High ABV BIAB - Need help

[bolus14]

I'm sure there are some easy answers for this, and I think I know the most obvious, but first the background and my plans.

I have basically been getting 62% efficiency on all my brews, from recipes with 10lbs of grain up to 16lbs over about a year of doing BIAB. I have always just done single crush at LHBS and have tinkered with changing a few other things to increase eficiency, less water for mash, pouring 170 degree water over grains after the mash just to throw a couple out there, none of these attempts has really changed my efficiency.

I'm now looking to make Denny Conn's BVIP and this Imperial Stout: https://www.homebrewtalk.com/f68/double-w-imperial-stout-74932/

I'm planning 4 gal batches, that is 4.25gal into the fermenter, to help with making sure I can fit the volume in my kettle, I use an 11gal Bayou Classics pot with a strainer, with the strainer I don't have to worry about the weight of the grain busting the bag. I really want to hit as close to the OG on these and make them come out correctly.

My questions:
1. Should I not change anything this go round and just plan around my 62% or should I double crush my grains? I could also ask if LHBS is willing to close the crush gap, they're usually not busy and are pretty laid back so they might be willing to do this.
2. If I do double crush how much of an increase would you plan for an increase in efficiency? I know this is very subjective, just looking for ballpark ideas.
3. Any ideas if I'll be pushing the volume of my kettle? With planning for 62% efficiency the stout which needs 19.6lbs of grain by my calculations. Using the volume calculator spreadsheet from biabbrewer.info I'll need 8.47 gallons of water. I think that strainer take up about .5gal of volume which only leaves 2gal of volume for the grain.

Any thoughts on approaching this? I was thinking of using 6.5 gal of water for the mash, then heat 2 gal of water to 175 towards the end of the 60min mash, lift grains out of kettle, let drip, then drop the bad into the 175 water, let soak for 5 - 10 min and transfer that wort to the main kettle.

 

[Shawn_Brewin]

been brewing BIAB Style for about a year now and have been using a buddies mill and only single crushing my grains and getting effiecencies of about 72-75% I recently purchased my own Mill and after my first Batch, i got an efficiency of only 64%. The mill came factory set at 39 thousandth's of an inch (1mm), i don't know the exact setting of my buddies but i know it is tighter. I didn't have a feeler gauge to set in my mill tighter, so i tried just double crushing my grains the next time and got 72% for my efficiency!

So in my experience i got to say that the double crush seems to help. it was the only factor i changed and i got a 8% jump in my efficiency. hope this helps.

 

[Oginme]

With that low of an efficiency, I would start by double crushing. Shawn's observation of about an 8% increase in efficiency is about in the ballpark for most people I've talked to. In doing a high gravity BIAB, you should expect a lower efficiency anyway due to the higher grain bill.

If you think you are going to be too high in your kettle, I'd sub out some of the base malt and make it back up with light DME. I always keep some on hand for small corrections in initial gravity (in addition to yeast starters).

 

[wilserbrewer]

Two things that I feel are essential to higher efficiency BIAB,

1. A full volume mash with a bag that fully lines your kettle.
2. A good crush of the grain.

Respectfully, I would look to correct the above prior to getting much further down the rabbit hole.

20 lbs of grain is nothing for a properly constructed bag....
https://www.homebrewtalk.com/f11/biab-polyester-voile-strength-test-384445/

 

[Davemci]

I use biab and I pull it out and let it drip twice. The second time I use a 165 deg 1 gal Sparge over the bag. I also squeeze the **** out of the bag at the end. My last efficiency was 80% ish. Before I did those steps my eff was around 65% also. I do full volume boils also.

 

[Conestoga]

You could mess around with a longer boil time, this way you can start out with more water (which will improve kettle efficiency). Obviously you will have limitations due to kettle size, but it's a thought if you have some wiggle room.

 

[bolus14]

Thanks. At this point do to the larger grain bills on these two I'm going to plan for 65% efficiency(3% increase), i don't want to figure a full 8% increase and i'll double crush the grain.

In the past i've "squeezed" the grains by pushing as hard as i could wish my mash paddle with the straining basket and bag hanging over the kettle, bottom 1/4 or so of the strainer still in the kettle so wort didn't drip out. When you guys are squeezing the bag(insert joke), are you just spinning it around to create the squeeze or literally squeezing with your hands?

