AG#28 - Imperial Stout (Exceeding the Mechanical Limit!)

[WishboneBrewery]

AG#28 - Imperial Stout (Exceeding the Mechanical Limit!)


Fermentables:
Pale Malt - 2450g - 32%
Wheat Malt - 1530g - 20%
Munich Malt - 1150g - 15%
Caramalt - 765g - 10%
Roasted Barley - 305g - 4%
Chocolate Malt - 305g - 4%
Flaked Barley - 305g - 4%
Flaked Maize - 230g - 3%
Flaked Oats - 150g - 2%
Black Malt - 150g - 2%
Brown Malt - 150g - 2%
Amber Malt - 150g - 2%

Hops:
Admiral @ 60 mins 70g
Whitbread Golding @ 10 mins 20g
Bobek @ 0 mins 10g

Final Volume: 15 Litres
Original Gravity: 1.110
Final Gravity: 1.034
Alcohol Content: 10.1% ABV
Total Liquor: 27.2 Litres
Mash Liquor: 19.2 Litres
Mash Efficiency: 75 %
Bitterness: 80 EBU
Colour: 464 EBC

T.watter Updates: http://twitter.com/pdtnc

The Pictures of this cock-up:
Mash Temp:

First Runnings:

FWH:

Boil-over after adding DSM:

OG:

At least 4 times as much Nottingham Yeast as I'd put in a normal brew:


I will brew something like this again, with a better recipe!!! Though I'll probably need some more Roasted Barley before I do.

This mornings Yeasty Action:

[leedsbrew]

Early start lad! Good to see! Looks like a kick ass brew! I'd love to get a brew on today but unfortunatly I've been at work since 8PM and am starting to loose my sanity!

Have fun

LB

[WishboneBrewery]

Cheers I was awake, it was light, birds were singing etc... Thought I may as well crack on

[coatesg]

There's a lot of adjunct in there and not a huge amount of pale malt to cope with it - you're gonna have to check and make sure it converts (and leave the mash a while longer to give it chance I guess).

[WishboneBrewery]

Hmmm... might be a bit late for that, I did a 90min Mash.... Pre-Boil Gravity is 1051 @ 40.5c which I think is 1040?! Wort tasted very sweet.
Just doing a second sparge for a Small (could be tiny) Beer, I'll see what the Gravity of this one is.

My thinking behind the malts was that the Compound effect of Pale+Wheat+Munich Malts = 67% which should be plenty to convert the unmalted cereal adjuncts which only total 9%

I can always bulk the boil out with some Spray malt, bit of sugar etc

[196osh]

Think you have the pre boil gravity back to front man.

Comes out at 1057 pre boil.

[196osh]

Also Munich as far as I am aware can convert itself but lacks sufficent enzymes to convert other starches. I think Wheat malt might be in the same boat but I am not sure.

Next time I would pump up the pale malt portion of the bill.

[WishboneBrewery]

At work they treat Wheat Malt, Munich, and Pale Malt as the same for Mashing purposes. You could be right about not having enough enzymes to convert other adjuncts.
Munich will have lower extraction, the all-munich beer I made had crappy efficiency.

Indeed I shall, I'll give it a bare minimum of 50-60% Pale malt probably more

[pantsmachine]

Like the mechanical limit photo. Exact same thing happened to me on my 1st IRS. You know what though? It was still a great beer and i learned a bit about paying attention to grain volume!

Hmmm... might be a bit late for that, I did a 90min Mash.... Pre-Boil Gravity is 1051 @ 40.5c which I think is 1040?! Wort tasted very sweet.
Just doing a second sparge for a Small (could be tiny) Beer, I'll see what the Gravity of this one is.

My thinking behind the malts was that the Compound effect of Pale+Wheat+Munich Malts = 67% which should be plenty to convert the unmalted cereal adjuncts which only total 9%

I can always bulk the boil out with some Spray malt, bit of sugar etc

I must be missing something here. How can your preboil be 1.051 when you were aiming for 1.110? IS it a 4 hour boil off of a massive volume of wort? Depressingly that's around about a 35% efficiency....so i know i've got it wrong somehow. Get a plastic plate drilled and fly sparge!

[WishboneBrewery]

I was missing something!!!
Needed more Pale Malt as a base. Probably not converted fully!

[pantsmachine]

No worries then, it will be full bodied and flavoursome just what you were aiming for.

[bellebouche]

I'm not following the maths here I'm afraid.. something's not right! All the malts should self convert and there'll be a load of diastatic goodness in that pale to do maize/oats etc.

I checked the specs on the munich I have and it's fine - equivalent to a pale in it's conversion capabilities.

A reliable arbiter of the success of the conversion is an iodine test. If you've not got a little vial of tincture then a quick visit to a pharmacy should see you right! That advice might be a little late in the day though here. I'd say fly-sparge the mashtun until it's running low level sugars (about 1008?) and then chuck the lot into the boil.

[simple one]

Maybe some sugar to thin it out toward the end of the fermentation?

[WishboneBrewery]

Its ended up at OG 1100 with DSM Tweaking!

[WishboneBrewery]

Troublesome Brewday now with picture evidence!
A bit annoyed it didn't go to plan but not that bothered... Still got something in the Fermenter that should hopefully be drinkable!!