Fix For Crown Urn Boiling Issues

[crundle]

@ Pollux - were these brews after the modification, or haven't you made the modification yet? I have noticed that before the mod the boils were a tad inconsistent also, perhaps the darker the beer the more vigorous the boil? If you measured the volumes to be noticeably different, it would make for an interesting experiment. Perhaps a hypothesis might be that darker liquids absorb more heat and hence boil more vigorously? Nothing to back that up of course, but I might pay more attention in future to the evaporation rate, assuming that I can remove other factors as much as possible, such as variance in wind speed outside when brewing, which should affect the evaporation rate.

@ EK - I would say that as the urn is designed to heat water only and not keep it at a constant rolling boil for its intended purpose, that the switch to stop it boiling too hard is fairly sensitive and is factory set to avoid excess evaporation rates. The water itself can only reach its boiling point, and no further till the liquid has completely evaporated, so it can only reach around 100-103 (whatever the boiling point of the wort is).

So the temperature may get to 103 maximum, then switch off and get below 100, probably not a drop of 10 degrees.

As for the day you brewed in the breeze, did you use a camping mat around the outside of the urn to help it stop loss of heat through the sidewall? The breeze should help with evaporation, but also will cool the urn if it is not insulated. Evaporation - Wikipedia This is of interest as a fan or similar can make for much faster evaporation, as will boiling outside depending on the humidity in the air. If the humidity is high (around 90%) then the air has much less ability to remove water vapour from the air than if the humidity was 20%

My understanding is that a rolling boil is required to remove certain undesirables from the wort and helps in removing DMS. A less vigorous boil will not do as good a job of removing these undesirables, which will be more noticeable in lagers (DMS especially). Others may be able to fill in more technical details, but I have read and understood that a vigorous boil is a good thing.

cheers,

Crundle

 

[Pollux]

Both post mod, same conditions, same camping mat insulation.....

Although, I did just think of something, the more vigorous boil was done in the afternoon......Maybe the ambient made enough of a difference??

 

[crundle]

Both post mod, same conditions, same camping mat insulation.....

Although, I did just think of something, the more vigorous boil was done in the afternoon......Maybe the ambient made enough of a difference??

It might be a factor I guess, if the 2400W element is working at the edge of its capacity to keep 30+ litres of wort (not water) on the boil, then a higher ambient temperature would mean less effort is being expended to counter the cooling effect of the ambient temperature.

Wort should have a higher boiling point to begin with, and as the water evaporates and the wort increases in gravity the boiling point should move a bit higher, countered by less volume to boil.

I know that prior to the mod, I was fine brewing in warmer weather, but in winter it became almost impossible to get enough evaporation outside in my usual 90 minutes. Since I started using a camping mat around the outside of the urn it improved, and was assisted by using an immersion element also, but now with the mod I only use the immersion element to cut down my heating times as using both at the beginning of the boil will lead to boil overs.

Crundle

 

[JonnyAnchovy]

I've just done the most stupid/dangerous thing ever.

I've had a 40L crown for few months now, and have done over 6 perfect brews in it. Never had to do the mod - always achieved a strong rolling boil with no issues.

Today I'm brewing a trad bock, and for the first time the boil-dry protection issue kept happening - I had 27L of near-boiling wort in the kettle, and no way of achieving a rolling boil - then I remembered this thread.

Here's where the stupid part comes in...... While balancing the urn, full of scalding hot wort on the side of my table I performed the mod one-handed, squatting directly under the urn. It worked, and its now on a nice vigorous boil, but in retrospect one slip would have been disastrous.

Basically I just want to recommend that NO ONE EVER DO THIS. If you need to do the mod, don't ever risk it with a full kettle - I'm still kicking myself over just how idiotic I was to attempt it. so fkkn happy nothing bad happened.

 

[LethalCorpse]

You did remember to unplug it first, at lest, didn't you?

Did you forget the brewday rule? Don't start drinking until you make the first hop addition.

 

[JonnyAnchovy]

You did remember to unplug it first, at lest, didn't you?

Did you forget the brewday rule? Don't start drinking until you make the first hop addition.

Did unplug, so at least I wouldn't get both 3rd degree burns and electrocuted. Sad thing is I haven't had a single drink today - what does that say about my sober intelligence?

 

[crundle]

Whoa!

Um, yeah, I did mine while it was empty and unplugged, and sober. Glad to see you didn't suffer any adverse effects, but wow, you should put up a printout of that post of yours before you ever do any mods again!

Aye Carumba!!!

Crundle

 

[bullsneck]

Just did the mod, very easy.

Unusual brew today. It's my third on the urn, absolute shite boil (if you could call it that). No problems before that however.

Just modded it, testing a boil now.

 

[lastdrinks]

First boil after the mod and it is night and day. Maybe not a massive rolling boil but compared to before fantastic.

 

[crundle]

Excellent stuff lastdrinks!

I agree it is not the most amazing boil (I think the Birko has better because it has an exposed element), but it is certainly a great improvement over the standard Crown 'boil'.

Great to hear it went well, and hope it improves your brewdays.

cheers,

Crundle

 

[leiothrix]

WARNING

I modded my crown urn 10 brews ago. Got a reasonable boil out of it and was happy.

On Saturday I did two back-to-back. For the second boil I noticed it was a bit pathetic, and figured maybe it was just due to the cooler weather and that I should get a camping mat to insulate.

Bit later I realised that the element was switching on and off, which it shouldn't do as the boil-dry protection was removed and the thermostat was set to 110*C.

Then I noticed the burning plastic smell.

The good news is that the beer will be ok. I got ~26L instead of the 24L that I was expecting, but I'm sure it will still be good.

Bad news is that the urn cooked itself.

