BIAB - Amount of Water.....

[bfriend54]

I have brewed 2 batches now with the '3 Gallon' BIAB kit from Northern Brewer. The kit consists of a 7.5 Gallon kettle and a BIAB bag.

The directions for their 3 gallon BIAB ingredients kit call for starting with 5.5 gallons of water...

Seems to me this is really excessive for a 3 gallon batch of beer.

In my two batches that I brewed so far, (using my own ingredients from scaled down recipes from a local homebrew supply), I started with about 4.7 gallons of water...

The first batch was a 90 minute boil and I had more wort than I needed and the 2nd batch was only a 60 minute boil and I had way more wort than I needed. I had enough for 4 gallons and still dumped some down the sink...

For the 2nd batch I really squeezed the heck out of the bag so I didn't leave much water left in the grain bag.

That..coupled with a 60 minute boil..which I kept an eye on not to boil over...so it was more of a soft rolling boil, compared to something more on teh edge... and I kept the lid on the kettle during the boil....

The end result was I didnt lose that much water due to evaporation or in the grain bag....

The beer is not done yet but I did measure the OG which was about 1.05 which should result in a porter with about ABV 5.5% or so. I was shooting for a more robust porter.. The amount of water diluting too much....

Anyway....This whole topic has got me thinking about Why should BIAB attempt to mash with the full boil amount of water????

Why not use only a lesser amount of water during the mash and the boil and then just top off the final boiled wort with clean cold water to get the batch to the right amount??? What's wrong with that line of thought?

Thx....

 

[Gravedigger]

Never done a BIAB but I know that youd boil without the lid. The boiling drives off unwanted compounds such as DMS and if you leave the lid on the compounds go back into the wort. I've also read that you should be carefull when squeezing the grain bag so you don't extract tannins. Can really comment on that though since I've never done BIAB. If your beers are turning out ok without off flavors using you current process then ignore everything I've just said but the combination of no lid and less squeezing may reduce your final volume closer to what it should be.

 

[Beer-lord]

I've found the BIAB Calculator to be pretty accurate (bottom of the page)

As for squeezing the bag, for the last 4 years I've squeezed the bajeezus out of my BIAB's and never had a problem. The tannin problem is over-rated and likely due more to the mashout at higher than 170 degrees...just one man's opinion who does lots of these and folks love my beer.....just sayin'.

 

[Gravedigger]

Thats good to know. I do traditional all grain brews but someday might try BIAB and was wondering about the bag squeezing/tannin thing

 

[Brewbien]

I've found the BIAB Calculator to be pretty accurate (bottom of the page)

As for squeezing the bag, for the last 4 years I've squeezed the bajeezus out of my BIAB's and never had a problem. The tannin problem is over-rated and likely due more to the mashout at higher than 170 degrees...just one man's opinion who does lots of these and folks love my beer.....just sayin'.

I use the same calculator and it works great.

You definitely want to leave the lid off while you are boiling. Boiling serves 3 purposes, sanitation, hop utilization, and driving off DMS precursors which cause off flavors in your beer.

The reason for full volume mash/boil is that it is the easiest way to improve the quality of your beer. Also, you will get a more accurate gravity reading than if you were to top up with water later. This will allow you to have more control over your setup as you start getting more consistent and get into more complicated brews.

As for squeezing the bag, I used to do it but I always made a mess so now I have a strainer that I let it drain in and add that wort back into the boil pot and just adjust my recipes for a lower efficiency.

Hope this helps.
Cheers!

 

[bfriend54]

Beer Lord...thanks for that link. Does the grain absorption amount come out right even after squeezing the bajeezus out of the bag? Just wondering how much that will affect it. Looks like a big part of my problem was boiling with the lid on. I won't do that again... Thx

 

[paraordnance]

The beauty in BIAB is that you absolutely don't have to start with exact amount of water. You dont even need BIAB water calculator for that matter. I make 5.5-6 gal batches and I always start with 6 gal of water regardless of the grain bill and boiling time or any other variables.

 

[bfriend54]

One thought I had about this was if you boil less wort and then top off with cold water it helps cool it down faster too

 

[drksky]

I've done all four of the NB BIAB kits and have been withing tolerance of the 3-gallon batch size every time starting with 5.5 gallons. As stated above, boil with the lid off, otherwise you won't get any evaporation and all the nasty stuff you want to boil off just drips back into the pot.

 

[Beer-lord]

Beer Lord...thanks for that link. Does the grain absorption amount come out right even after squeezing the bajeezus out of the bag? Just wondering how much that will affect it. Looks like a big part of my problem was boiling with the lid on. I won't do that again... Thx

I use beersmith and adjusted a few things so that I'm always very close to where I should be. I try not to worry about the little things. If I have lots of grain for my pot, I add extra hot water like a mini sparge and it not only brings my water to where it needs to be, it gets all the goodies from the grains.

 

[RM-MN]

Start with something simple. If you boil with the lid off for an hour, you will boil off about 3/4 gallon of water if you are careful not to boil too hard. That means you need to start your boil with 3 3/4 gallons of wort. Suppose you only started with 3 3/4 gallons of water and mashed the grain in that, then squeezed the bag of grains out. You will lose a little of the water to grain absorption but not much, so just pour that much more water through the bag of grains as a pseudo sparge and add that to the boil pot so you now have your 3 3/4 gallons of wort. It works well for me and that pseudo sparge step picks up another 5% efficiency, sugars that would otherwise be thrown out with the grains.

