Making the jump from mini-mash to small batch BIAB all-grain; advice please

[FatsSchindee]

Been been doing mini-mashes on my last few (5 gal) brews, and realized that although I don't have the equipment or capacity to make the jump to all-grain, full volume boils for 5 gal batches, if I go BIAB and half-sized (2.5-3 gal) batches, I can easily make the transition to all-grain and full volume boils without any new equipment! (And with only one case of beer that I "have to" drink, I'll be able to brew more often without SWMBO complaining about all my beer piling up around the house.) So I've been reading up on the method and any changes I'll have to make, and just wanted to run my proposed process by you guys and get your feedback and suggestions about what you think will and won't work, please...

I have 5 and a 3.5 gal SS kettles. For the mini-mashes I've been doing, I've been using a 5 gal paint strainer bags from Home Depot, and using Deathbrewer's method from the sticky on here - mashing in one pot for an hour (using a towel wrapped around for insulation), and then dunk sparging in the other pot with 170* water for ten minutes, and then combining the worts for the boil (to which I've added water to bring up to partial boil volumes of 3.5-4 gal). On my last couple mini-mashes this way, I've measured the pre-boil OG (before topping up), and calculated efficiencies of right around 78%. This was using 1.4-1.5 qt/lb grain for the mash, and similar volumes for the sparge (anywhere from .5 to 1.5 times the mash volume). This was only using around 2-3 lbs of grain for the mini-mash, though.

My first questions relate to this: can I use this same mash thickness scaled up for bigger all-grain BIAB? Or, if I go with a thinner mash (what I've been reading many of you BIABers do, around 3 qt/lb? Or just full volume mash, with no sparge, whatever ratio that comes out to be), can I still expect the same efficiency? I'm thinking not if I don't sparge, based on what I've been reading. How much of a hit do you take on efficiency from not sparging? For a concrete example, I'm working on an APA recipe (originally conceived as a mini-mash), and I've converted it to a 6lb grist all-grain recipe, as follows:

4.75 lbs Pale Ale 2-row (79.17%)
8oz Munich Malt light (8.33%)
6oz Crystal40 Malt (6.25%)
6oz Victory Malt (6.25%)

Working backward to come up with volumes...
I want 2.5 gal finished beer, so I want 2.75 into fermentor (I assume about 0.25 gal trub loss). I boil off 0.5 gal/hr in my 5 gal kettle, so I want 3.25 gal pre-boil for a 60 min boil. Using 0.13 gal/lb grain adsorption, that's an additional 0.78 gal pre-mash, or 4.03 gals total. To make the math easier, let's just call it 4 gal... So now I want to figure the best way (mash thickness) to split this up this 4 gal between the mash and the sparge water. If I use 1.5 qt/lb, that gives me 9 qt (or 2.25 gal) for the mash, and then 7 qt (1.75 gal for the sparge). If I use an equal amount for mash and sparge (2 gal ea.), that's not too different of a ratio, 1.66 qt/lb. If I do a full volume mash with no sparge, that would be a thinner 2.66 qt/lb... Closer to the 3 qt/lb John Palmer quoted in the BrewStrong podcast about BIAB I just listened to.

So my question boils down to this, basically: is there an advantage to a thinner mash over a thicker mash, that will offset the disadvantage of lost efficiency from not sparging? The above grist, using the 78% I've previously hit, gives me an OG of 1.057 and a projected ABV of 5.67%. Without the sparge, what kind of efficiencies are y'all getting? 65% maybe? With that, I'd get 1.048 and 4.8%... Still within style guidelines. Much less than that, though, would put it below style... and also I'd want to know what to expect beforehand, so I could adjust hops accordingly to not over-bitter and throw my BU/GU balance off. One quoted advantage to no sparge is one less pot to wash, but since I've been using the two pot method for my mini-mashes, I'm used to it anyway and it really is only another couples minutes to wash it, so that advantage doesn't matter to me. I'm thinking more water chemistry... I haven't read enough about it yet, but is there something to do with pH changing with different mash volumes/ratios?

Which leads me to my next question: now that I'm not using any extract, should I start messing with water chemistry for the all-grain BIABs? I always used RO water for my previous brews, assuming the extract has the needed chemicals/molecules/whatever, and haven't had any taste issues because of that. Since this is my first APA, I had planned on using some gypsum anyway (1/2 tsp for 2.5 gal), even with the extract I was going to initially use. If all-grain, though, will just some gypsum be enough to add to RO water, or will I need to do more? (This is one area I obviously need to do much more learning in - don't know much at all yet.)

Anything else about a first-time BIAB all-grain I'm missing (I'll be doing a starter with WLP001, have temp control for fermentation, etc. - mainly just the mashing steps I'm focusing on)? Any and all advice is appreciated - thanks!

 

[FatsSchindee]

Sorry, also forgot to add (and the edit function screws up all the formatting/paragraphs, so just easier to reply to my own post)... Thinking about the full volume mash, I don't know if my 5 gal kettle will even hold 4 gal of water and 6 lbs of grain... I assume that much grain would displace at least one gal of water, would it not? Maybe another reason for me to split the water into two pots for mash and sparging.

I do also understand an advantage of a full vol mash would be better temp maintenance (more thermal mass), but also forgot to mention that on the first post.

