BIAB advice.

That's an awfully big beer for a first outing. I'm guessing your efficiency would be about 50%, since efficiency falls with higher gravity, especially with BIAB, even if you ensure a really fine crush and squeeze the bag like mad. I'm thinking you'll need about 21 lb grain for 5 gallons. That is one heavy mash bag. You'll almost definitely want a pulley system to get the bag out of the mash unless you're only doing 2.5 gallons or something smaller like that, then cut what I say in half. But otherwise you might want to set your goal lower at 5-6% ABV and use only like 13 lb grain for 5 gallons, where you should be able to get at least 65-70% efficiency on the first go-around. The more gravity you want, the more grain you need to get there since efficiency tends to drop like a rock off a cliff above around 1.065. However...

To improve your efficiency significantly, you can incorporate a dunk sparge. Instead of doing a full volume mash, mash at a more typical all-grain batch ratio (like 1.5 qt/lb or so), and then for the makeup water after the mash is done to get up to pre-boil volume, get yourself a big kettle or tub full of the other half of your water and dunk the bag into it, stir well, then pull out again. You can easily improve your efficiency by 10-15% this way if 21 lb otherwise seems like an awful lot of grain, maybe you'll only need 15-16 lb instead of the 21 if you can sparge the bag. That or pour hot boiling or near-boiling water over the top of the lifted bag if you can find the capability to do so. This is way better than all the squeezing in the world.

Use water as hard as you want for an IIPA, and add gypsum on top of it. It's a forgiving style when it comes to water, you're likely to enjoy it no matter what.

Bottom line, I'm thinking you're either crazy enough to try what I'm talking about, or you'll want to dial back on either your ABV goal or batch volume. Maybe only make 2.5 gallons this time and bottle it. In any case, I wish you luck.

 

There's no way a mash efficiency of 70% for a 1.055-ish wort should drop to 50% for a 1.075-ish wort. Unless the bigger grain bill makes him not want to hoist the bag long enough to completely drain it. Efficiency will of course be lower, but not by anywhere near that much.

OP: BrewCipher actually has a calculator for estimating the efficiency change. Other programs might too, but I don't know. But since you've never done BIAB before (and thus your technique probably won't be awesome yet), I would recommend assuming something like 65% mash efficiency for the smaller beer, dropping to about 60% for the bigger beer.

I would suggest not adding carapils to an IPA, especially a big IPA, unless you want a thick mouthfeel (not typical of the style).

 

I regularly get 80-85% conversion efficiency doing BIAB and get 6%+ beers easily from a 10-12 pound grain bill in a 5 gallon batch. If you have a smaller kettle that cant handle over 12 pounds grain, then you want to use another fermentable source to get up above 7%...I use honey most of the time because its less processed and is completely fermentable, which in a higher abv beer, I like to dry it out a little any way.

To achieve the efficiency I get, I...
1. Do extended mashes between 90 minutes and 6 hours depending on grain bill and what my day looks like
2. Wash/sparge grains with mash out temp water (170) and squeeze the bag after every approximate 1.5 L wash until you reach your initial boil volume...I generally wash/sparge with 6-10 liters of water and squeeze the bag like it owes me money around 4-8 times to collect my preboil volume

I havent gotten below 80% conversion efficiency with this method in a couple of years and have been extremely satisfied with all of the beers I've made this way.

With 70% efficiency, you can get a base abv of a little over 7.5% with 15 pounds of 2 Row and then whatever else you add will up the abv, or if your kettle maxes out around 12 pounds, add a little over a pound of honey/dextrose and you'll be up around the same 7.5%.

 

1) Use some software to figure out your weights/percentages. Money well spent.
2) Simplify your DIPA recipe. You don't need (want) rye, MO and Carapils all in one beer. Especially for a DIPA. You want this thing to finish bone dry. Pick one of those to feature with your base malt and supplement some cane sugar to get the gravity where you want it.
3) I'd guess you could start around 68%-70% efficiency for your first time BIAB for a DIPA this size (also assuming your adding sugar at the end of the boil = less grain in the mash). Make adjustments going forward from there.
4) Most novice brewers want IPAs/DIPAs that are crazy over-the-top hoppy but don't want to pay for the hops to do it. You can, but you won't be happy. Plan for a ton of dry hops.

Good luck!!

 

To the OP, I haven't seen any issues brewing anything with BiaB as opposed to a three tier system. With that said, I would recommend starting with something smaller for your first all grain brew. Maybe a simpler, smaller IPA, even. That will be much easier to manage until you get the process down. Just my 2¢.

This post is relevant to me, as a guy my wife works with wants to brew a barleywine recipe on my BiaB(asket) system. The biggest beer I've brewed to date is the AP NEIPA (with some modifications), which came out at ~1.070 with, IIRC, ~15# of grain. Not sure how feasible a barleywine is without adding extract or something. Thoughts? My kettle and grain basket (my alternative to a bag) are surely big enough for a five gallon batch at 15 gallons, but otherwise, should I be okay?

 

I usually hit ~7.75% ABV when BIAB'ing IPAs with about a 15llb grain bill.

For the water, you need to know what you currently have and adjust accordingly, (if at all).

 

I also get about 75% efficiency most of the time, and I typically make beers that are at least 7% (sometimes by accident ). I usually extend the mash to 75-80 minutes, but if I was making a really big beer I might give it 90-100. Your results will probably depend on the kind of crush your grains have, though.

 

Like people above, I usually get 75-78% efficiency by (1) having the LHBS double-crush the grains (no concern about a stuck sparge); (2) mashing for 75-90 minutes; and (3) "sparging" with 175-degree water. For 5 gals at that OG, my process would be to mash with 7.5 gals water, leaving 6+ gals after pulling the bag (and squeezing/pushing on it with a mash paddle) and then sparging up to pre-boil volume, assuming a few points lower on the efficiency.

 

I've been doing allgrain for 10 + years but started playing with biab in the last 8 months. I don't have it dialed in but my efficiency is lower. I recommend brewing your recipe but keeping some pal dme on hand to boost your gravity if needed