I got this recipe from my LHBS (Local Home Brew Shop) as a recipe of the month at 1/2 price! It came as a pumpkin porter, but since I already have a Scottish pumpkin ale in the works, I decided to “de-pumpkin-ni-fie” the recipe, add a little maltodextrin and just make a Robust Porter. The name McQuinn comes from my paternal grandmother’s maiden name…and it sounds good for a porter!
I’m trying to input my recipes and brewing sessions into Brewer’s Friend online, but they include some technical stuff that I’m not into yet. They also do not account for things like sugars or fermentables that aren’t part of the “mash” or grain steep. (I’m doing BIAB–brew in a bag–all grain brewing).
So, when going from end of mash specific gravity reading, to pre-boil, to end of boil, the calculations show my conversion of grain to sugar and mash efficiency to be over 100% I’m also getting confused on water volume, grain absorbtion, boil off rate, etc. I start with 6 gallons in the kettle to mash, I know the grain absorbs some and the calculations have a standard default. Then I do what I’m calling a modified “sparge” where I drain heated water over the grains to hopefully wash out some more sugars from the grains…so, I’m adding about 2 gallons back.
Starting at 6 gallons and adding 2 gallons, minus what the grains absorbed, should leave me with about 7 gallons, but I swear I had 8 for the start of my boil. Had to keep the boil slow for most of the hour, because of the volume. Then I wound up with a slam full fermentation bucket.
I had to actually pull out a gallon to process separately, after I pitched the yeast. I used an oxygen tank with an aeration stone to aerate the wort for two minutes. I’m using Mangrove Jack’s British Ale Yeast. I was supposed to have 5.5 gallons after the boil.
The other thing that throws me off on all-grain brewing is the amount of trub. If you want a nice clear beer, you rack maybe 5.25 gallons off of 6 gallons and the rack again to 4-1/2 for bottling. I don’t care too much about getting a higher alcohol by volume (ABV) so much as I was a good beer and I want my 5 gallons! Ah well. C’est la biere!
So, I keep trying to tweak the brewing program and make notes that explain discrepancies, but it can be confusing. The main thing is that the actual brewing went well…except the temperature dropped in the mash at one point and I fired the burner to boost it and I over-shot from the 153 target, up to 157F. I stirred constantly for over 15 minutes to get it back down. Temperature control in the mash is the bane of my beer making! I’m not sure how it would do in an accurately judged competition, but my stuff still seems to come out pretty well, so I guess it’s okay. At the end of the brew, the color looks good and the OG reading is spot-on at 1.063 with an anticipated ABV of 6.32%.
Despite the brewing program confusion and water volume weirdness, this should be a pretty decent porter…and I have an extra gallon or so to experiment with. I’m using blow off tubes, since this is a dark beer and the volume is high.
I may wind up combining them at secondary and then dividing them again at bottling time and add cold brewed coffee to one half or one quarter.
If anyone would like the details of the recipe, I am happy to share…let’s see how it turns out, though!
Update: 10/6/14 The porter has been chugging away all day!
Update: 10/8/14 It has only been a couple of days since brewing and the porter has already gone through a quick chugging fermentation period and by yesterday afternoon, had already slowed substantially. I think I might go ahead and switch from blow off tubes to regular airlocks. I don’t know if this is normal for Mangrove Jack’s British Ale Yeast…I have to assume so.