Nice one MyQul, but just to check, I have a 21L pot, if I'm going to do two dunk sparges (I've leaned towards dunk sparge since I first heard about it, it just seems more efficient and the idea of doing it twice is right up my street) how much water am I starting with? And how much on each dunk sparge. Would it be something like 10L of water to mash with and 2 x 5L sparge? My initial thoughts were 14L mash, a 6L dunk sparge and then chuck 100g of honey into 3L, boil it and add to the FV when cool to bring it up to 23L and somewhere about 1060 which is my preferred SG.
By the way, your advice on re-pitching the yeast worked a treat and I'm now a born again fundamentalist re-pitcher. Every second brew is getting re-pitched from now on, you cut my yeast bill in half in one fell swoop.
Thats the thing I like about maxi biab everything is controlled by the size of the kit you have, so no messing about doing lots of water calculations - the only one you have to do is at the end to see how much you need to dilute the concentrated wort by. I use this calculator:
http://www.brewersfriend.com/dilution-and-boiloff-gravity-calculator/
It's the first one and pretty spot on.
As far as water volumes go:
Mash volume:- I fill my pot right up to the top then heat to strike temp. I then take approx 5L out. The reason it 5L is because that what my smaller pot holds that I use for heating up the sparge water.
Dunk sparge 1: My 5L pot plus one kettle full. My kettle is 1.7L to the fill line so 6.7L
Dunk Sparge 2: 2 Kettle fulls so 2x1.7L = 3.4L
I am going try just doing 1 dunk sparge next brew with all the water in one bucket (well my second FV) to see if there's any difference. Will save some time if there isn't
Some tips that I have found work for me:
- When you dough in it's pretty thick which may lead to dough balls. Use a balloon whisk to give the mash a good stir and this quickly and easily breaks them up if there are any
- Because of the concentrated nature of the mash you need to do all you can to get a decent efficiency: 1) Stir the mash about half way through. You can do it more if you want about ever 20-30 mins 2) Either squeeze the bag like it owes you money (I don't like doing this as it is so messy) or do an extended lauter. Put a colender in the bottom of a bucket or whatever. After you yank the grain bag put it in the bucket and leave it there for about half an hour. You'll be surprised at how much runnings come out. Bring these to the boil seperately from the main boil, then add to the main boil.If you dont chucking em in the main boil brings it off the boil throwing out you hop addition times because you need to bring the wort back up to the boil - which of course takes additional time
If you get to the end of your boil and you still haven't added all the extra runnings to the main boil, don't worry. As long as they've been boiled for 15 minutes you can just add them into the fermenter. However this has never happened to me. The boil off usually makes
just enough room (and were talking boiling to the brim here - so the roll of the boil is about 1cm or 2cm from the top of the pot) to add all the addtional runnings in the boil time. Failing that you could do a 90 min boil
- Doing a concentrated boil leads to a lower hop utilisation. I always add 5 IBU extra to the bittering addition to compensate. I've tried using calculators for this but couldn't make them work for me - beer always came out too bitter. So I came to the 5 IBU is from trial and error. This might be my personal taste and maybe you might need to add more. Having said all that, I am aware there are plentty of other maxi-BIABers that don't bother adding any extra hops
Re yeast. You can re-pitch more than one generation. So you don't have to use another packet ever other brew. Wyeast/Whitelabs sites say a max of 10 generations but there's anecdotal evidence from the other forums to say you can go far beyond that. If you ever get into top cropping, you can do that infinately