Using An Urn For Brew In A Bag - Tutorial

[Bribie G]

I was chatting with Cocko who said I'm making a rod for my own back because I keep posting the same information and should write a guide to brewing in a bag specifically for electric urn users. Good call, article follows (about ten minutes from now, just gotta upload some pics so hang in). Maybe mods might like to airlock it in the newbie AG Partial thread here if that might be of use to new or prospective AG brewers? I didn't do it as a proper article because I believe they don't support the inclusion of pictures?

 

[Bribie G]

A Basic Guide to Brew in a Bag (BIAB) using an Urn​

​

For a comprehensive guide to BIAB, see the thread airlocked in the All Grain forum. However here's a summary of BIAB in an urn so we know what we are going to cover in this current article. This article is in two sections, a general discussion followed by a 'how to'.

Between 30 and 35 litres of water (liquor) is heated to strike temperature which is around 2 to 3 degrees hotter than the desired mash temperature.

• The power is turned off. A bag large enough to completely fill the urn is fitted and secured around the top of the urn.
• The grain bill is quickly and thoroughly stirred in and the urn covered.
• The urn is lagged using sleeping bags or a doonah or camping mat and left for the desired mash period (some brewers prefer to add heat during the mash, this will be covered later).
• The lagging is removed, the bag is hoisted and drained, power turned back on and the wort brought to the boil.
• A hop sock is suspended in the wort and hop additions are made.
• Kettle finings may be added towards the end of the boil.
• The hop sock is raised, the urn is covered and allowed to boil just long enough to sterilise the headspace without getting a boilover, and power is switched off.
• The wort / break is allowed to settle and the wort is run off either through a chiller or into a cube for no-chilling.

General Discussion​

40L electric urns are becoming increasingly popular, as they lend themselves to Brew in a Bag (BIAB). The popularity of BIAB derives largely from its being a 'one pot' method with no need to buy and operate three separate vessels with associated plumbing and in many cases March pumps etc.

Many BIAB brewers have taken this concept one stage further by using an electric urn, thus doing away with the need to buy gas bottles and burners or the need to drill or modify a large stockpot or a keggle. Add a brewing bag and the 40L urn is virtually a 'turn-key' brewery ready to go out of the box.


Disadvantages of an urn.

Brews are limited to single-size 'standard' 23 to 25 litre batches. Not having done a poll on this, I nevertheless get the impression that brewers doing large double or even triple batches are in the minority and urns would not suit their style of brewing. On the other hand the ease of use of an urn for BIAB brewing make it quite feasable to do a side by side brew using two urns, or even do two end-to-end brews on one day with not much more effort than a large three vessel brew with its attendant clean up and sanitising chores.

Any disadvantages of doing BIAB in a 40 litre pot in general also apply to urns, for example a 25 litre brew of extremely strong beer such as a Russian Imperial Stout would not be a serious candidate for this style of brewing. However for most brewers who prefer their beer between 3.5 % and 6% ABV they should have few efficiency problems.

Urns, reportedly, take longer to heat to strike temperature than gas and longer to raise the wort to a rolling boil compared to gas. Having said that many 3 vessel brewers actually use an urn as a Hot Liquor Tun. Some brewers use a time switch to turn on a pre-filled urn so the strike liquor is ready at a prearranged time.

Getting an Urn

There are two main brands of urn available in Australia, Birko and Crown. Costing between $250 and $320 depending on deals and suppliers. (August 2009). Crown urns are available from the AHB sponsor CraftBrewer (no affilliation) within that price range. I have a Birko that I bought from a catering equipment firm. Birko urns have an exposed element, Crown Urns have a concealed element in the base. There has been some criticism that Crown urns have a thermostat cut off which makes the boil sluggish. This can be worked around but I don't offer any advice on this, not being a qualified electrician. Birko urns give a good rolling boil.
Some brewers on the forum have had luck getting a cheap urn on Ebay.

