Got Me An Urn!

[bignath]

Hi all,

i have acquired myself an urn which has a capacity of 30lt. I have been reading some awesome info on BIAB using an urn. I am just starting to get into mashing/steeping grains with a view to go to all grain brewing once i am comfortable with the processes.

i have a few questions re: BIAB and urns.

Just wondering if someone can check my thoughts on using an urn in this way.

Is a 30lt urn enough capacity to finish up with 20lt of wort into fermenter? I am kegging so after gravity samples only need 19lt. Not brewing anything overly heavy, pales ales and lagers.
Also if sparging is not a requirement for the BIAB method, is there anything wrong with calculating evaporation and other losses, adding that figure onto 20lt to get my kettle volume, steeping grains in that volume, then bring to boil and follow hop schedule and other adjuncts etc. Then cool with my chiller, into fermenter and pitch?

Lastly, if i have been steeping grains, adding hops to smaller pots 5-6litres and then topping up fermenter, Does my quantity of grains stay the same if i can use the urn as described and mash/steep in the full volume required? or do i need to have a different quantity of grains. Not sure if the overall effect of the grains in a smaller volume mash + fermenter top up is equal to simply using same quantity in a bigger vessel.

Hope these questions make sense.

Cheers for any help guys!

BigNath

 

[boobiedazzler]

I am using a 40 litre urn, that gets filled with 32 litres of water, then the bag goes in which raises the tide to almost the rim. After the bag is removed, it takes a few litres of water with it. Then the boil evaporates a few more litres, and finally the trub at the bottom that gets left behind. I end up just filling a 20 litre cube (which is about 23 litres). So Im thinking that you might be pushing it to do a full batch BIAB in a 30 litre urn. You could always top it up with more water through the boil, and add a little bit of DME to bring the OG up. While this wont make it a 100% AG beer, at least 3/4 will be with grain.

 

[Thirsty Boy]

Boobie has it - 30L is almost certainly too small for straight up BIAB - in your situation you will most likely have to use an alternative method.

There are a few around - and when there was a rash of 30L urns on e-bay I wrote a tutorial on how to BIAB in one. This is how I'd do it... but there are plenty of variations that would work.

View attachment Smaller_Urn_2V_BIAB.doc

This method is designed to keep you out of the kitchen and avoid the need for extra pots of water to heat - all your heat energy comes from your urn. Its a kludge, but it works perfectly well.

TB

PS - Nath - What you describe is exactly how you work out how much water you need.

 

[mxd]

there's an article, written by thirsty, that talks about how to do a full batch with a 30 ltr urn, you need to do a sparge, i.e pull bag out, put it into "bucket" and pour 6 ?? ltrs of 76Deg water over it then dunk and squeeze, then put that wort back into the urn and then start your boil. You possibly only want up to 26 ltrs or wort in the urn when you start you boil, then you'll possibly make 20 ltrs to the fermenter.

Good luck and welcome to the dark side.

 

[MarkBastard]

Yeah, just do a dunk sparge in a bucket. The annoying thing will be getting the 6 or so litres of water for sparging up to temperature, but you can do that on the stove of course.

I believe some people would use the urn to make up say 28 litres of water to strike temps, then draw off 6 litres into a smaller pot and put on the stove on a low flame, just enough to keep the heat.

 

[bignath]

Awesome. Thanks for clearing that up everyone! Makes perfect sense. I will have a go at heating my water in the urn to strike, drawing off 6lt to a pot (which i already have), keep that warm, put more cold water into urn therefore bringing it back down closer to mashing/steeping temp at around 26 or so litres and boil boil boil.....

what about quantity of grains versus doing a small boil on the stove? Same/similar amount i'm thinking as either way it will end up at same finished quantity? Eg: does it matter that the grains on the stovetop method are being mashed/steeped in a smaller quantity of water and then diluted when it gets topped up at the fermenter, and does this have the same "profile" when same quantity of grains mashed in more of a finished (full) volume at the start and not get topped up?

Sorry for all the questions, that was the last one and then i think i have all the info i need to start AG/BIABing. Can't wait!

Cheers,

BigNath

 

[mxd]

I'm a little confused about what you asked ?

but give this a shot http://www.aussiehomebrewer.com/forum//ind...&recipe=502, it's a common first beer.

but I think it would be something like this (n.b I don't do a mash out)

N.B usual disclaimer I'm a noob

put 30 ltrs of water in urn,

get to 68 degrees.

pour 8 ltrs out into a pot,

Add 2 ltrs water to urn

Heat urn to 68 deg

put bag in urn

put grain in bag

mash (temp should be around 65)

wrap urn up
leave for 1 hour or so.

pull bag up, give a squeeze,

Turn urn on.

Place bag in bucket, pour 8 ltrs of water over bag,

Dunk and squeeze, etc..

Pour bucket into urn,

Hopefully around the 27ish ltr mark.

When boil starts, hot break etc..

Start you hop additions and 60 minute timesr.

 

[Bribie G]

Nothing I can add to the above except to echo that if you get yourself a good cheap stockpot (the 15 Litre ones are always on special at two dollar stores quite cheap) and draw some hot water out of the urn first and reserve it by keeping it on a low heat in the kitchen, or even get a little $30 electric benchtop ring from ALDI next time they come up so you can keep all your processing in one spot - then you can mash strong and do a sparge, and should end up with enough after the boil to fill a 20L cube.

 

[MarkBastard]

Some of the volumes seem a bit off to me but everyones setup is different.

I have a 40L urn and I start with about 29 litres of water at strike temp, which is usually about 69 degrees.

I put my bag in and then put my grain in, which is about 4.7kg of grain to make about a 5% alcohol beer.

After the mash, and squeezing and draining the bag, and the getting it up to the boil, I probably have about 27 litres of hot wort.

This boils down to about 23 litres. I leave about 1L of trub behind in the kettle, so I cube about 22L.

When I transfer the cube to the fermenter the next day, I end up only tipping about 20L into the fermenter with about 500ml of crap left in the cube. Where did the other 1.5L go you might ask? When liquid cools it shrinks.

So you have a 30 minute urn. All things being the same as mine, you'll want to start with 27L of hot wort at the start of your boil. I'm assuming this is okay in a 30L urn but you'll learn whether that's correct or not pretty quickly ;-)

However you get that 27L is up to you. I currently have 2L of loss to grain or thereabouts so if you're similar, you'll want to be using 27L of hot water in total across your brew. So you can start with 27L, draw off 6L and then you should not have to add any cold water etc as far as I can tell.

Your first brew will be a test of course, to know what levels to use.

 

[boobiedazzler]

[quote post='641085' date='Jun 9 2010, 09:00 AM']what about quantity of grains versus doing a small boil on the stove?[/quote]

Traditional wort production uses way less water/grain ratios for the mash than single vessel BIAB, and then makes up for it in the sparging process.