Originally Posted by MeanDeuce
Couple of questions regarding the extract version:
1) I plugged the extract recipe into Beersmith and my ABV is only 5.1%. Any ideas why its so low?
2) If I wanted to do BIAB, I'd steep the grains along with the FWH addition for 30 mins at 150ish?
Disclaimer: haven't brewed this yet, but planning to do the extract version next week so I'm pulling my recipe together and doing lots of reading on partial mash techniques (this will be my first partial mash).
1) Reading this and the other Zombie Dust recipe thread, it looks like people following the front page recipe have often come up short on original gravity (and hence ABV). I wonder if they're assuming the extract target volume is also 6 gallons? (If you read carefully, he says the extract assumes you'll be shooting for 5 gallons, not 6 gallons like the all-grain version). If you apply a standard conversion ratio (1lb grain = .75 lb LME = .6 lb DME) to the all-grain recipe, and account for the fact that the all-grain is for 6 gallons and the extract is for 5 gallons, the 6 lbs DME is about right. Having said that, when I plug this into Beersmith it also tells me that I need more extract to hit the target OG of 1.065. I'm going to follow Beersmith to make my 5.5 gallon batch and use a bit more extract than called for here (8.5 lb LME, which would equate to 7.7 lb LME or 6.2 lb DME in a 5 gallon batch). Will post back if I overshoot the OG.
2) Re: doing the partial mash, there's a great thread discussing various approaches here: http://www.homebrewtalk.com/f39/easy-partial-mash-brewing-pics-75231/
Basically though, you need to "mash" the Munich, Carafoam, Crystal and Melanoiden at ~ 152 F for 30 mins - 1 hour with a limited amount of water (people often recommend 1.25 qts / lb of grain). So here that would be 3.125 qts (1.25 qts/lb * 2.5 lbs grain). You don't just want to toss the grain into 152F water though, b/c the grain will cool it down a good bit. So use this calculator: http://www.rackers.org/calcs.shtml
to figure out what temp you should heat your water to before dropping in the grain (for me, assuming the grain will be at 68F room temp, it tells me to heat the water to 168F).
For the FWH, those go in AFTER the grains are removed from the mash (at which point you have created "first wort" for these hops to go into). I do a full boil for my extract brews so I plan to "sparge" (rinse) my grains in my brew pot for 10-15 mins at 170F with the remaining volume of water needed to get my boil volume (~5.7 gallons), while the FWH marinate in the first wort. Then I'll remove the grains from the brew pot, dump the now-hopped first wort into my brew pot, and carry on with my brew day.
Like I say, I haven't tried this yet, but after reading up on partial mashing and FWH I think this is a reasonable approach. Good luck with your brew (and hopefully you'll wish me the same)!