Getting a Bag

Swiss Voile is the most popular material, it's a thin light polyester curtain material available from Spotlight, about $15 for enough material to make a bag. I get the impression that Birko urns are a bit shorter and wider than Crown urns so I won't offer exact measurements, but the best design is exactly like a can of baked beans with a circular bottom section. This will hang like a teardrop on hoisting. A pillowcase or sling design whilst possibly stronger and more durable in the long run has the disadvantage that when it is hoisted it looks like a pair of dogs family jewels and the two lobes are almost guaranteed to dribble down the outside of the urn.
If you are a long way from a fabric shop and don't have a sewing machine or know a sewing person then mail order is the way to go. Gryphon Brewing sell premade BIAB bags (no affilliation except that I bought one recently and can recommend) and CraftBrewer have started to stock Swiss Voile material as well.

Hoisting the Bag

A skyhook is welcome, I just use a single pulley which is a cheap awning pulley with a fairly thick cord to avoid it slipping off the wheel and jamming.



On hoisting, the cord can be tied off and the bag left to drip at its own pace while the wort is raised to the boil. If no skyhook then raise manually and squeeze, then drain into a nappy bucket hanging off a doorknob. I have even hung mine off the freezer door of my dead fridge. I won't beat around the bush here .. hoisting and draining is the unpleasant aspect of BIAB, probably as much a PITA as having to scoop kilos of spent grain out of a mash tun and clean it and the braid, no free lunches. Unfortunately Bunnings etc don't seem to stock light double pulley tackle for some reason but some BIAB brewers may have ideas on a double pulley design.

Urn care



The Birko element can be scrubbed nice and clean using a green kitchen scourer. Surprisingly sugars and other compounds don't get 'burned on' to it and after a few brews it may take on a chalky appearance but that scrubs off easily. An urn descaler/cleaner is available from Catering suppliers but I haven't used it yet, it's more for urns that have been used in catering and left on for days on end with town water in them I guess. It is very important to take the tap apart when cleaning. The Birko tap comes apart safely and easily. Crown owners please edit here accordingly. Many owners easily replace the native tap with a ball lock tap. I'll be doing that, haven't got round to it.

Familiarity can breed contempt and always be aware that you are dealing with electric equipment containing nearly 40L of boiling liquid that could easily put you in hospital or kill pets and small children so the same safety precautions should be taken as with all brewing operations.

Step by step how to​

Of course this section contains a lot of information that is common to all brewing, and a lot that is common to all BIAB brewing. I'm just presenting how I do things on my equipment using a Birko Urn.

Thread your cord through the skyhook if you have one. Nothing worse than forgetting and having to clamber over a full hot urn later on.

Prepare the strike liquor

It is essential that you have a good thermometer, an electronic probe kitchen style thermometer is ideal for mashing. I don't fiddle with the temperature knob on the urn, I just leave the Birko on 95 full time. I'm fortunate to have solar hot water and carry 5 litre jerry cans to fill urn to about 35 litres. This leaves plenty of leeway for grain bills up to 5.5k.
While the urn is heating I add any water salts and weigh out the grain bill. I don't personally mill but this would be the ideal time to mill your grain. As a rule of thumb I allow three degrees hotter strike water. So if I'm aiming for a mash at 66 I will heat the strike liquor to 69 but allow it to just "come off" after that for a few minutes. Give the liquor a good stir so you aren't measuring the temperature of a convection plume.

Fit the bag

Switch off the power, lower the bag and clip it round the edges of the urn with clothes pegs. The Gryphon bags are elasticated.

Dough in

Add the grain bill in a thin stream and stir constantly with a large spoon to avoid doughballs. Then give the mash a good up and down rousing with a metal paint stirrer or a good stir with whatever other mash paddle you have on hand.



Cover and lag

If your bag has a drawstring, close it up tight, lid on and slip an old kids sized sleeping bag over the urn like a giant condom. Be careful of the urn tap which you can flick on accidentally. Then wrap the whole thing in a doonah and strap it with some cord. You should get about one degree per hour drop in temperature, which is more than acceptable as most saccharification will take place in the first half hour. Many BIABers have their urn permanently lagged with cut-up camping mat but still wrap in extra insulation while mashing.




Some BIABers do a half - time application of heat. With a Crown this should not be a problem, with a Birko you could raise the bag clear of the element and apply a short burst. In both cases you would need to open the urn and do a big stir up to distribute the heat. Personally I wouldn't bother but may do an experiment sometime.

I normally do 90 min mashes, and have a cheap timer set to 90 mins.

