Recipe: Lloydie P's Krispy Kolsch
Volume into fermenter: 20.79L (~5.5G)
Bag: Did not have one so went with the big square approach
Kettle: 48L aluminum, 40cm diameter
Fuel Source: 72,000 BTU propane burner
Because my schedule is so busy I did not have time to do many of the things I wanted to do before hand. This included - milling grain, measuring different water levels in my pot, trimming the voile square, testing the pulley, cleaning, sanitizing, etc. I figured much of this could be done during the mash and boils.. and part of that was true and part of it I should have known better
One thing I had done up front, and thank you to Stux and PP for helping me, was get my calculator working properly. That was a great help and learning experience. At the bottom of the calculator it told me based on my kettle how many cm of water I needed to add right from the start. Unfortunately for me I only had a ruler with inches on it and when I did the conversion to inches I choose the wrong value (I converted Liters to inches!). So when I stuck my ruler in my pot and was expecting to add something like 13.7" of water to a 14" high pot I knew something was amiss. Adding the grain would cause it to overflow. I wasn't sure how to proceed but I remembered a post on here a while back basically saying that calculators are great, but in the end you can always add more water or boil it off if you need to. So I just chose a spot on the pot that looked like it would give me enough head space with my grain and went with that. In hindsight (after I caught the error), the amount of water I added (36.9L) was actually very close to what I should have added (35.2L). Just 5% difference. So even though I was winging it I was not doing too bad.
I fired up the burner and as my 13.5C water increased towards my strike temp of 68C I milled the grains. I went past the strike temp to 71, but I figured that was ok because I would need time to get my bag set up. I just used bungee cords to secure it to the pot and did a little trimming with scissors. All good. At 68C I added the grain and then checked the temp. Down to 64C. A little flame and I was back at 66 (my mash temp). Covered the pot and wrapped some towels around it and for the next 20 minutes I ran around the house trying to organize things I would need later on. The process of checking temps and running around continued on for the rest of the mash. I was a little high most times.. 67 or 68 but given it was my first time I wasn't too concerned. After 90 mins I pulleyed the bag out of the pot and secured it in place. I was surprised how little it dripped. Thankfully I had purchased some industrial water proof gloves like The Commentary had told me to do. This allowed me to squeeze the bag in comfort and get out some more liquid. Then I tossed the bag in a pail and moved onto the boil. Wow that was easy. I thought AG was supposed to be difficult! My efficiency came out to 81%.
Flame on and it wasn't long before I hit 100C and then flame out to check measurements. I took a sample for a gravity reading and measured my volume (35.3L measured vs 33.7 theoretical). Then restarted the boil. Unfortunately at 30 minutes into the boil I literally kicked over my cooling gravity sample! I had not planned for this and decided to flame out and take a sample and then hope that maybe I could calculate my loss due to evaporation and somehow recover? I didn't know but pressed on anyway. The rest of the boil went well. A good rolling boil and no boilovers. At the end of the boil I had 30.54L vs the 25.32L I was supposed to have. I did not loose nearly as much to evaporation as I should have. I still don't know if that's normal or why there is such a large discrepency. I thought I read that evaporation rates are fairly predictable.
Too chill the beer I just hefted the very heavy pot into my laundry room and stuck it in the laundry tub with some circulating cold water on the outside. Half an hour later the pot wasn't warm and because it was getting quite late I decided to transfer the warm wort to the carboy and just do the aeration and pitching yeast steps the following day. 5.5 gallons went in the carboy and I covered it with saran wrap and called it a night. 12 hours later I took an OG reading, aerated, pitched the yeast and moved the carboy too my deep freeze on a timer. I'm hoping the timer will work as a make shift temp controller until the one I ordered from e-bay arrives.
Unfortunately My OG was lower than I would have liked. 1.040 vs 1.048. I think this is because I didn't loose as much water during evaporation as the calculator had projected so my concentration was lower?
All in all.. very happy with BIAB so far. Many many thanks too all who have put this amazing resource together!
Some questions:
1) How in the world are people checking their gravity when the wort is hot and making game time decisions on whether to add more water or boil off more water in order to hit their OG? Are they using a refractometer? It takes me at least half an hour for my wine theif sample to cool.. which obviously rules out any game time decisions.
2) Given that my efficiency was good, does the evaporation reasoning above make sense as to why my OG was low? What are the consequences of that lowered OG on the beer?
Thanks!
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