5 gallon BIAB solutions for a 7 gallon kettle

SabreSteve

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So I brewed today so naturally I'm already thinking about my next batch. I've gotten the hang of extract batches and I'm looking to move more towards BIAB, mainly to lower my ingredient costs. Figure if my batches cost half as much then I could brew twice as often without feeling bad. The main problem is doing 5 gallon batches I only have a 7 gallon kettle and I'm not in a place financially to buy a larger one right away. I'm just wondering what options might be best with what I have. Do I just do a smaller boil, add a smaller amount of DME to really pump up the gravity and then top off with water like an extract batch? Managed a 5 gallon boil today and it was close, had only about an inch to spare during hot break, ended up with roughly 4.5 gallons in the fermenter before topping up. Do I press my luck and attempt a 5.5 gallon boil and pray for no boil over? I've seen some on here talk about doing two boils and combining them but I don't think that's really an option for me if I'd have to do one after the other. Today was crazy, managed to cram most of my brewing in during my son's nap and between that, wrangling him and trying to clean up while wrangling him I'm wiped. So yeah if I could get some advice on the best way to proceed then I can hit you guys up for more advice in the recipe forum:D

If I can find a reliable and effective way to make my batches with my current equipment I may just put off upgrading my kettle long term until I can get one of those electric all-in-ones.
 
I have been in those shoes and it sucks. I was using a 8 gallon pot for the first year but it was really making me hate the process so I took the plunge and bought a 15 gallon stainless beauty and never looked back! Maybe if you keep 2 spoons on the rim, you'll keep the boil overs down! ;).

Having only done extract once, that "fill the rest of it with water" method seems to be a common approach from what I understand. It makes sense in theory but I can't talk to practice...I mean you are brewing a concentrate so I can't imagine what that does to your gravity numbers and any other numbers BEFORE you add the water. Where it may pay off is in cooling the wort. I think you may be wanting to look at small batches given your hardware and brew more often. Look at it this way, you'll get to work on your repeatability!
 
Typically for a comfortable BIAB process for a 5 gallon batch, you need a 10 gallon kettle, but it could be done.
Having said that, it would be advisable to keep it simple for your first mash, and not take on such a challenge on your first BIAB batch, your first mash for that matter.
Shoot for a 4 gallon batch, keep it simple. Watch videos of guys doing BIAB too.
Let me know what you think. My memories of my first BIAB batch are fresh in my mind, I would love to help you through it!
 
If what you want is 5 gallon batches but a 7 gallon kettle is what you must use then topping up seems like the only option. Figure out what the post boil gravity of a 5 gallon batch would be. Then use the dilution/boil-off calculator and reduce the volume to 4 gallons. That will give you the post boil target for a 4 gallon batch. Then top off with a gallon of water when going into the fermenter and that should get you back to the 5 gallon target gravity.
 

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That makes total sense!
I would have never thought of that!
So you want to plan on a 4 gallon batch with a 1.075 OG, then add a gallon of water which brings your OG down to 1.060.
 
@BarbarianBrewer has the answer. I've done a version of that many times and it's actually pretty easy to do. You just make 25% less beer that's 25% stronger than you want and top up.
If you get your equipment profile settings right for the batch size, the IBUs will come out right. The calculator doesn't care how you get to the numbers, It just knows that the pre-boil gravity will be X and the fermenter gravity will be Y and it knows how to make the hop uptake right.
 
I would just go for smaller batches. 5 gallon is not a must!
Once you get the hang of it and want to do bigger batches, then use the top-up method.
See if you enjoy biab before buying a bigger kettle. Maybe you decide you want an all in one system or herms or maybe you prefer to stick with extract ;)
 
I would just go for smaller batches. 5 gallon is not a must!
Once you get the hang of it and want to do bigger batches, then use the top-up method.
See if you enjoy biab before buying a bigger kettle. Maybe you decide you want an all in one system or herms or maybe you prefer to stick with extract ;)
You're probably right but I'm stubborn so I'm probably going to try shooting for a more concentrated 4 gallon wort then topping off with water. I know it's not a big deal but the unused space in the fermenter would bug me :D

If it doesn't work you'll owe me an I-told-you-so and I'll do smaller batches next time
 
Ok, hoping I did this right. Built a BIAB recipe with a target of 5 gallons to get my numbers where I wanted. Then consulted the boil off/dilution calculator to see what my OG should be for the concentrated 4 gallon wort. Then changed the target volume to 4 gallons Consulted a BIAB calculator for my water needs and to make sure I could accommodate the total mash volume without having to scale back on the grains and add DME to pump up the SG. Set my mash guidelines and then made a snapshot where I put the target volume back to 5 gallons so I have a reference to what my final numbers should be. Other than the fact that I could have made the 4 gallon version the snapshot and saved a step did I miss anything or does anyone have a better way?
 
Ok, hoping I did this right. Built a BIAB recipe with a target of 5 gallons to get my numbers where I wanted. Then consulted the boil off/dilution calculator to see what my OG should be for the concentrated 4 gallon wort. Then changed the target volume to 4 gallons Consulted a BIAB calculator for my water needs and to make sure I could accommodate the total mash volume without having to scale back on the grains and add DME to pump up the SG. Set my mash guidelines and then made a snapshot where I put the target volume back to 5 gallons so I have a reference to what my final numbers should be. Other than the fact that I could have made the 4 gallon version the snapshot and saved a step did I miss anything or does anyone have a better way?

Looks like you've got it!
 
Hello SabreSteve,

I've got a similar situation and wanted to know how that technique worked out for you.

I have a 14l kettle and making 8l batches with BIAB. Fed up with the auto siphon, I just got an SS Brewtech mini (3.5g) and would like to fill it up more than 2g of course. Do I need a bigger kettle or do you think I can shoot for, say 2.5g with this technique?
 
Ihave 7 gallon pot and do 5 gallon batches all the time. Preboil 1-2 gallons and put it in your fermentor. (Or sanitised container) When you end up with 4 gallons of wort then you have the dilute already in place.
 
In the Third Book of Exodus when the people were fleeing sorghum beer in search of barley, the Lord most high said, "Four gallon batches are just fine."
Yes but you're forgetting the 14th commandment that states : thou shalt goeth big or thou shalt goeth home"
 
well, 2.5 gallons for my setup is going big :)

using Brewfather, there is a setting for "top-up" and it looks like that's exactly what i need here. i changed my recipe to target 2.5g, instead of 2g, and it automatically scaled ingredients to that volume. then i adjusted "top-up" accordingly. only the bittering hops were automatically scaled up a bit after that change. i think this is totally cheating, but i'd love it if it works!

i have no experience with extract brewing, but isn't the idea similar in that you work with concentrated wort and top-up in the fermenter?

does it matter if the top-up water is boiled or not? Brewfather suggests that it be cold and actually that would help cooling of course.

also, i am not making water adjustments, but i suppose that could be affected as well.
 
You probably just don't want chlorinated water.
 
I used water straight out of the tap for my first 7 or so batches without incident. Might need campden if you have chlorinated water but otherwise I wouldn't stress.
 

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