BIAB: Calculating Volumes Properly?

[bradfordmonk]

In regards to doing BIAB:

I have a 44 Quart Bayou SS Kettle. I have a Sightglass installed, so there is an eyebolt towards top that really limits it to about 9.5 gallons at most.

If I have a grain bill of 16.5lbs. Will this fit in my kettle without doing a sparge? I am a little confused, really by the sheer amount of random calculators out there on the internet for different things.

I found the simple biab calculator, but i'm kind of confused. is the mash out volume just boiling water that i pour into the kettle after the mash time?

also, is this taking into account total volume...if it's telling me i need 8.89 total gallons of water, does that mean 8.89gallons of water AND 16.5 lbs of grain will fit in my kettle?

another thing to keep in mind is that i have a colander at the bottom of kettle to keep bag off bottom of kettle, but i guess if i'm not heating the kettle and just adding boiling water, i don't need the colander to protect the bag from being on bottom of kettle.

On side note, if the calculator doesn't take into account the total volume space, then can I put that extra 2.67gallons of 170* water in say a cooler and let it sit in there for 10minutes? i don't think 2.67 gallons of water is going to cover 16.5lbs of grain though.​

thanks.

 

[newnick]

I have the same kettle and use the same calculator and I've done 3 batches so far. I deselect mashout to get total amount of water needed and strike temp. I have the basket in my kettle and so far have had grain bills of 12 pounds or so. I've been getting a little over 8 gals. on the calculator as the amount of water needed and a strike temp of about 158.
What I've done is used 7 gal of water and brought it to strike temp, add grains and mash for an hour. I hit my mash temp within a degree. I then raise basket out and let it drain for a minute and then pour a gallon of water over grains to cool them down and then squeeze out most of the water. After boiling for an hour I get 5.5 gals or so into the fermentor with very little left in the kettle. So far I've hit my OG and ended up with about 53 bottles of beer after fermentation. Trying to keep it simple.

 

[bradfordmonk]

I have the same kettle and use the same calculator and I've done 3 batches so far. I deselect mashout to get total amount of water needed and strike temp. I have the basket in my kettle and so far have had grain bills of 12 pounds or so. I've been getting a little over 8 gals. on the calculator as the amount of water needed and a strike temp of about 158.
What I've done is used 7 gal of water and brought it to strike temp, add grains and mash for an hour. I hit my mash temp within a degree. I then raise basket out and let it drain for a minute and then pour a gallon of water over grains to cool them down and then squeeze out most of the water. After boiling for an hour I get 5.5 gals or so into the fermentor with very little left in the kettle. So far I've hit my OG and ended up with about 53 bottles of beer after fermentation. Trying to keep it simple.

okay, so when you put in 7 gallons of water, i assume the water level rises, correct? that's what i'm getting at, it seems like it doesn't take into account the expansion of the water from adding in grains; as that will take up more space.

 

[Jimmyjim]

I have the same kettle, with the strainer basket.

I brew 6 gallon batches
5.5 gallons into the fermenter = 5 gallons into the keg.

I just did a batch, 10 lb grain bill.

After approx 20 batches, I calculated grain absorption of .08 gals/lb.
1 Gallon boil off per hour.

No mashout. 60 minute boil. Lift the bag with a pulley, let it drain then squeeze.

7.75 gallons strike water. I go 5 degrees above my rest temp for
the strike temp.

Hit my OG number, 76% effeciency.

Try not to let the calculator confuse you.
It gave me to large of a volume initially.
Pushed my OG low for the first batch.

Cheers

 

[newnick]

I'm sure it does rise, I don't have a level glass. I don't really pay attention to level. I started with 7 gals. cause I didn't know if it would all fit. It fit without any problems, plenty of room. Then after mashing I new I needed the other gallon to cover boil off and the grain was hot in the basket so I sparged with the cool water, squeezed out the water and started to boil.

 

[newnick]

You might need a taller sight glass, I guess that's what your asking.
You could do a batch with a smaller grain bill and try to judge where you would end up with the larger bill.

 

[WoodlandBrew]

16.5 lbs of grain x 0.15 gallons displacement per pound = 2.475 gallons
16.5 lbs of grain x 0.2 gallons absorbtion = 3.3 gallons.

6 gallons pre boil volume + 3.3 gallons absorbed by the grain = 9.3 gallons of strike water (for no sparge)
9.3 gallons of water + 2.475 grain = 11.7(ish) gallons total volume in mash.

