Crown Urn: volume undershot by 6L

[shacked]

No I float a circle of bubble wrap on top of mash, wrap in sleeping bag plus metallised foam rubber (Clarks Rubber) sheet and just walk away for an hour or more. Then I pump mash up and down with paint stirrer thing and switch element back on to raise to mashout.

Thanks mate.

I feel a trip to Clark Rubber is in order. I'll spend the holidays trying to tune in my urn and drinking beer [of course]!

 

[shacked]

Hi shacked, my urn is insulated and it takes just under 40 min to get to boil from the mash

What did you use for insulation?

 

[bigmacthepunker]

Hi shacked, I pinched my wifey thick yoga mat for insulation. Eaton laser have urn measuring sticks to measure how much in the kettle. Very handy or a $25 spend. I measure the boil off live just to see that I'm on target.

 

[ianh]

Hi shacked

I think your initial measurement of water may be one problem. If you look at my spreadsheet BIAB Beer Designer pinned to this forum it is set up for using a Crown 40 L urn. You measure the water volume by measuring the depth using a steel rule, You measure again at start and end of boil. This way you can work out where the waters going.

On my set up, I use a factor of 0.45 for grain absorption and 3.5 L/hr for evaporation during boil. With 4 L trub loss using your recipe I would start with 35 litres of water.

 

[shacked]

Thanks Ian, love your spreadsheets!

I'm going to get a stainless ruler or equivalent. I'll just need to adjust because I have a drop in strainer from National Homebrew (HBHB ) over the concealed element.

Cheers!!

 

[ianh]

If you measure the water level then drop in the strainer then remeasure you can make allowance for the strainer. Fortunately I am set up with a pulley system so don't need to cover the element, just raise the bag.

cheers

 

[Bribie G]

Bump:

Here's a Crown urn just now with 35L water plus 7 kg of grain.

Let's see how much is left after I raise the bag and drain, and how it boils up.



It also raises the interesting point that 35L of water plus 7kg of grain doesn't necessarily mean 42L of mash.

 

[Bribie G]

After an hour's boil, waiting for a better break but this should fill three 10L no-chill cubes for a double batch. The other "cube" is actually a Coopers Lager kit I need to use up.

No problems with boilovers etc.

 

[Pedro6]

Yeah it was the first time I've used it and it's brand new. I think maybe the lack of insulation and being outside may have impacted the time to bring to boil.

How long does it take you from the end of your mash?

First time I used Crown Urn was also out side and it took for ever to boil but inside it only took 34 minutes to reach boil.
Also for the first few times, I had lid off to check temperature so that probably did not help either.
Are you sure full 240 volts are reaching unit as an extension cord or old wiring in house could have some effect as well?

cheers

 

[shacked]

Today I had another crack at BIAB on the urn. 5.5kg of grain (mostly Maris with a touch of rye and caramunich) and was aiming for a SG of 1.051 and 22L in the cube.

According to Brew Mate I needed 33.5L to mash with a pre-boil gravity of 1.047 and 29.9L. I ended up with 31.5L and 1.036. In order to compensate for the additional volume and low gravity I extended the boil by 30 mins. At 30 mins I was down to 30 odd litres and I put my 60 m hop addition in and continued on.

I ended up with 22L in the cube and 3.8L of trub. I undershot the SG by 0.05

Am I right to assume I've lost about 400ml per kg of grain? I boiled off 5.5L in 90 mins being 3.7L per hour or about 11.5%?

Finally, my efficiency is crap. Any suggestions for improving my mash? I have insulated with foil backed foam and a sleeping bag. I lost 1.9 degrees in 60 mins. At 30 mins I checked the temp (lost a degree), gave it a stir and picked the bag up and moved it around.

Cheers!!

 

[BobtheBrewer]

Am I right to assume I've lost about 400ml per kg of grain? I boiled off 5.5L in 90 mins being 3.7L per hour or about 11.5%?

That is a good boil off percentage, I don't understand your statement "At 30 mins I was down to 30 odd litres and I put my 60 min hop addition in and continued on." The 60 min addition should go in 60 mins before the end of the boil, not 60 mins after the start of the boil. Can you post the brewmate page so that we can check it out?

 

[shacked]

That is a good boil off percentage, I don't understand your statement "At 30 mins I was down to 30 odd litres and I put my 60 min hop addition in and continued on." The 60 min addition should go in 60 mins before the end of the boil, not 60 mins after the start of the boil. Can you post the brewmate page so that we can check it out?

Hey Bob,

Sorry but I wasn't clear. I'd originally planned a 60 minute boil but because I undershot my SG and overshot my volume I decided to extend the boil length. I've calibrated my urn for volume, so I set the wort to boil and waited until it got to my target volume for my original boil; this took 30 minutes. After that 30 minute period I added my 60 minute hops and continued to boil for a further 60 minutes for a 90 minute boil in total. Added the rest of the hops to the cube.

Cheers!!

Edit: Brew Mate brew day screen added

 

[Mr B]

I am fairly new to AG so still dialling in, i THINK that a few minutes of stirring on mash in and mash out helped pick up my efficiency.

I also have moved to 90 min mashes - this may also have helped. Not sure which may have had a bigger influence, or if it was something else entirely.........

Could be worth a try - I initially thought dough balls were actual balls but the term may relate to the small particles of grain not being in full contact with the wort.

Couple of sick kids, might do a bit of reading on it.

Edit (and 7 spews later) - Nope, dough balls appear to be actual clumps of grain. There goes that theory....possibly.......hmmmm.......

 

[stux]

How do you know that you had 5.5Kg of grain?

 

[shacked]

How do you know that you had 5.5Kg of grain?

I ordered it from the LHBS and assumed they'd be on the mark. I didn't re-weigh it to be honest...

 

[stux]

I ordered it from the LHBS and assumed they'd be on the mark. I didn't re-weigh it to be honest...

Worth checking it

If it was under, you'd have less points of gravity and more volume, because of less loss to absorption