Hoist the bag

Before hoisting, I usually give the mash another good pumping with the paint stirrer to loosen it up and flush out any goodies that may be hiding in the grain husks. If you can get an assistant to grasp the bag in two hands, lift it clear of the wort and keep it there while you tie off the pulley rope, you've won.
Otherwise you will need to hold and squeeze until the bag is light enough to put it in a nappy bucket or small baby bath and hang it off a door knob, tripod, whatever you can find. For tying off the rope, a wall mounted cleat is a brilliant one-hand solution.

A tweak: sparge in a bucket

At this stage you could just bring the wort to the boil and tip the grain. However there's still malty goodness in there and I regularly do a sparge in a nappy bucket with five or six litres of very hot liquor prepared in the kitchen. In the photo it's hanging off the freezer door of the dead fridge as mentioned previously.



Now we are going for a rolling boil,



note the hopsock ready to lower and also note that this level of wort in a Birko boiled for 90 minutes on a roll should reduce to enough wort to fill a 20L cube (actually 23 litres) plus up to three extra litres which I put into sterilised jars and add to the fermenter with the cube. I haven't done an exact calibration except to say that when they call it a 40L urn that's what it is, 40L no more and no less.

At the end of the boil

Don't forget the Whirlfloc. When finished, remove hopsock and put the lid on the urn then move quickly to the wall socket and keep an eye on the urn, you will see some plumes of steam shooting out of the nostrils on the lid. Then switch off before the wort rises and foams out from under the lid. This should have nicely sanitised the headspace so you can safely leave it for about twenty minutes by which time the break and shyte will have settled right out.

BIAB's work is done.

Equipment check list.



Depending on which methods you use, you may not need all the items lower down in the list. I have not gone into No-chill equipment, which is not part of BIAB although a popular method, except to say that whatever cooling method you use, replacing the urn tap with a ball lock tap will enable you to fit a silicone hose which is difficult to do with the 'native' urn taps.

Urn
Extension Cord
Bag
Mash Paddle and spoons
Accurate 'stick' thermometer
Scales accurate to 1g
If using a skyhook: Awning rope, pulley
If passive lagging: Sleeping bag, doonah
Nappy bucket
Stockpot

This should get you brewing grain beers and set yourself free for less than $400 (excluding fermentation side gear), less if you shop around and no doubt you will have many of these items already if you are already doing kits or extract brewing.

Happy Brewing

BribieG August 2009

 

[reviled]

Nice work mate, well written :icon_cheers:

 

[Pollux]

Good write up....

Notes I shall add as a Crown user.

1. The tap can be unscrewed, it may feel tight out of the box, but once it gets a dose of boiling liquid run through it's quite easy to undo.
2. The Crown does have issues in terms of heating and also holding a significant boil. I have performed the modification whereby I bypassed the "boil dry" switch. This has allowed the crown to reach it's strike/mashout/boil temps alot faster.
3. I am in the group of people who have used a camping/yoga mat as permanent insulation (although I do remove it to wash the urn). My advice is to avoid the mats that look like one giant piece of foam, as these tend to melt to the sides of the urn. I suck at being able to describe the style of mat, I shall take some photos tomorrow.


Great write up there Michael, about time someone did an urn guide.

 

[Carboy]

Hi BribieG,

Awesome work :super: , your post will certainly help me when I move to AG in an urn in a few weeks.

Cheers
Carboy :icon_cheers:

 

[Nick JD]

Awesome!

 

[pdilley]

You go Michael!

Love your work. Would feel no worries over handing that writeup to any new brewer looking for advice

Cheers,
Brewer Pete

 

[thylacine]

Thanks for the step by step w/pics. Canberra currently has 40l Birkos for $266. I'll be refering to your suggestions in the near future.

I notice that you didn't include (or I missed it...) your current procedure re 'mash-out'. eg. 78c (I've read some of your previous threads/comments re mash-out)
Have you replaced it this 'tutorial' with your description of 'sparge in a bucket'?

Thanks again. You are always a positive voice...

Cheers

 

[Bribie G]

I was hesitating about adding the 'mashout' because you can't really do a mashout and a sparge in the bucket in the same BIAB brew because you would end up swimming in extra wort. I thought for the time being I would just include the sparge in a bucket to keep the discussion simple. Really I still don't know which one would result in better efficiency but I'm tending to the sparge in a bucket. :icon_cheers:

 

[brando]

I also use the 40L Birko for BIAB brewing.