So that's too much for no sparge. You have a few options. Make a smaller beer. Make a smaller volume. Sparge. Top off in boil kettle.

What would be your preference?

 

[bradfordmonk]

How would I go about sparging...thats where I get confused with the process.

do I heat volume in another pot, and dunk grains in there, let sit, pull bag out and squeeze, add volume to kettle for pre boil volume.

or

heat volume in another pot, put grains in cooler, pour water over grains, sit for 10 minutes then squeeze, add volume back into kettle to reach pre boil volume?

guess that is more of a mash out. Problem I had was somehow hovering grains and pouring water over to rinse, grains expand out over the edges of the pot. So what's a good way to rinse?

 

[WoodlandBrew]

If you have two kettles big enough the first way you mentioned is how I would do it. If you are limited by a smaller kettle then you can pull the grains. Drip to dry. Empty the wort into a second kettle. Lower the grains and add more water.
The second volume of water should be the same as what you need to make up your pre boil volume. So if you had 4 gallons of runnings you would want to add 2 more gallons of space to make the 6 gallon pre boil volume. (because the grains are already saturated what you put in comes out)

Im not a squeezer. I just let it drip for about 20 minutes while I go do something else.

For mash out just put the heat back on after the saccharification rest. For sparge temperature is not as critical. That's one of beauties of BIAB.

 

[bradfordmonk]

hmm okay i think i get it. my thought process is just under 2 gallons of water enough to sparge and dunk the grains with/in?

thanks for help and responses

 

[WoodlandBrew]

There isn't a whole lot of space between the grains, and once the grains have already absorbed some water there is no where for to go. I was surprised the first time I added water to wet grains how quickly it covered the grains.

If you want to maximize your batch sparge efficiency you'll want to collect the same volume of first running as second runnings. That means 3 gallons sparge, and 5.5 gallons at dough in for 16.5 lbs of grain.

 

[weirdboy]

I always just put the full volume in as strike water. I don't get this whole "sparging" thing with BIAB. If I wanted to batch sparge, I'd use my cooler MLT. It's not rocket science.

I have a calculator that I created for no-sparge BIAB, which you can reference here. Also on the same page is a calculator for MLT volumes.

It is publicly shared, so looking at it now, I can see some folks were playing around with it and making notes in the margins, so to speak...so feel free to ignore those.

 

[bradfordmonk]

I always just put the full volume in as strike water. I don't get this whole "sparging" thing with BIAB. If I wanted to batch sparge, I'd use my cooler MLT. It's not rocket science.

I have a calculator that I created for no-sparge BIAB, which you can reference here. Also on the same page is a calculator for MLT volumes.

It is publicly shared, so looking at it now, I can see some folks were playing around with it and making notes in the margins, so to speak...so feel free to ignore those.

...becasue I don't have the kettle space to do full volume no-sparge with 16.5lbs of grain. If I had a 15-20 gallon kettle, sure I'd do it that way. and I'd do it that way if my grain bill was such that I could fit it all.

so i'm using the experience of the community to best decide how I can do this with what I have.

I do see your calculator. 9.32 gallons, might be pushing my kettle. What is your process...mash for the 60mins (maybe 90mins) then stir while heating up to 170*, let sit for 10mins, pull grain out, squeeze what you can, then boil on?

or i can to make sure to remove 1/2gallon for the lost, boil that seperately and add it after the mash.

 

[weirdboy]

But you DO have enough kettle space for all that strike and sparge water?

I must be missing something. If you are using two vessels, then just use one as a regular mash tun, and use the other as your HLT/BK. Don't do all this dipping the bag to sparge or other crazy nonsense. Do a regular AG process using one of the vessels as your mash tun.

I suppose the exception would be if you don't have a valve on the bottom of either vessel, in which case you HAVE to pull the bag out. If that is the case, do your regular mash in one, and heat the sparge volume to 170F in the other vessel. Pull the grain bag out of the mash, and put it into the sparge, and stir it around. Wait for the grain to settle, then pull the bag out and put it in a bucket, preferably suspended a bit so you can drain the bag while it's sitting there unattended. Combine the mash and sparge volumes into one kettle and bring to a boil, adding the runnings from the bucket as the BK is coming to a boil.

