Why does BIAB require so much water for mashing?

[Kevin79]

I've been doing 5 gallon partial mashes as of late. Love doing them and want to start getting my hands into all grain. BIAB seems the obvious way to go as I already have everything I need. I want to start doing 2.5 gallon all grain batches as I only have a 5 gallon kettle.

When doing a partial mash, the general rule is that your mash be at about 1 to 1.5 quarts of water per pound of grain. The whole concept of calculating boil off and adding all of your water to the mash seems excessive to me, as if it would be detrimental to the grains or something. I know it's obviously not, since that is what people do. I guess I'd just like to know the reasoning for doing so, and why does partial mashing stick to the 1 to 1.5 quart ratio?

 

[tmendick]

you can mash with the same qt/lb in BIAB, but it's just simpler to add the full volume so you don't have to sparge. Personally I've done 25-30 BIAB batches and the last 5 or so I've started to do dunk sparges with lowers the amount of mash water.

 

[Roundhouse]

The one thing that many overlook with biab is that if you are adjusting your water ph, the grains will buffer that ph more at lower water volumes than it will at higher dilution rates. You may find that your ph falls out of an acceptable range with one quantity of water but not with another so watch for that. It'll effect your extraction efficiency. Depending on your grain profile this may not be an issue though.

 

[Oginme]

The original concept of BIAB is to do the mash and boil in one vessel, saving time and cleaning. The total volume needed for the boil and grain absorption would be added to the kettle and then the grains and bag added when the strike temperature is reached. The result is that there would be no topping off of water needed.

 

[kh54s10]

When I do BIAB I use about 1.25 qts per pound of grain. I then do a sparge. I have the bag in a colander over the pot and pour ~168 degree water over the grains until I collect my preboil volume.

 

[Kevin79]

When I do BIAB I use about 1.25 qts per pound of grain. I then do a sparge. I have the bag in a colander over the pot and pour ~168 degree water over the grains until I collect my preboil volume.

This is what I'm planning on doing. That and a good bag squeeze afterwards.

 

[rekoob]

I don't BIAB, but I find the process interesting.

I like the idea of the colander with the bag in it for sparging. do you leave the bag open so you have better access to the grain?
I would think letting the colander sit for a bit, kind of like a lid would allow pretty much all sparge water to drain without the bag squeeze.
If that's the case, I like the idea for doing extract kits that come with grain, seems like this would work well for that also.

 

[ram5ey]

In BIAB your efficiency is very closely tied to your water to grain ratio. You will get better efficiency with a thinner mash and less so the thicker it gets. This is why BIAB brewers will notice a drop in efficiency when doing higher gravity beers. Sparging will only dilute the extract that you already pulled based on that grist ratio as it isn't helping to do anything other than rinse the grain. If you go with something like 2.3 - 2.6 qt/lb you will see great efficiency with out sparging (with a good fine crush) but remember to squeeze the bag.

 

[rekoob]

Okay, so I have to ask, how does everyone squeeze the bag?
Just thinking of the last brew day at a friends house, he just started brewing and is doing extract with steeping grains. He was doing it out side so had no way of hanging the bag over the BK. I used to do this and let it cool a little before I attempted to squeeze out what I could. Needless to say it's tricky to squeeze the grain bag at mash temps.

 

[CUrchin]

Okay, so I have to ask, how does everyone squeeze the bag?
Just thinking of the last brew day at a friends house, he just started brewing and is doing extract with steeping grains. He was doing it out side so had no way of hanging the bag over the BK. I used to do this and let it cool a little before I attempted to squeeze out what I could. Needless to say it's tricky to squeeze the grain bag at mash temps.

I put my bag in a large colander, and put the whole thing on a grate that sits over the pot. After draining for a bit, I take a plastic plate and push down on the bag/grain. Work well.

I personally do a "sprinkle sparge" (pour water over the bag roughly at the same rate it is draining from the bag) and do not do full volume. I don't usually squeeze until I am near the end of my sparge. Good luck.

 

[bullinachinashop]

Another idea that works well is to use your bottling bucket.
Start by mashing @ 1.25 qt/lbs. After conversion pull your bag, give it a squeeze and then put it into your assembled bottling bucket. Add the balance of total water needed at mash out temps, stir and then run off into your boil kettle.
This is a very simple, single batch sparge without having to worry about PH issues as much.

