Imperial Stout - Help!

Beer Recipes
1

We are planning on brewing an all grain imperial stout. I have attached the recipe and would really appreciate some feedback. Not sure about the quantities of malt used but from the research I have undertaken is seems to be quite reasonable.

Furthermore, I have used the Bru’n software to develop the water profile for this beer. I have chosen the option of Black Balanced to achieve the following parameters

Ca: 60
Mg: 10
Na: 20
SO4: 47
Cl: 38
HCO3: 160

My starting water profile is:

Ca: 48
Mg: 14
Na: 12
SO4: 36
Cl: 37
HCO3: 158

To this water we added 0.04 grams/L gypsum, 0.02 grams/L of NaCl. The total amount of water used is 70 litres - 50 litres to mash and 20 litres to sparge:

Ca: 57
Mg: 14
Na: 20
SO4: 58
Cl: 39
HCO3: 158

It is quite close to the one specified by the water software.

Adding the malts we get a mash pH of 3.4 which is extremely low. We are not sure where we have gone wrong. Could it be because of the malts used? As you can see the water profile is low on alkalinity however increasing it would imply deviating from what the Bru’n software recomends.

Any and all help would be seriously appreciated. Thanks!

Type: All Grain
Batch Size: 40,00 l
Boil Size: 50,64 l
Boil Time: 90 min
End of Boil Vol: 42,64 l
Final Bottling Vol: 40,00 l
Fermentation: Ale, Single Stage
Date: 18 Jan 2016

Efficiency: 72,00 %
Est Mash Efficiency: 73,8 %

Ingredients
Amt Name Type # %/IBU
80,00 l Agua Pinillo Water 1 -
15,40 kg Pale Malt, Maris Otter (5,9 EBC) Grain 2 86,7 %
0,50 kg Caramel/Crystal Malt -120L (150,0 EBC) Grain 3 2,8 %
0,50 kg Chocolate Malt (886,5 EBC) Grain 4 2,8 %
0,44 kg Biscuit Malt (45,3 EBC) Grain 5 2,5 %
0,44 kg Cara-Pils/Dextrine (3,9 EBC) Grain 6 2,5 %
0,29 kg Roasted Barley (1250,0 EBC) Grain 7 1,7 %
0,20 kg Black Barley (Stout) (985,0 EBC) Grain 8 1,1 %
92,60 g Target [11,00 %] - Boil 60,0 min Hop 9 47,8 IBUs
46,30 g Admiral [14,75 %] - Boil 30,0 min Hop 10 22,8 IBUs
4,0 pkg British Ale Yeast (Mangrove Jack’s #M07) Yeast 11 -
Est Original Gravity: 1,099 SG
Est Final Gravity: 1,025 SG
Estimated Alcohol by Vol: 9,8 %
Bitterness: 70,6 IBUs
Est Color: 79,9 EBC
Measured Original Gravity: 1,046 SG
Measured Final Gravity: 1,010 SG
Actual Alcohol by Vol: 4,7 %
Calories: 427,1 kcal/l

Mash Name: Infusión simple + Mashout
Sparge Water: 6,13 l
Sparge Temperature: 98,0 C
Adjust Temp for Equipment: TRUE
Total Grain Weight: 17,78 kg
Grain Temperature: 20,0 C
Tun Temperature: 20,0 C
Mash PH: 5,20
Mash Steps
Name Description Step Temperature Step Time
Infusion simple Add 37,03 l of water at 75,7 C 66,0 C 80 min
Moshout Add 29,63 l of water at 96,2 C 78,0 C 10 min

2

You are going to need a lot more roasted barley. Should be around 10% of your grist. There’s no need for the cara pils. You should remove it.

3

I would also cut the carapils and black malt. Up your chocolate and roasted barley.

That pH isn’t going to work for you. I add baking soda to my water to raise the mash pH to about 5.6 for my dark beers. I certainly would recommend mashing higher than 5.2. As far as the low pH in your Bru’n water… Did you adjust the water amounts? I’ve forgotten to do that.

4

+1.  More roasted barley and chocolate + 5.6 mash pH for sure.

5

The mash PH in Bru’n Water says 3.4 estimate?  Putting in the information you provided the only way I got close to that is if I called the 15.4kg Marris Otter a ‘Roast Malt’ instead of ‘Base Malt.’  If I select it as a ‘Base Malt’ it estimates PH 5.6, if select ‘Roast Malt’ it goes to PH 3.5.

6

Yes! Thats just what I did. Silly mistake regarding the water. :cry:

About the malts, I’ll take off carapils and add more roasted barley and maybe more chocolate, al though I have a feeling it’ll come out very sweet and I would prefer it a bit dry. Maybe add up a bit of black malt or will it be too high? Does 70ibu make sense?
First time trying a stout… :-\

Thanks in advance!!

7

Glad we got the water figured out. If you’re worried about it being too sweet, I’d drop the biscuit malt too. But definetely kick the roast malts up a notch. Mash low at about 148 degrees for 90 minutes. 70 IBUs is fine.

8

try to hit 5.4 pH for a little more dry stout, like an Irish Stout.  If you are looking for that full rich, smooth roasted character having harder water and higher pH in the 5.6 range will get you there.  I like a touch of midnight wheat in my Imp Stout for head retention and some body.  But I would not use American Roasted Barley, try to find UK.

IBU I like the low 60’s
But I would use the Bitter Hops Admiral for the long boil and the Aroma hops like fuggle or target for your late hop addition.

9

I agree on ditching the carapils and adding considerably more roasted barley and chocolate malt. I like a little black malt in my stouts but if you’re adding a lot more chocolate malt then I’d probably ditch the black malt. Biscuit malt is interesting in stouts. It works but it definitely stands out as a biscuit flavor even in low amounts. Probably not something to add unless you really want that flavor.

10

There’s no way the Midnight wheat contributes to any head retention, though I do agree it has a nice flavor.

11

It throws some protein in the mix doesn’t it?  I am not sure the roast completely denatures the wheat.

12

Replace the Biscuit Malt with Special B. You will be glad you did. I agree with the others on no Dextrine and upping the roasted barley.

13

Not enough to matter at the low percentage you would be using it.

14

good point.