You can see the temperature switch at the bottom of the pic. It was not electrically connected at all, but you can see the insulation on the crimp connectors is nice and black. The active leads in the middle of the element are the same. You can also see the neutral leads on the element discolouring, and a bit of discolouration on the right-most active on the thermostat.

I'm guessing that the element is not rated for continuous use, and relied on the temperature switch to stop it from killing itself. That or I'm just unlucky and the element has failed on its own. Either way the temperature switch would have shut it down.

Obviously this could potentially have caused fire, electrical shock, and worst of all loss of beer.

At the moment I'm thinking of drilling a hole in the back and adding one of these. Open to any other options though.

(And Ross -- I don't suppose that there's any chance of a warranty claim? It was only modified slightly )

Rob.

 

[Pollux]

Wow, that is impressive.....


On the topic of Crown mods, I broke my sight tube the other day, removed the fitting today to get the last bit of tube out.......Now tempted to use the existing hole to mount a thermowell for when I build my full rig and the urn becomes a HLT alone.....

Comments?

 

[leiothrix]

Personally I like the site tube on the urn. I've marked mine off in 5L increments with permanent marker, so it's nice and easy to tell how much water is in it. Depending on what your pouring the water into (e.g. an esky) it will also make it easy to see how much to fill it by.

Craftbrewer have replacement tubes for $10 if you want to replace it (here).

Rob.

 

[Pollux]

I'm aware of the replacements, just considering options.....

Might go back to a sight glass for now, at $10 you can't go wrong.

 

[goldstar]

I also have to report my 40 litre Crown urn went pop yesterday. I've done 15 brews with mine without the boil-dry protection switch in the circuit.

I noticed the power light coming on as per normal but the temperature on my PID controller was decreasing over time. There was a slightly funky smell that I hoped wasn't from my mashing weizen grain bill.
I haven't looked underneath as yet but I suspect I will find something similar to leiothrix. For my money, the thermostat isn't rated for a continuous 10A passing through it and has cooked itself.

Assuming the heating element hasn't crapped itself, I intend to remove the thermostat from the circuit and wire up my PID controller directly to it. I'd left the thermostat in there previously for convenience.

If the element is dead, I'll be going to Tobin.
http://www.tobins.com.au/HTML/ClassHTML/175.htm

See item HU032 (4379CR - 2400W Crown Urn element). Just need to check this is definitely the right element for the urn.
I also found out yesterday that K-Mart sell cheap 15 litre pots. Got there in the end!

 

[MarkBastard]

goldstar please keep us updated.

I have done the bypass but mine is still working. I'm thinking maybe I should connect the boil dry back up. I never did do a batch without the modification.

 

[leiothrix]

I think that perhaps the whole lot is not rated for continuous operation. The wires under the element (including those on the not connect boil dry protector) were all burnt black and nasty.

One of the wires on the thermostat was also starting to discolour. If the thermostat was the problem I'd expect for all of the burnt wires to be around it rather than the element.

I'm going to get a S/S sheathed element, drill a hole in the back of the urn and use that. I'll rip the guts out of the bottom too.

I don't think the urns are made for boiling beer. If I had my time again I'd get the element & temp controller that I'm planning to get along with a 50L S/S pot from allquip. The pot is cheaper and larger than the urn at $215 too.

 

[thesunsettree]

I think that perhaps the whole lot is not rated for continuous operation. The wires under the element (including those on the not connect boil dry protector) were all burnt black and nasty.

One of the wires on the thermostat was also starting to discolour. If the thermostat was the problem I'd expect for all of the burnt wires to be around it rather than the element.

I'm going to get a S/S sheathed element, drill a hole in the back of the urn and use that. I'll rip the guts out of the bottom too.

I don't think the urns are made for boiling beer. If I had my time again I'd get the element & temp controller that I'm planning to get along with a 50L S/S pot from allquip. The pot is cheaper and larger than the urn at $215 too.

hi mate,

having used them (ss urn) how would u rate them as a hlt (ie without wort boil??)

cheers
matt

 

[leiothrix]

As a HLT I reckon it would be fine. The main issue though is the temperature set by the thermostat is only a rough guess. It is fairly close though.

What I did was set it to 70* and put it on a timer. In the morning I'd have a pot of hot water waiting for me. I'd measure the temperature with a glass thermometer, and roughly speaking, for every 1* it's over my target strike temperature I'd draw off 1L water and replace it with 1L tap water. Give a bit of a stir and measure the temp again.

Or you could set the thermostat to full and control it with a PID or something.

CB has the 40L Crown urn for $274. Allquip has a 50L S/S pot for $215 (or $85 for aluminium) +$60 for an element gets you more or less the same thing.


I'm thinking that overall a pot is better though. Gives you more flexibility in that you can put holes where you want them. (Or I could be just a bit pissed off due to stuffing it up and having to replace bits).

Rob.

 

[thesunsettree]

As a HLT I reckon it would be fine. The main issue though is the temperature set by the thermostat is only a rough guess. It is fairly close though.

What I did was set it to 70* and put it on a timer. In the morning I'd have a pot of hot water waiting for me. I'd measure the temperature with a glass thermometer, and roughly speaking, for every 1* it's over my target strike temperature I'd draw off 1L water and replace it with 1L tap water. Give a bit of a stir and measure the temp again.

Or you could set the thermostat to full and control it with a PID or something.

CB has the 40L Crown urn for $274. Allquip has a 50L S/S pot for $215 (or $85 for aluminium) +$60 for an element gets you more or less the same thing.


I'm thinking that overall a pot is better though. Gives you more flexibility in that you can put holes where you want them. (Or I could be just a bit pissed off due to stuffing it up and having to replace bits).

Rob.

cheers rob,]

i guess for a hlt it matters not a lot if its aluminium, vs cost saving..

cheers
matt