Wilserbrewer - I have a bag I ordered from you, done 12 batches so far. So, I trust it'll support the 20lbs grain bill. Is the drawstring strong enough for this grain bill to hang it from the pulley's you sell too?

 

[wilserbrewer]

Yes, the drawstring is plenty strong, approx 200 lbs break strength.

If you just let the bag drain for 20-30 minutes, there won't be much wort left to worry about squeezing etc.

I like to just let it hang over the kettle while the wort comes to a boil.


Wilserbrewer
Http://biabbags.webs.com/

 

[Rdom]

After addressing your crush, you should look at your water. I was getting efficiencies that were all over the place (65 to 82%) before I started estimating my mash pH and reducing it with acid malt (2% of the grain bill), gypsum, and calcium chloride and by diluting my tap water with distilled water. Now I've settled in at 72-75% efficiency. My grain bill sizes are fairly average.

 

[DonH]

Squeeze the piss out of your bag! adds trub but that falls in the carboy especially if you cold crash Now, one method instead of hanging your bag is to take two home depot bucket, one with holes drilled in it on the bottom like a strainer basket. Place your bag in there and let it drip, then you can squeeze it out

 

[bolus14]

Yea at this point i'm not worried about trub from squeezing, I have always pressed the grains with my mash paddle for at least 5 - 10 min until it seemed like the dripping had more or less stopped, then waited another 5 - 10 to let the remaining wort drip out.

I really think my main problem is the crush on the grains, so when I pick up my grains, this week hopefully, I'll be sure to do a double crush. I'm also planning to testing my mash pH this time, if I had to guess I'm sure i'm not in the optimal range. I know I have hard water and have looked at using a couple spreadsheets to figure out if I need to add anything to make my water better, but haven't had much luck. The online report from my water board seems to be missing some info and I just haven't called them to see if I can get the info that's missing.

In the end I only want to change one thing at a time in hopes of pinning down whether it's one thing causing my low efficiency or a combination, I think it's a combo but better to know how much each is contributing if that's the case.

 

[bolus14]

I may have found another part of my problem, my thermometer

I'm not 100% sure yet but last night as I was moving a starter to my fridge I noticed my thermometer showing 90 degrees in the room where I had the starter, no way it was 90 in that room, 80 tops and if I had to guess I would say it was more like 75. My last couple batches seemed like they took longer for me to get down to pitching temps but I chalked it up to higher water temp from my tap going through my chiller because of the outside temperatures right now.

So, now I'm looking to find a good thermometer quickly, or else I'm putting of brewing this weekend. No way im going to brew with a good possibility that my thermometer is that far off, even if it's 5 degrees off that's a lot when I'm planning to make a RIS, need the mash temp to be pretty accurate for this one!

 

[BlueHouseBrewhaus]

Double crush was the biggest efficiency jump for me - about 8%. I also do a slow sparge through the raised grain bag - about 5% increase. A turkey basket and pulley system helps that. I get about 80%.

 

[wilserbrewer]

So, now I'm looking to find a good thermometer quickly, or else I'm putting of brewing this weekend.

FWIW, I have found the digital stick thermometers available at most big box stores to be inexpensive and fairly accurate...having two is a plus, check at boiling and at freezing with as much crushed ice as you can pack in solution if an insulated or plastic cup...

example....
http://www.walmart.com/ip/38241739?...03553379&wl4=&wl5=pla&wl6=79191255139&veh=sem

I even bought one of these for a backup spare....for only $2.72 shipped it seems pretty darn accurate....
http://www.ebay.com/itm/Digital-Coo...870?pt=LH_DefaultDomain_0&hash=item233cf11cce

 

[ram5ey]

The three biggest factors in BIAB efficiency as far as my experience and research has taught me are:

1- crush. I have a bunch of flour in my grist...not a ton but a bit more than most 3v guys would care for...no biggie though because you can't get a stuck sparge with BIAB.

2- water to grain ratio. The thinner your mash the better your efficiency will be. I find the 2.3-2.6 range to be the sweet spot but that is definitely not the most realistic goal for big beers unless you want to boil for hours. I consistently hit around 85% for 1.055 beers and and 70% for 1.065 beers.

