Thursday, November 10, 2011

Designing and brewing a beer

This post describes the process I went through designing and brewing my first batch from scratch.

If you've never thought about crafting your own beer, think again. I had made all-grain beers from kits for about a year when I decided to make one from scratch. The fact that Santa got me a BarleyCrusher, accurate scale and the book Designing Great Beers (Ray Daniels), I knew it was time. The gift certificate to my LHBS helped as well.

I decided to design a british bitter ale because I enjoy lighter body beers.

Grain Bill Calculation
Step 1: Determine malt ratios, based loosely on style
85% Pale ale malt
8% Crystal malt
5% Wheat
2% Cara-pils dextrin

Step 2: Determine target gravity units for 5 gals
target = 1.035 = 35 GU's
35 GU's * 5.5 gals = 193

Step 3: How many GU's will each grain source contribute?
Pale = 0.85 * 193 = 164
Crystal = 0.08 * 193 = 15.44
Wheat = 0.05 * 193 = 9.65
Cara-pils = 0.02 * 193 = 3.86

Step 4: Determine weights of each grain
Assumes a 68% efficiency.
Max potential per grain is the second number in the formulas.
Pale = 164/36*0.68 = 164/24.48 = 6.7 lbs
Crystal = 15.44/34*0.68 = 15.44/23.12 = 0.67 lbs
Wheat = 9.65/38*0.68 = 9.65/25.84 = 0.37 lbs
Cara-pils = 3.86/36*0.68 = 3.86/24.48 = 0.15 lbs

Other ingredients and process
Boil hops: 1 oz 5.5A UK Kent Goldings pellets
Flavor hops: 0.5 oz 5.1A Fuggle
No aroma hops, I didn't want to assault the nose.
Yeast: Wyeast 1098 british ale, 30 oz starter.
Water salts:Used 1 oz CaCl + MgS04 in chlorinated water that had sat out overnight.
Mash: 90 minutes @ 153df.
Sparge: Fly sparge with 175df water, with a stir/recirc halfway through.

Efficiency Calculation
The efficiency tells you how good your system is at extracting sugars from the grain. An efficiency of 100% is perfect, but impossible. Most brewers shoot for around 70%. My calculations were based upon 68% as mentioned above. I wanted to see how well my system performed for future calculations.

Boil gravity (after last sparge) = 1.032 = 32 GU's (make sure you chill before hydro)

Boil volume = 7.5 gal

E = GU's * Vol / max potential

Max potential = (6.7 * 36) + (0.67 * 34) + (0.37 * 38) + (0.15 * 36) = 283.44

E = 7.5 * 32 / 283.44 = 84.67%

Important note (lessons learned)!
My OG was 1.040 instead of 1.035. This was due to the fact that my grain bill was based upon a 68% efficiency, and my system performed better. Had I known I would have reached 85% efficiency, this would have resulted in a smaller grain bill, and my OG would be much closer to target. So the resulting beer was pushing the style a little and approaches a special bitter due to alcohol and body.

Think of it as miles per gallon in a car. If you're shooting for 300 miles, and your car gets 30 MPG and has a 17 gallon tank, you should fill the tank with 10 gallons. When it runs out, you should be around 300 miles. But your car actually got 32 MPG, so you overshot the finish line by 20 miles. You could have gotten away with less fuel.

I made a beer nobody else has ever made. The only way someone could make this same beer would be to use the grain and ratios I used, along with the same hops, yeast, water, and techniques. The end product was absolutely delicious, and I will make it again.

If you made the move from extract or partial mash to all grain, it definitely doesn't end there. I highly suggest reading Designing Great Beers by Ray Daniels.

No comments: