and 1-2 pumps, possibly add another bazooka screen to the boil kettle to help filter out the trub?

Can anyone offer any advice, those who have E-Breweries, how does it work for you? what equipment do you have, and would what I'm saying actually work through the Cooler Tun?
If anyone has done anything similar, an idea of what parts. you name it I want the information.

[Chris Banks]

If the PV is not at or close to SV after a period of time the P , I or D settings require tweaking the easiest way to do this is to run or rerun autotune.

If the PV is flickering around the sensor lead could be

a - picking up some interference from a power lead or source (try to keep power and sensor leads separated as far as is practical.

b - a less than 100% connection some where in the sensor lead (cheap plugs are notorious for making poor contact) 

[Sam]

Cheers Chris

Auto tuned and now it finishes at set value. Tried experimenting with separating sensor cable inside enclosure but it still jumps around, its Auber connections so hopefully its reasonable quality and making a good connection, wiggling doesn't make any difference though, was wondering if anyone else has this issue.

Also noticed the tip of the sensor is going black after use and a bit of a bit of rust stain has come from it, also has a slight look like the colour lines stainless can get from heating below tip, not sure why this is happening as its in one of the 4 gaps in the element

[Druid]

I get rust streaks off my Auber HLT temp probe too - haven't got around to disassembling it yet to see exactly which bit is oxidising but I assume its just because its made of inferior grade stainless.

IIRC, they are a one piece unit (apart from the backing nut, but I'm pretty sure it's not the nut that's rusting) so its really only the probe itself that can be rusting.

I now just make sure the HLT is drained, open and dried from its own heat when my brew day is finished.

I wondered whether HLT water additions made a difference to accelerating oxidation too.

[Chris Banks]

Auber plugs have been excellent in my experience.

The discoloration of the sensor tip sounds unusual but probably corrosion related due to poor quality stainless or poorly treated stainless (by the manufacturer) but this is not normally a concern with the Auber gear?

Unless something extraordinary is going on (like a stray current) I doubt the staining is heat related as stainless starts to take on different colored oxides in the 300-600c range which is bloody hot in a ~75c water bath!

Additions of brewing salts especially anything chloride related can accelerate corrosion in areas where the chromium oxide has been damaged and especially if clumps of salt sit in one spot for a period of time they can be quite aggressive.

As Druid says keeping the stainless clean and dry during storage goes a long way.

[Druid]

I'll pull mine apart to have a closer inspection.

I guess a stray current through the probe to the pot could be the cause - especially seeing the HLT is grounded through the element earth.

Can't imagine it being normal galvanic corrosion though unless the pot is of such inferior quality stainless that it qualifies as a dissimilar metal in relation to the probe material - I guess it wouldn't surprise me though...

[Druid]

Just looked at it and there's definitely pitting on the inside of the HLT wall underneath the backing nut. I don't tighten the backing nut up much because it distorts the silicon washer on the outside and it looks like water sits under it and doesn't evaporate. Might put another silicon washer between the backing nut and the HLT wall which should improve the electrical insulation there but it still leaves the gap between the probe thread and the hole. Any thoughts?

EDIT: or should I be electrically bonding the probe body to the pot wall via the element earth?

[Hutch]

Sounds like crevice corrosion (a kind of oxygen concentration cell)! A washer on the inside might reduce your problems.

[Sam]

I'm 95% sure the rusting etc on mine occurred from when the element was on, so could be leakage current jumping to the tip of the sensor, then travelling through it and jumping to the keg at its base through the water I guess, I'm not sure whether bonding the sensor to the keg would lesson the problem or make it worse though (maybe it would help your pitting problem though?). After testing it has been left to cool down for a day before but I wouldn't think there would be enough oxygen to cause any problems when its submerged, I also noticed the colour of sensor looked different through the water during the first test so something was probably already happening in the times it takes to heat the water up. 

[Sam]

Also the colour lines below the rusting have a bit of that rainbow look

[Sam]

Got some good answers and in depth explanations of what's probably going on from auber (the likely cause relating to the manufacturing process), just got to check something with them first but will post what they say either tomorrow or the day after for anyone whos interested

[Benjamin Morehu]

Very interested. The tip of my Auber probe discoloured first time I used it

[Sam]

Yea on mine it started shiney and was discolouring before I even got up to temp!

Sounds like its partly an issue of cost saving and the difficulty level in machining, but once the initial layer of corrosion is removed this can sometimes slow down the future corrosion, so hopefully it won't be as bad after initial cleaning (or if you're unlucky the tip won't really be SS at all anymore due to the welding).

Austenitic stainless steel carbide precipitation

"The rust is from the welding area. Unfortunately, this is the area that it is very difficult to control. We use 304 SS because 316 is much more difficult and costly to machine. I would like to explain what caused the rust. Theoretically, all stainless steel can rust when the condition is right. The stainless steel is a alloy of iron, chrome, nickel. It relies on the chromium oxide formed on the surface to resist corrosion. The alloy is a "solid solution" that all elements are mixed uniformly. That is not very easy to form because each element has different melting point. If the cooling speed of a melted metal pot is not controlled, some of the high melting point element will precipitated out (or crystalized out) first. Then, instead of  a "solution" mixture, it become a crystal mixture of different element. The rust resistance property of the metal will become poor, or even lost. During the production of stainless steel, the cooling speed of the metal is controlled so that the element does not precipitated out. But during the welding, that is difficult to control. The smaller the part is, the more difficult it to control it. This probe has a very thin and small tubing with very little thermal mass. The cooling speed is very difficult to control. Normally, the stain resistance property will become weak after the welding. 

Rust normally accelerate  when there is water,  oxygen (or air) and temperature is warm. If the probe is deep in the cold water, it should be fine. If the  probe is close to the surface of water or in the air with water on it, it will get rusty quicker.  So, after use, you should dry it out.  The rust on the probe seems are only on the surface, you can try to remove them with a Scotch brite.  Some times, the electrochmical active spot is only on the surface (crystal of carbon is the most common). Removing them will slow the corrosion."

Also "The corrosion should become minimal once you removed the first layer"