3- water chemistry. PH can totally screw up extraction for the mash. So if the first 2 don't help look at your water and make some adjustments.

 

[mbbransc]

The three biggest factors in BIAB efficiency as far as my experience and research has taught me are:

1- crush. I have a bunch of flour in my grist...not a ton but a bit more than most 3v guys would care for...no biggie though because you can't get a stuck sparge with BIAB.

2- water to grain ratio. The thinner your mash the better your efficiency will be. I find the 2.3-2.6 range to be the sweet spot but that is definitely not the most realistic goal for big beers unless you want to boil for hours. I consistently hit around 85% for 1.055 beers and and 70% for 1.065 beers.

3- water chemistry. PH can totally screw up extraction for the mash. So if the first 2 don't help look at your water and make some adjustments.

#2 and #3 kind of go hand-in-hand, don't they? If you are using that high of a water:grain ratio, your PH is going to be pretty high, right? Are you throw some acid malt in the grist too?

I'd suggest looking at #1 first. Tighten up the mill as much as you can. So what if there's flour in there. I have a bunch of flour in mine. Doesn't cause any issues with BIAB.

 

[Oginme]

#2 and #3 kind of go hand-in-hand, don't they? If you are using that high of a water:grain ratio, your PH is going to be pretty high, right? Are you throw some acid malt in the grist too?

Not necessarily. My water is pretty poorly buffered and I can do a full water BIAB on most recipes without having to worry about the pH. It seems to wind up in the 5.3 to 5.5 range consistently. Others I have talked to are not so lucky and have to add acid or salts to get the pH in the proper range.

 

[bolus14]

Got my grains yesterday and picked up a new thermometer.

Double milled the grains and there's a noticeable difference in how much flour there is, so hopefully that will help with almost 20lbs of grain. I'm also planning to put 1.5 gal or 2 gal of 185 degree water into a separate pot/bucket and "soak sparge" for 10 minutes, then pour that back into the main kettle. I'm looking ot finalize all my water numbers today and hopefully brew tomorrow or Sunday. Brew day partly depends on when the yeast settles in my starter, it's been in the fridge for almost 24 hours now.

The thermometer I picked up was an oneida from Bed Bath and Beyond, http://www.bedbathandbeyond.com/store/product/oneida-digital-thermometer-with-timer/120845. I found it was mostly accurate but took up to a minute to get the right temp. Also, doing a big temp swing like going from a cup of crushed ice slurry to 65 degree water ddin't always read correctly. So, this one is going back to the store today.
Now i'm looking at this one, http://www.bedbathandbeyond.com/sto...ad-thermometer/1016313882?Keyword=thermometer, or maybe picking up a couple of $5 ones and hope they read correctly for a couple brews. At this point i'm convinced of going to something thermawokrs make, might be a thermapen might not, but right now it's a timing thing. I need something for the weekend so I'm stuck getting what I can get locally.

 

[ram5ey]

Yeah I the only adjustments I've ever needed to do were to either just add some gypsum/calcium chloride, or to add roasted grains later in the mash.

 

[Allergic2hops]

I have a Wilser BIAB and it is fantastic, very happy with it. If you are using the grain sock for your LHBS you may want to upgrade. The clarity of my beer is off the charts without cold crashing. Also I have extended my boil time in some cases to 90 min if I suspect the grain to be older and consequently drier than normal. My efficiency hits around 80 -82% usually.

 

[bolus14]

Brewed this AM, didn't hit OG because of a few mistakes that could easily be fixed. Preboil OG was 1.071 which was on target for what I needed, planned for 4.25 gallons which would've put me at 1.117. Ended up with a touch over 5 gallons which is why i missed the OG.

Now the mistakes. I ended up getting 7 gallons after mashing and "dunk sparging," which is more than I expected so the grains didn't absorb as much as I planned for, I squeezed more than I usually do and let it drip out more than usual too. After that I planned to boiled for 90 minutes instead of 60 to account for the extra wort. Well, kids ended up distracting me more than usual and I forgot about boiling longer. If I had boiled for the extra 30 min I would've boiled off an extra .5 gallons at least putting me right around 4.5 gallons, just .25 gallon over what I planned for.

In the end I should end up with around 12 more bottles than I planned for, clocking in at about 8% ABV. Not horrible and my mistakes can easily be fixed.