Critique my first custom recipe (IIPA)

Slow Burn Imperial IPA
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13.2 lbs. Plain Light Malt Extract
2 lb. Crushed Crystal Malt 60L quart capacity
1 lb. Crushed Victory
6 oz. Cascade Hops
1 oz. simcoe Hops
5 oz. Priming Sugar
1 11 gram package Nottingham Dry Yeast

estimated steeping efficency: 40%

expected OG: 1.106
expected FG: 1.015
expected ABV: 11.7%
expected IBU: 48
color: 38 HCU (~18 SRM)


PROCEDURES
1. Pour 3.5 gallons of clean water into brew kettle. Steep crushed grains @ 150° for 30 minutes.

2. Carefully remove the grain bag and sparge with 1.25 gallons of 170° water. allow all water to drain into the brewpot without squeezing.

3. Heat the brewpot water to boiling. Add 6.6 lbs of malt extract. Stir constantly until it returns to a boil.

4. Once pot is boiling follow the hopping Schedule Below
2 oz cascade at 60 min
1 oz cascade at 35 min
1 oz cascade at 25 min
1 oz cascade at 15 min
1 oz cascade at 5 min

5. with 20 minutes remaining in boil add the remainin 6.6 lbs of malt extract

6. cool wort to 70°. transfer to primary and add yeast.

7. primary for no less than 2 weeks

8. secondary for no less than 2 weeks

9. Dry Hop with 1 oz. simcoe Hops for 7-14 days

I have no personal experience with a beer that big but I think at 48 IBU you are light. I would pump it up into the 60's as it would give a better balance.

48 IBUs is very light, especially for something that's 11+% ABV

Wayyy too light on the hops, if the OG was closer to the 60 mark, it would be much more balanced.

Yup for an IPA you'd want a 1:1 BU/GU ratio. Also, why not use some high AA% hops at the 60 min mark and save your cascades until later?

thanks. you guys have hit on my biggest fear with this beer. I was concerned with the relatively low IBU. I wanted to use centennial for the bittering hops at 60 minutes but my LHBS was out when I was in last time. Maybe I can go with 2oz Nugget or Chinook if they are still out of centennial. That would get me up to over 80 IBU.

thanks for your help.