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A Question For All Biabers Using Urns

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NealK

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From all the info I have found here and on other forums, most people use their urn either on full power or off. So when mashing they insulate the urn to stop heat loss. This is how I did my first 2 brews. I didn't really understand why, when we have an urn that is capable of holding temperature at 64 or 67 (or whatever mash temp you require), not just leave the urn on to hold the correct temp?
This is how I did my last brew and I managed to hit all my targets and my efficiency was also the best it has been so far.
I am using a 3kw 40 litre Birko and it holds temperature really well for mashing. Am I just lucky with my last brew? Or am I missing something that more experienced urn users have had problems with?
Any feedback would be greatly appreciated.
 

RdeVjun

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Simple: Insulation = less work!
I am not a fan of extra, unnecessary effort- I can't see the value in replacing a passive system that works brilliantly with something active that requires a. active heating control and b. mechanical input (to stir the heat through). :huh:
Edit: I don't use an urn however the same argument applies to just about any mashing vessel.
 

hopnerd

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I use a 40L crown and am by no means an expert, but as I understand it there are two issues with heating the urn with the bag immersed:1. The heat comes from the bottom of the urn and without constant stirring it's possible to get uneven heat distribution. 2. The element can be significantly hotter than the water, and may burn the bag if it comes into contact with it.
Personnaly I use a metal strainer to separate the bag from the element, but really haven't needed it. I have only done single infusion mashes to date, and with insulation usually only lose about half a degree. Makes life very easy as I don't have to stir during the mash.
This link is a bloody good read, might try a step mash at some stage using this approach.
 

.DJ.

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I probably loose 1 degree per hour when wrapped in old sleeping bags... so why would I bother leaving it on?
 

JestersDarts

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If there's an element on underneath the mash, you'd need to stir to distribute the temperature evenly throughout.
Also - you need to be wary that the bag isnt touching the element when on, i've read here of people experiencing burnt bag bottoms
Also I wouldnt trust the urns temperature dial to show you the mash temp, i mean your wanting 1 degree accuracy out of that thing.. and the urn just isnt built for that purpose really.
 

Bribie G

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On the occasions I have preheated the strike water (set urn to 68 degrees then go out shopping etc) I've found the urn thermo to be a bit vague and it's been, say, 72 on my return. So I wouldn't rely on the Urn thermo.

Also as posted above you would need to stir often to distribute heat, whilst checking with a probe thermometer, which would get old very quickly.

However step mashing with BIAB in an urn is a breeze , which really sets it apart from most "standard" 3 vessel systems. You are going to have to run the urn to get up to boiling eventually, so stepping the mash comes "for free" with little extra work apart from some stirring and a re-wrap of the insulation.

A cake rack or roasting rack makes it easy, although you need to stand and pump the mash around with a paint stirrer or similar, but only takes a few minutes per step to ramp up from say 63 to 72 - rewrap the urn for half an hour or so, then up to mashout 78 and raise bag whilst continuing to heat to boiling.
 

bcp

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From all the info I have found here and on other forums, most people use their urn either on full power or off. So when mashing they insulate the urn to stop heat loss. This is how I did my first 2 brews. I didn't really understand why, when we have an urn that is capable of holding temperature at 64 or 67 (or whatever mash temp you require), not just leave the urn on to hold the correct temp?
This is how I did my last brew and I managed to hit all my targets and my efficiency was also the best it has been so far.
I am using a 3kw 40 litre Birko and it holds temperature really well for mashing. Am I just lucky with my last brew? Or am I missing something that more experienced urn users have had problems with?
Any feedback would be greatly appreciated.
You'll find with a bag full of grain you'll have very uneven temperature at top and bottom. The heat comes from underneath and can't get to the top very easily.
 