 

[Cider123]

I was originally surprised how much strike water was needed to do a true, no-sparge BIAB. I make 5-6 gallon batches and originally had a 10 gallon SS pot. I found that I could not add all the water needed. I had to either sparge or top off after mashing because of my kettle capacity. I then upgraded to a 15 gallon kettle and can now BIAB with ease. In fact, I have enough headspace that my hot break rarely reaches the top of the kettle.

I brewed a low OG beer last week that only had about 7.5 pounds of grain and still my strike water volume was 9.4 gallons. After grain absorption, evaporation and trub loss, I got about 5.5 gallons in the fermentor.

I learned a lot about brewing in general from learning how to BIAB. I highly recommend the site BIABrewer.info to anyone that is interested in BIAB. Those folks know the scientific ins and outs of the process. Silly brewing myths will be debunked for you, so enter with an open mind.

After learning and using their FREE BIABacus spreadsheet I threw my copy of BeerSmith in the closet.

 

[zacster]

I use a 10 gallon pot for 5.5 gallon BIAB batches and have no problem at all. My last batch was 15 pounds of grain and it fits with room to spare. I'm not by my computer with Beersmith so I can't tell you what my starting water volume was, but in the end I was able to let a lot of trub settle in one carboy before I racked to a second carboy where I added the yeast. I still ended up with 5.5 gallons.

 

[bigdongsr94]

Keep in mind it's all about how you brew. People get different numbers. Squeeze away and don't worry about it and boil lid off. The thin mash if full volume helps to raise you efficiency under normal circumstances. The best data is your own data and second would be the people doing the exact same kit in the same setup. I would brew again per directions and take notes of volumes. Make adjustments after because the lid off is a big change.

 

[buzzerj]

I've done a bunch of BIAB batches primarily because the stove I boil on doesn't put out a lot of heat. I can't get 5 gallon plus volumes to come to a good boil. So I switched to BIAB using a 4 gallon starting volume. I get a good boil with that volume and boil with the top off. I don't squeeze the bag too much prior to the boil, I just let it drip down. Most of the sugar comes from my extract addition anyway. After boiling, I'm usually down to 3 gallons of wort for the fermenter and I top it all off to 5 gallons and it turns out fine.

 

[jason91notch]

Great info here.
Ive got one question- Does the BIAB calculator Beer-lord mentioned account for grain displacement? For example, if I enter 8lbs of grain, 1hr boil time, and 3 gal final volume, it gives me 5.00 gal of strike water. So, does this mash take up exactly 5 gallons worth of space? If not, how do you calculate for grain displacement? This would be helpful in figuring out if you have enough room in your kettle to mash what you want.

 

[pdxal]

There's a mash volume calculator here, BIAB or not:

http://www.rackers.org/calcs.shtml

 

[jason91notch]

Thanks pdxal. So that calculator calculates mash volume with strike water... so to get total kettle volume in your BIAB mash, you would need to take that number, plus grain absorption, plus boil off, and that would give you your total volume needed?
Using my first example of 8 lbs of grain, that calculator says the mash will take 3.14 gallons of space. Then add .10 gal/lb of grain, which is .8 gal, plus another gallon for boiloff, comes to a grand total of 4.94 gallons needed. from start to finish. correct?

 

[william_shakes_beer]

I have done many biab batches in my 15 gallon boilermaker. a 5 gallon batch I add all the water at strike time ( final volume plus boiloff plus absorption) when I do a 10 gallon batch I need to mash and sparge, since the kettle isn't big enough for the bigger volume plus the bigger grain bill.

I found on another thread a cool way of getting the best out of the bag withoug burning my fingers. I bought a 5 gallon homer bucket which I drilled with a bunch of holes on the bottom. This gets set into a 7.5 gallon fermenter bucket. The bag comes out of the kettle after the mash is done and the weight of the grains squeeze the last of the wort into the void between the 2 buckets. If I need to sparge I just pour another supply of warm water over top of the bag as a sparge. The graduations on the fermenter tell me exactly how much volume have available.

 

[1MadScientist]

You do want to use the full volume of water at the start, if your pot is big enough.

What is the estimated OG?

What is the weight of the grain bill?

 

[Forrest-hunters]

https://www.homebrewtalk.com/f36/biab-strike-water-volume-temp-more-413374/

I just created the above link with an excel spreadsheet today and have updated it since I originally posted it. I have add ABV, ABW, calories and more too. I will post it tomorrow. Haven't tried it yet but it is based on numbers I used last summer when brewing. Let me know how it compares to you or if I need to add or delete anything.

 

[pdxal]

Thanks pdxal. So that calculator calculates mash volume with strike water... so to get total kettle volume in your BIAB mash, you would need to take that number, plus grain absorption, plus boil off, and that would give you your total volume needed?
Using my first example of 8 lbs of grain, that calculator says the mash will take 3.14 gallons of space. Then add .10 gal/lb of grain, which is .8 gal, plus another gallon for boiloff, comes to a grand total of 4.94 gallons needed. from start to finish. correct?

Give or take, yes.
I figure a boil off rate of 1gal/hour, mash very thin 2-2.5qts/lb (the whole idea behind BIAB), grain absorption of 0.1gal/pound but usually get much more wort out because of draining/squeezing the bag tons. You can always boil off longer to reduce volume, with the result of higher OG, to get your desired volume and use less grain next time.

 

[jason91notch]

cool, I think Ive got it then. And Forrest-hunters, great job with that spreadsheet! Very helpful tool. thanks!

 

[el_caro]

Beer Lord...thanks for that link. Does the grain absorption amount come out right even after squeezing the bajeezus out of the bag? Just wondering how much that will affect it.... Thx

First time using the calculator I made the mistake of using the water amounts and squeezing. Result was I overshot my volumes by around 10%. Now I just adjust volumes down, squeeze the life out of it and it is right on the mark. Love it.