I cooked up my first Double IPA recipe over the weekend but have seriously missed the mark with the target gravity. So much so it most definitely won't be a Double.
Target O.G. = 1.085
Actual O.G. = 1.050
The malt bill was as follows:
75% Maris Otter 12.5% Malted flaked oats 10% CaraHell 2.5% CaraPils
A volume of 30L gave me a rough required extract for 1.085 gravity of 6.66kg. After adjusting the weights for their efficiencies/max yield I came out with:
Weight Max Yield Actual weight Maris Otter 75% 4.995kg 82.5% 6.055kg Malted flaked oats 12.5% 0.833kg 70.0% 1.190kg CaraHell 10% 0.666kg 74.0% 0.900kg CaraPils 2.5% 0.167kg 71.4% 0.234kg
This gave me a total weight of 8.401kg. My mash and sparge volumes were:
Mash = 26L
Sparge = 16L
The mash started off a little too hot and so I ended up doing a 150 minute mash. The readings went as so:
T = 0 temp = 72.7ºC T = 20 temp = 71.6ºC T = 40 temp = 70.1ºC T = 60 temp = 68.0ºC T = 80 temp = 66.5ºC T = 100 temp = 65.8ºC T = 120 temp = 65.4ºC T = 150 temp = 64.9ºC
After transferring the wort to the boiler, where it sat on at a low setting for a couple of minutes while I added the sparge water to the mash tun, I had a wort temperature of 68.4ºC and a gravity reading of 1.034. Adjusted for temperature using brewers friend it came out with a reading of 1.051. I was a bit despondent at seeing this.
My sparge after finishing had a reading of 1.017 and a temperature of 73.1ºC. Brewers friend only goes to 71ºC but it gives a rough gravity of 1.035.
There were 400g of hops in the boil/flame out. After boiling and cooling the wort I topped it up with about 3.5L of the leftover sparge water and a further 2.5L of water to top it up to 30L (I also used some of that sparge water to top up the boil). My end gravity was 1.050.
Writing this out I realise I did not adjust my recipe for brewhouse efficiency. However, assuming I did nothing wrong, that gives me an appalling efficiency of 58.8%. That is so bad I think there was something more to it. Had the gravity been in the region of 1.064 I could safely write this off as a failure to accommodate for the brewhouse efficiency.
So while I aimed for 1.085, after adjusting for a rough brewhouse efficiency of 75% I should have hit 1.064. I actually hit 1.050.
- Why was I so far off the mark?
- Are there any tips for consistently hitting high target gravities?