Chubby cherub IBU & ABV question

[Mikes15]

Looking at doing a chubby cherub ; 

Coopers Recipe

Since Im learning my way with using a recipe calc & thought I might even up the hops a bit I put it into the Brewers Friend calc ;

My-chubby-cherub

But,,, I'm not getting anything like the figures stated on the recipe for the same ingredients & hop schedule?

Coopers =
Alcohol Content = 5.4%
Colour (EBC) = 27
Bitterness (IBU) = 38

My Calc =
Alcohol Content = 4.32%
Colour (EBC Morey) = 12.6
Bitterness (IBU) = 52.48

Any thoughts?

 

[Otto Von Blotto]

From the look of the beer on the Coopers recipe page the 27 ebc sounds high, but 12.6 sounds low as well, I'd guess it would be somewhere in the middle of those two figures with the amber extract. Not sure why the other figures are so different, maybe it underestimated the OG. 

[PB2]

1.5kg Amber Malt Extract 340EBC
1.5kg Light Malt Extract 55EBC
0.5kg Light Dry Malt 55EBC (equal to 0.625kg liquid malt extract at 80% solids)

[(340 x 1.5) + (55 x 1.5) + (55 x 0.625)] / 23 = 27EBC 

[Mikes15]

Im actually not that bothered by the EBC as that's just colour right?,  prob just the diff between Au & US malt specs.

It was the amount of suggested extra bitterness that threw me as they are almost at opposite ends of the range for a APA.

Happy to brew the original recipe but might throw 15-20g of cascade into the DH schedule just because!

OG is;-
1.5kg Amber Malt Extract 19.05
1.5kg Light Malt Extract 19.05
0.5kg Light Dry Malt 7.62
Total OG = 1046
FG = 1013

Aside from the option of extra hopping I really put it in the Cal for practice.

[Norris!]

The boil volume might be set to 23l instead of whatever volume coopers suggested so that would increase the efficiency of the hops used, upping the bitterness.

[Mikes15]

10 minutes ago, Norris! said:

The boil volume might be set to 23l instead of whatever volume coopers suggested so that would increase the efficiency of the hops used, upping the bitterness.

Ta but Na,

5ltr 25min boil, 23ltr batch, check all the details over x3.

25g Chinook 25min boil = 28.51 IBU
25g Nelson sauvion 15min boil = 19.57 IBU
25g Cascade 5min boil = 4.40 IBU

25g Chinook DH = O IBU.

[Beerlust]

Hi Mike.

The reason your IBU number is different is likely due to the alpha acid level of the hops you have entered in your recipe compared with the alpha acid levels Coopers used when they constructed the recipe. Check the levels on each of these hops you have in your fridge against the numbers used in the Brewers Friend calculator & adjust where necessary. Currently the alpha levels of these hops in my fridge are as follows... Chinook = 11.6%AA (=22.07 IBU's in the recipe), Nelson Sauvin = 11.5%AA (=15.63 IBU's in the recipe), Cascade = 8.4%AA (=4.57 IBU's in the recipe). Total IBU = 42.2 IBU.

If your alpha levels actually match those listed in your Brewers Friend recipe then drop the Chinook amount a little to get your total IBU count to somewhere near 45ish. 

There are two reasons the ABV% of your recipe is low. The first being that the Brewers Friend calculator does not take into account secondary priming sugars (used when bottling) that add approx. 0.4-0.5% ABV on top of the primary wort fermentation ABV. It only gives figures for fermenting out the primary wort.

The second is the apparent yeast attenuation. Your recipe states 72%, whereas Coopers DIY recipe suggests attenuation somewhere up around 77-80% using the Lallemand BRY-97, that will create more ABV as well.

I've made this DIY recipe back when I was still bottling my beer & it was terrific! If I was to make it today for the keg, I'd add roughly the same amount of priming sugar/dextrose used to carbonate the beer into the primary fermentation instead, to keep the ABV & balance the same as the bottled version.

I hope that helps.

Lusty.

[Mikes15]

Thanks V. Much fella,

So,

LHBS Chinook = 12 - 14%,
Cal = 13%
LHBS Nelson Sauvin = 10 - 13%
Cal = 12.5%
LHBS list Cascade = 4.5 - 8.9%,
Cal = 7%

Seems to line up so Coopers must have some lower Acid hops in there cupboards!

Dropped the Hop boil additions for the Chinook & Nelson from 25 to 20g IBUs down from 52.48 to 42.87 .

Adding 140g of cane sugar as a late addition to allow for priming ABV is up to 4.63% from 4.32%, I can modify the attenuation but I've been getting to 1010 - 1008 every brew so that will prob be 5% easy.

Think I will go with 25g cascade DH along with the 25g Chinook Coopers use, they sound like they will go well together, don't think Ill DH any Nelson, might be a bit to much.

[Otto Von Blotto]

Do they not have the actual alpha acid content on the hop packages? Makes it pretty difficult just having a range, you don't really know how much bitterness you're adding.

[Mikes15]

2 hours ago, Otto Von Blotto said:

Do they not have the actual alpha acid content on the hop packages? Makes it pretty difficult just having a range, you don't really know how much bitterness you're adding.

Yes they will but I haven't purchased them yet as the amount required was subject to this thread! 

[Otto Von Blotto]

Perhaps just get the hops first then adjust quantities to suit. You can always use any leftovers in another batch or dry hop them

[Mikes15]

1 hour ago, Otto Von Blotto said:

Perhaps just get the hops first then adjust quantities to suit. You can always use any leftovers in another batch or dry hop them

Yeah I do just that, order 25g each for the boil, adjust when they arrive & just chuck the 5-8g left overs in as a DH, other option I guess would be to adjust the boil times slightly but extra DH wont be a bad thing.