 

[mb82]

I usually sparge with about a half gallon of water, just enough to cool the grains down to something that I can handle. Then I twist the bag a bunch of times to get it tight and squeeze it like it owes me money.

 

[Pkrd]

Silicone oven mitts are good for squeezing. I don't bother with that now, I sparge if I need to pick up a few points.

 

[Cheesy_Goodness]

+1 for colander (just make sure the %*(#ing thing can't fall into your collection vessel and splatter wort all over the kitchen) and squeezing. I do sparge from time to time, depending on boil volume.
I usually let it drain, squeeze/press it, then flip the bag on it's side and do the same thing, keep rotating for a bit, then open up the grain bag and mix up the grains, since most of the inside is still pretty moist. Keep doing as necessary.

 

[wilserbrewer]

I like the idea of the colander with the bag in it for sparging. do you leave the bag open so you have better access to the grain?

While you can open the grain bag for sparging, I have found that the sparge water easily goes right through the top of the bag. The bag is so porous, that one can sparge right through closed grain bag.

I would think letting the colander sit for a bit, kind of like a lid would allow pretty much all sparge water to drain without the bag squeeze.

Everyone loves to squeeze the grain bag, it seems so productive when the bag is saturated right after being removed from the kettle. I have found that patiently letting the bag drain will get almost all of the wort with very little left to squeeze out. For me, squeezing the bag is not worth the effort, just let gravity work it out.

Another idea that works well is to use your bottling bucket.

At the risk of appearing a nit picker, I would advise against using your bottling bucket for anything preboil.

The mash is loaded w/ lactobacillus, best not to "infect" your bottling bucket every brew session. Yes, I realize you will sanitize prior to using as a bottling bucket, but it is not advisable to mix equipment pre boil and post boil for best sanitation practice. JMO, you want to keep your cold side equipment as clean as possible, best practice to find another bucket to use...

 

[Pole]

Okay, so I have to ask, how does everyone squeeze the bag?
Just thinking of the last brew day at a friends house, he just started brewing and is doing extract with steeping grains. He was doing it out side so had no way of hanging the bag over the BK. I used to do this and let it cool a little before I attempted to squeeze out what I could. Needless to say it's tricky to squeeze the grain bag at mash temps.

I picked up two 5g buckets and drilled a bunch of 1/4" holes through the bottom of one of them. Put that bucket inside the non-drilled bucket and simply put your bag into the nested buckets at the end if your mash.

I "squeeze" by using my big ass potato masher (makeshift mash paddle) to push down on the bag while it's in the bucket. The wort drains through into the lower bucket and I can usually collect another 2" of wort.

 

[Cathedral]

I just ratchet it up and let it drain into the pot. If I'm feeling extra sassy, I'll twist it and let it squeeze itself.

I've done full volume BIAB my last six or so batches. I love only having one vessel and a few buckets to clean, and I get every bit of efficiency as I did when I was doing a three-vessel system.

 

[DaNewf]

I dunk, rinse and squeeze.

I mash/boil in a 5 gallon pot to get a ~3.5 gallon final volume. As the mash winds down I heat my dunk sparge water in a second smaller pot. While the bag is dunking I use my electric tea kettle to heat a half gallon to 170F. After the dunk sparge is complete I use a colander and plate to squeeze the ever loving crap out of the bag. Then using the water in the tea kettle I do some rinsing and maybe some gentle squeezing to finish topping off the brew pot which is already on the stove heating up.

 

[Flboy]

Sub'd

 

[djt17]

I picked up two 5g buckets and drilled a bunch of 1/4" holes through the bottom of one of them. Put that bucket inside the non-drilled bucket and simply put your bag into the nested buckets at the end if your mash.

I "squeeze" by using my big ass potato masher (makeshift mash paddle) to push down on the bag while it's in the bucket. The wort drains through into the lower bucket and I can usually collect another 2" of wort.

This is exactly what I do...minus the big ass potato masher. I use my mash paddle.

 

[C-Rider]

Don't fear the squeez. If you do small amts like less than 7 lbs it's bretty easy to place the bag in a collendar over something to catch the wert and then using two coffee cups like in the picture go for it squeeze every last drop out. No burnt fingers, no sticky gloves.

[url=https://www.homebrewtalk.com/photo/pressing-the-grain-bag-57084.html] [/URL]