Sorry for the novel. I'm just giving every piece of info I can I think of so I can get some help.
Iím having 2 issues. I guess itíd be nice if one was the cause of the other, so I could fix everything with one fell swoop, but that may not be the case. Iím hoping some brains here can help.
The priority issue is my attenuation. I am ALWAYS stopping 4, 5, 6, even 7 points short of my target gravity. Iím using med-to-high attenuating liquid Wyeast yeasts, using a 1L starter on a stir plate for at least 24 hours, using a pinch of yeast nutrient for the starter, and adding a tsp of nutrient for the boil, using a siphon spray into my primary fermentor, and then shaking the ~5.2 gallons in the 6.5 gallon carboy (so thereís headroom for good splashing) for at least 2-3 minutes.
My grain bills are not particularly heavy on the unfermentables Ė they are almost always based off of some BYO recipe. Last one I did was a quasi-Guinness close: 7.5 lb Marris Otter, 0.5 lb flaked barley, 0.75 lb roasted barley, 2 oz chocolate. My OG was 1.043, right on target. I used Wyeastís 1764-Pacman from Rogue (expected to get 72-78% attenuation), fermented perfectly @ 63 degrees with the airlock bubbling solidly for 3-4 days and then slowing down for the 5th, and STILL sheís all tuckered out at 1.016, only 63% attenuation.
Just racked last night and itís a good beer, but noticeably sweet. I wanted a DRY stout, dang it!
Every beer I do is the same.
- Yeast count and health is fine.
- Recipe is fine.
- Fermentation is fine.
- Aside from getting an aeration stone, I really donít think thereís anything more I can do for O2 levels.
So, Iím thinking the problem has to be in my pre-boil processes, right?
Which leads me to issue #2; controlling my mash-out temps.
I heat my strike water and mash in a 10-gallon stainless steel kettle with a false bottom that sits above 1.5 gallons of water. I always aim for strike water 11 degrees above my mash target (which, for the Dry stout, was 150), and after pouring in the grain and stirring a few minutes to break up clumps, my built-in dial thermometer and my handheld probe thermometer both tell me Iím within a degree of target. Happiness abounds.
Regarding that 1.5 gallons of water under my false bottom. Thatís a pretty heavy chuck of heat down there, which I canít get to with my spoon when I stir in the grains. Is it possible that my temp readings are only telling me whatís happening at the top and middle of my mash, but nearer that false bottom where the water once was 161 degrees, the mash is really closer to 155 or higher? Does anybody else have a mash-tun like mine (bought from MoreBeer)? Should I be recirculating a few quarts and stirring before I wrap up the mash to let sit?
After mashing 60 min, I (attempt to) MASH OUT.
I apply direct heat, and begin recirculating+stirring. I draw off a quart at a time, put it back in pouring it gently over the back of my metal spoon so as not to aerate, and stir the mash to try to disperse the heat. I do this about 5-6 times, watching my built-in dial thermometer. 15 min later or so, the thermometer tells me Iím just about @ 170. I shut off the heat, recirculate once or twice more and start my sparge. 5 minutes into the sparge, my dial thermometer starts wigging out, rapidly climbing higher and higher, soon telling me Iím up to 195! I get angry and call it a liar. About 10 minutes after that, itís back down to 148, and slowly but steadily dropping down through the 140ís (despite the fact that Iím using sparge water @ about 180 degrees).
So, Iíve just about had it with this mash-out process which seems like it is probably doing more bad than good. Next time Iím going to try to mash out by adding a quantity of boiling water.
In calculating how much water I need, BeerSmith asks me how much grain Iíve got and how much water Iíve got. Of course itís referring to the water Iím using to mash (1.3 q/lb), but should I also consider the 1.5 gallons of water below the false bottom in this calculation? It seems I should since it must have an effect on the total heat present. Iím wondering how much that 1.5 gallons is to blame for many of my issues.
Is there a possibility that these wacky temps Iím getting during Ďmash outí are having an effect on conversion or are otherwise the cause of my miserable attenuation?