For calculating the mash and sparge volumes, use my calculator that I linked before for BIAB, because that will have a more accurate grain absorption rate. Your "water volume needed" will be the combined mash and sparge volumes. Take 5.5-8 gallons of that volume and designate that as your strike water, and then the rest will be sparge water. Remember that your wet grain will occupy about 1.3-1.5 gallons so that you don't overfill your mash vessel. If you have to mash thicker to make it fit, then do so.


If you only have one vessel, then you are going to have a really tough time. You maybe could use a bucket to sparge, or another possibility would be to do a sort of partial volume thing where you make a really high gravity wort, pull the bag out and then top off with water, but you are going to get pretty bad efficiency if you do that. Your best bet would be to scale the batch to a smaller volume to make it fit on your system, IMO.

 

[bradfordmonk]

in your calculator what are the Grain Volume and Water Absorbed Volumes?

Does your calculator take into account squeezing the bag? Because yes, going by your calculator looks like i'd be able to do it in my one kettle which fits 9.5 gallons. Doesn't leave me much play with the eyebolt from sightglass, but maybe i can put a oring on there to prevent leaking and go back up to 11 gallons before it starts dripping over the sides

 

[WoodlandBrew]

I agree with weirdboy for the most part. The only difference is my personal preferences are different. The bucket sparge looks like a good option.

If you are going for a 5 gallon pre boil volume, then like he said, It's pretty tight, but you wouldn't need a sparge. If you want a 6 gallon pre boil volume so that you can loose half a gallon to the boil and leave half a gallon behind to reduce the amount of protein going into the fermentor then it's either add a sparge or top off in the boil kettle.

The easiest way would be to just RDWHAHB and fill the MLT up just shy of the top. Then add a little more water at the end of the boil to make up the volume.

 

[weirdboy]

Grain volume is the volume that many lbs of grain occupies in the kettle. I guess you could call that the "dry" volume, although that's not quite accurate.

The water absorbed volume is the volume of water absorbed by that many lbs of grain. But in a BIAB system (or a regular mash tun, for that matter) that volume doesn't go away...it simply makes the grain volume expand by that amount as it is absorbed.


In a regular MLT, you are opening a valve to drain the tun, maybe tilting it a bit or whatever, but eventually the liquid stops flowing and that's what you're left with. In a BIAB you are typically squeezing the bag and doing other stuff to extract more liquid. So the BIAB uses something like .1 gallons per pound of water retained in the grain after the mash, whereas the MLT uses more like .12-.15 gallons per pound. So for that BIAB sizer to be accurate, you'll want to squeeze the bag.

 

[bradfordmonk]

Oh..that was throwing me off sine water absorption field doesn't change and was static no matter what amount of grains I put in.

 

[weirdboy]

Oh..that was throwing me off sine water absorption field doesn't change and was static no matter what amount of grains I put in.

Hmmm maybe someone fiddled with that cell. It shouldn't be a fixed number, it should be a formula. I will fix that.

 

[241]

I always just put the full volume in as strike water. I don't get this whole "sparging" thing with BIAB. If I wanted to batch sparge, I'd use my cooler MLT. It's not rocket science.

My approach too. Try/adjust, adjust/try til you get the results you want. All of these calculators confuse the hell out of me.

Focus on pre-boil volume. Start with around 7.75 gal for 5.5 gal batches and go from there. Notch a stick in two places or use your sight glass to make sure you have the volume you need after you pull the bag (notch #1 7.75) and after your boil (notch #2 5.5 gal).

I usually start with around 8.5 gallons of water pre-mash to account for grain absorption. If too much water is in the kettle after you pull the bag, boil more to reach your post-boil volume. If not enough pre-boil volume, add more water.

I'm usually at or around 75% efficiency with no sparge and with a mash out (raising temp to 170 and letting it sit for 10 mins). I've found the higher temp at mash out end makes the grains drip out a little more and bumps up my efficiency a bit too. Hope this helps.

 

[bradfordmonk]

alright, that makes sense. I'll give it a go. My kettle is 44 quarts, so it's 11 gallons.

so it will fit with about a gallon of extra space, problem is the eyebolt from the sight glass. i'll have to do some research on whether i can put an oring there to make sure it doesn't leak...or it may not leak at all to begin with as I've never filled it up that high since have sight glass put in.

 

[bradfordmonk]

thanks for help and suggestions.

 

[bradfordmonk]

i brewed today using the excel calculator posted earlier. gotta say it was really close with 16lbs of grain in an 11 gallon pot. probably wouldn't do that again. And figured I'd have to adjust a few of the numbers for myself sicne I have a colander in bottom and that takes up a little space.