NealK

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I probably loose 1 degree per hour when wrapped in old sleeping bags... so why would I bother leaving it on?
When I insulated I got about the same. I was concerned about the poor efficiency I was getting so I tried keeping it on with the lid off and stirring regularly. To be honest I enjoyed the stirring. Efficiency went from 62% last brew to 76% this one.
 

Bribie G

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Using insulation and a mashout I usually get around 75% which was independently verified by a Nazi with a refractometer at the "systems war" brew session last year in Bris. Interestingly, the ghetto system, the 3v and the Braumeister were almost identical to this as well. Makes me wonder sometimes if the "I get 99.9999 efficiency" posters are having a lend of themselves :p
 

Thirsty Boy

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In all likelyhood, the main reason you got better efficiency was the stirring - add a whack of regular stirring to your mash and your efficiency will go up. Probably it indicates you weren't stirring quite enough on mash in too if there was a "big" jump.

"regular, on target, steady... all that stuff" with regard to temeprature, really should make very little difference to your efficiency. It makes a difference to how your your beer turns , but not really a lot to your efficiency unless your temp is quite low. High temps help, stirring helps, time helps.

If you dont stir at all times (not just occasionally or even regularly) you are adding heat - you run (as everyone above has said) a very real risk of burning your bag, burning your grain, overheating portions of your mash and having no actual idea of the real temperature in the urn... its something you can "get away with" and I have no doubt that there are people out there who have managed to make it work for them on a regular basis, but I strongly suggest that there are better ways to get a more certain result.

Mind you, I think people who say "can't" in homebrewing are generally to be deeply suspected of bullshit - so if its working for you, ignore us and carry on. Just be aware that there are potential issue and watch out for them, and we get to laugh at you if you melt a hole in your bag OK.
 

Bribie G

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The other thing about stirring / pumping the grain up and down is that a lot of the good wort can hide in the husks. A couple of weeks ago I did an overnight mash and the next morning took the wraps off and checked the gravity of the wort out of interest. It was 1010.

After a minor freak out, I pumped with the paint stirrer and checked again - 1040

That's why I always do a mashout , pumping up and down constantly as I ramp up (about 10 mins usually), a tip from TB I took on board a long time ago. I used to live on a bus route and always made sure I wasn't doing it with my back to the street :)
 

NealK

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Thanks for all the replies.
I am going to do my next brew the same as my first. Efficiency was 59%. This brew was stirred at 10, 30 and 60 mins. Very well insulated and lost only 1 degree in 90 mins.
This time I will do exactly the same recipe and the same mash schedule but will mashout and pump with the paint stirrer in a firm but affectionate manner during the temperature change and see what difference it makes.
I do have a colander over the element if I am going to turn the heat on with the bag in the urn.
None of my processes have been perfected yet and all the advice I get is helping me move forward. Thank you to everybody who has posted. I will post the results when I have them.
 

NealK

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okay, I repeated my first brew. (And also checked all my notes!)
First time round it was 5kg of pilsner malt. 2 northdown hop plugs at 45 mins and 2 mittelfreuh plugs in the no chill cube. Mashed for 90 mins and stirred at 15 and 45 mins. Well insulated and lost only 1.5 degrees in 90 mins.
This brew I used 4.5kg of pilsner malt but hops stayed the same. I mashed for 75 mins stirring at 15 and 45 as before. Kept well insulated and lost about 1.5 degrees over 75 mins. At 75 mins I cranked the heat and pumped the paint stirrer for about 10 mins until it hit 76 degrees. Left it for about 5 mins and then stirred for another 5.
Everything else was the same as the first brew.
Efficiency of the first brew was 59%. Efficiency this brew was 75%. I think this will be my mash routine for the next few brews. I will be happy to get 75% efficiency as long as I get consistency.
This first batch was dubbed "Urn Test Pilsner" and was my first full size batch of all grain. (I did a couple of stove top mini biab batches before I bought the urn). It turned out to be a very nice brew indeed and the keg is nearly empty so I am glad to have another batch.
 

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