 

[Yooper]

Sorry, also forgot to add (and the edit function screws up all the formatting/paragraphs, so just easier to reply to my own post)... Thinking about the full volume mash, I don't know if my 5 gal kettle will even hold 4 gal of water and 6 lbs of grain... I assume that much grain would displace at least one gal of water, would it not? Maybe another reason for me to split the water into two pots for mash and sparging.

I do also understand an advantage of a full vol mash would be better temp maintenance (more thermal mass), but also forgot to mention that on the first post.

On the rackers.org website (here: http://www.rackers.org/calcs.shtml) there is a "can I mash it?" tool that calculates how much space the volume of the water plus the mash would take up. I use it when I question if something will fit!

I don't BIAB, so I can't give specific advice on technique, but you can certainly do a mash and separate sparge.

 

[WoodlandBrew]

Here is some more information that may help you with mash and sparge volumes:
http://woodlandbrew.blogspot.com/2012/12/when-more-grain-doesnt-add-more-sugar.html

My book has more tables and further discussion.

 

[C-Rider]

I often mash 6+ lbs of grain in a bag in a 5 gal round colman cooler w/3 gal of water. I believe I have about 1 gallon space to spare, so......Your gonna be pretty close to the top w/that extra gallon of water. You could reduce to planning on say 1.8 gallons into the bottling bucket and get three 6-packs of beer.

No need to sparge, only 6 lbs of grain you can press the heck out of the grain and get lots of high sugar wort out. I use two coffee cups w/the bag in a collander sitting on the cooler/mashtun.

I usallaly get at least 75% + so should U. I find that last wort I press out is really high in sugar. I get over 1/4 gallon out of that last pressing.

 

[FatsSchindee]

On the rackers.org website (here: http://www.rackers.org/calcs.shtml) there is a "can I mash it?" tool that calculates how much space the volume of the water plus the mash would take up. I use it when I question if something will fit! I don't BIAB, so I can't give specific advice on technique, but you can certainly do a mash and separate sparge.

Thanks for the link. Looks like I could do 6 lbs of grain at a 2.66 qt/lb ratio... Would be pretty full at 4.47 gal in a 5 gal pot, but since I'm just stirring, and not boiling or foaming up from break or hops, it could work if needed.

 

[FatsSchindee]

Here is some more information that may help you with mash and sparge volumes: http://woodlandbrew.blogspot.com/2012/12/when-more-grain-doesnt-add-more-sugar.html My book has more tables and further discussion.

Good info, thanks. So if I'm doing one sparge, it looks like 2 qt/lb is the best ratio for max efficiency. So that would be 12 qt or 3 gal. I would then use one gal for the sparge water to get to my total preboil vol (minus grain absorption). Does it matter in your table what kind of sparge (dunk sparge, though I could easily do the pour over a colander method, too) it is?

 

[FatsSchindee]

I often mash 6+ lbs of grain in a bag in a 5 gal round colman cooler w/3 gal of water. I believe I have about 1 gallon space to spare, so......Your gonna be pretty close to the top w/that extra gallon of water. You could reduce to planning on say 1.8 gallons into the bottling bucket and get three 6-packs of beer. No need to sparge, only 6 lbs of grain you can press the heck out of the grain and get lots of high sugar wort out. I use two coffee cups w/the bag in a collander sitting on the cooler/mashtun. I usallaly get at least 75% + so should U. I find that last wort I press out is really high in sugar. I get over 1/4 gallon out of that last pressing.

Good point, but if I wanted a full case of beer, though, I could just add the water after the mash, couldn't I? I mean, even if only using 3 gal for the mash (which looks like it may be ideal, according to Woodland's site), couldn't I either sparge with that extra gal or just even add it to the kettle pre-boil? After grain absorption, I should only have ~3.25 gal for the boil - which is perfect for my 5 gal kettle.

 

[RM-MN]

Good point, but if I wanted a full case of beer, though, I could just add the water after the mash, couldn't I? I mean, even if only using 3 gal for the mash (which looks like it may be ideal, according to Woodland's site), couldn't I either sparge with that extra gal or just even add it to the kettle pre-boil? After grain absorption, I should only have ~3.25 gal for the boil - which is perfect for my 5 gal kettle.

I'd suggest that you use that gallon (or less, I start with a bit more water than you planned, about 3 1/2 gallons) as a sparge step, not just add it to the pot. With all the squeezing you can do with BIAB, you still leave a significant amount of sugars in that bag of grain and you might as well make beer with it as to just throw it out.

 

[FatsSchindee]

I'd suggest that you use that gallon (or less, I start with a bit more water than you planned, about 3 1/2 gallons) as a sparge step, not just add it to the pot. With all the squeezing you can do with BIAB, you still leave a significant amount of sugars in that bag of grain and you might as well make beer with it as to just throw it out.

That's kind of what I was thinking too... Thanks!

 

[C-Rider]

Good point, but if I wanted a full case of beer, though, I could just add the water after the mash, couldn't I? I mean, even if only using 3 gal for the mash (which looks like it may be ideal, according to Woodland's site), couldn't I either sparge with that extra gal or just even add it to the kettle pre-boil? After grain absorption, I should only have ~3.25 gal for the boil - which is perfect for my 5 gal kettle.

Most likely. I've never been a "sparger".