I've used a Kmart $10 camping mat and it melted onto the urn at contact points. No good.

I use the light duty silicon hose from Craftbrewer, and attach it straight onto the "native" tap. It's a bit of a bugger to get on first time, but softens up over time, and I would recommend it.

My "bag" is just a 2 meter diameter round piece of Swiss Voile that Craftwbrewer also sells (although not advertised on the website). I can't see the benefit in screwing around sewing together a proper bag. Just overlock the edges to prevent any fraying.

Soaking in Napisan works ok to clean the element, but not great. Perhaps PBW would be better - anyone comment on this?

 

[altone]

Good onya BribieG

Nice little tutorial.
I'm going to try an electric urn BIAB next weekend (although mines only 30 litres so might aim for
18-20l of final wort)
As others posted, I've bypassed the boildry sensor to improve boil time - obviously this cannot be recommended.
Gives all the basic info for electric urn 1 pot BIAB so far as I can see (in conjunction with the main BIAB link obviously)

Nice job

 

[Thirsty Boy]

Thanks for that Michael - I will be pointing people to this thread

 

[loikar]

Please Wiki this!

 

[RdeVjun]

Wow, what a top job, BribieG! This is something that's been in the back of my mind for a while, albeit from the dreaded stockpot angle, but this covers everything brilliantly and just tears the fork out. Absolutely no hesitation on my behalf in recommending this as a well thought out, pictorial and practical guide. :super:

+1 for the bucket sparge tweak, it is a must- do for me, else make a small beer with the spent grain, but that's another OT story.

I don't even have a single question. Oh wait, yeah I do, but this one's for the Mods- what's the hold up in Airlocking this? :angry:

 

[Macca17]

Fantastic writeup, haven't done an AG brew yet, still getting the bits together,but that answered
all my questions I still had

 

[Gulf]

To clean the element (including concealed element plate), fill the urn with 50% vinegar solution until the element is covered. Turn on the urn and boil for five minutes. Leave to cool (preferably overnight) and then empty the urn. Any remaining scale can be removed easily by wiping. Rinse the urn with clean water, bringing to the boil if desired.

 

[brando]

To clean the element (including concealed element plate), fill the urn with 50% vinegar solution until the element is covered. Turn on the urn and boil for five minutes. Leave to cool (preferably overnight) and then empty the urn. Any remaining scale can be removed easily by wiping. Rinse the urn with clean water, bringing to the boil if desired.

Good one! I'll try that.

 

[crundle]

Well done Bribie! I was thinking of doing a tutorial but you beat me to it, and a great tutorial you have written too!

Concerning the camping mats, I have one around mine that comes off for cleaning, and have only found that it sticks to the body of the urn when it gets wort spilled between the mat and the body of the urn. The water evaporates leaving behind the sugar like a glue. If this happens, wet the outside of the urn to dissolve the sugar and the mat will come off with no bits left stuck to the urn. The camping mats really do help with faster heating and better maintaining of a boil, and add an extra layer of insulation while mashing.

Regarding the Crown urn modification to make it boil harder/heat up quicker, here is the link for those that wish to give it a go - Crown urn modification It is a simple mod, but it does remove the anti boil-dry protection the Crown offers, so that must be kept in mind when using the urn after the mod.

Once again a great tutorial Bribie, well done!

cheers,

Crundle

 

[Bubba Q]

Brilliant guide. The only things that differ in my brew day are I lift the bag and squeeze by hand, then sparge by placing the bag on a rack from a roasting tray over a bucket, and instead of using a doona for insulation I have a camping mat and flip over a collapsible bunnings cooler to cover the urn. Works great.

 

[bowie in space]

Well Done Bribie! :icon_cheers: Perfect timing for me as I have just priced a 40L Birko urn through Hotel Agencies in Fitzroy for $265, and i'll be ordering a bag from gryphon with free postage for $43. So for just over $300, i'll be AG'ing in no time. I love it when birthdays are just around the corner.

This tutorial is the icing on the cake too :beer:
Cheers
Bowie