What kettle size is recommended in BIAB brewing?

[Elysium82]

According to a website the ideal size is 50% extra of your final batch size, but minimum 30%. That is of website that doesn't refer to BIAB (I guess it is just the preboil size).

So, if I'd like a final batch size of 1.5 gallons...then my mashing size is 3.5 gallons (with a simple low grain bill of an APA recipe). Then if I am right, I'd need a kettle that can hold a minimum of 4 gallons, right? That would account for the grain bill, the mashing water, and would leave some space. Am I missing anything though? Or is there a simple rule of thumb one could share?

Thank you.

 

[grampamark]

The general rule of thumb, for BIAB or 3 vessel, is to use a kettle that’s twice your batch size. If you plan on brewing higher gravity beers, or want to brew a larger batch occasionally, 150% is better.

Really, when you stop to think about it, the cost of the next size larger kettle than you really need is relatively small, when considering the flexibility provided by the larger size.

 

[enkamania]

The general rule of thumb, for BIAB or 3 vessel, is to use a kettle that’s twice your batch size. If you plan on brewing higher gravity beers, or want to brew a larger batch occasionally, 150% is better.

Really, when you stop to think about it, the cost of the next size larger kettle than you really need is relatively small, when considering the flexibility provided by the larger size.

I started with 10 and then moved to 15 gallon.

 

[ChiknNutz]

If you plan to perform a full volume BIAB, meaning no sparge, then ROT is to have your kettle 3X your finished batch size. As such, I recently moved from a 10G kettle to a 15G and find it to be the proper size with enough extra to not be worried about boil over. This is for 5G finished batches. This also allows for "bigger" beers.

 

[hotbeer]

I don't see where BIAB is going to make any difference. Unless the way you go about doing it requires bigger. There are too many methods to mash and sparge whether BIAB or not.

So it's hard to really say until it's known exactly what you intend to do step by step. But I did BIAB for my first brew in pretty much the size stuff they recommended for the grain kit that wasn't aimed at BIAB and it worked out well and tasted as good as many of the beers I've bought.

What ever size you get, make sure you have the heat to bring the size of your batch to a boil as well as the size kettle to contain it.

 

[odie]

3x rule. 3 times your planned batch size is what you want. That will cover anything you want to make.

https://www.homebrewtalk.com/threads/what’s-the-best-biab-kettle-size-for-me.688264/

 

[Elysium82]

I don't see where BIAB is going to make any difference. Unless the way you go about doing it requires bigger. There are too many methods to mash and sparge whether BIAB or not.

So it's hard to really say until it's known exactly what you intend to do step by step. But I did BIAB for my first brew in pretty much the size stuff they recommended for the grain kit that wasn't aimed at BIAB and it worked out well and tasted as good as many of the beers I've bought.

What ever size you get, make sure you have the heat to bring the size of your batch to a boil as well as the size kettle to contain it.

I plan to mash, then boil in the same kettle. I know it is not ideal since a kettle loses temperature quicker than a cooler, but for the sake of simplicity.....I think a all-in-one kettle is the way for me to go about this.
I might add a cooler in the near future, but I am still at the planning stage. I am waiting for this covid madness to be over and move somewhere permanently.

 

[hotbeer]

I plan to mash, then boil in the same kettle. I know it is not ideal since a kettle loses temperature quicker than a cooler, but for the sake of simplicity.....

I don't see that as an issue. Did you say this was your first brew? Don't expect everything to go well, don't expect the beer to win awards. Then you'll be surprised when after carefully thinking everything through that it did go well and the beer does actually taste decent.

I can turn my stove burner down to a very low simmer, and I also have a large griddle plate I lay over the burner to further help me modulate the temp after the waters come to temp.

But if you can't control your temps as well like that, then just wrap something around the kettle. Burner off of course. I've heard of people using blankets, old sleeping bags... whatever insulates. You'll probably be surprised how long it holds temp.

But if you keep taking the lid off to look and stir, you'll have to have a way to replace that heat. So make certain it's easy to remove and put back on.

Doing it all in the boil kettle isn't a problem. I'm thinking I might do my primary ferment in the kettle next time and rack to a secondary afterward.

I only have two batches under my belt and one still in the fermenter. So I might be telling you bonehead stuff and just not know it.

To a certain extent I have to learn from my own mistakes even when others tell me I'm wrong.

 

[Bobby_M]

10 gallon for moderate gravity 5g batches
15 gallon for any gravity 5g batches
20 for 5/10.

 

[Elysium82]

But if you keep taking the lid off to look and stir, you'll have to have a way to replace that heat. So make certain it's easy to remove and put back on.

Well, I have brewed before, but that was a million years ago. Plus I am thinking of a different set-up now...so, that changes things too. So, it is safe to say that I am a newbie. Btw, is stirring necessary at all? Does it provide higher efficiency or anything?

Doing it all in the boil kettle isn't a problem. I'm thinking I might do my primary ferment in the kettle next time and rack to a secondary afterward.

How can you do that though? how can you seal it as well as a fermenter would do? Where would you put the airlock? It is a great idea, but I just dont see how it could be done.

 

[hotbeer]

hotbeer said:
Doing it all in the boil kettle isn't a problem. I'm thinking I might do my primary ferment in the kettle next time and rack to a secondary afterward.

How can you do that though? how can you seal it as well as a fermenter would do? Where would you put the airlock? It is a great idea, but I just dont see how it could be done.

I don't know that it needs to be sealed well for the primary ferment. That's only going to be two or three days for it to settle back down at the most.... I think. Hopefully it'll be making so much gas just 12 hours after pitching, that it'd be silly to seal it tight.

Just a nice fitting lid should do and it can leak as much as it wants. Maybe crumple a long strip of aluminum foil around the rim of the lid and pot to help keep the lid where it should be. Remember, it's just for a few days while gassing off a lot.

I read of some fermenting in a kettle doing this. Not sure if it was the entire contents of their boil. But why not if it appears to be reduced to the correct volume and is about the right SG?

When the more violent part of the fermentation is done you can put it in secondary fermenter. Sanitized and clean of course. Maybe blow a little CO2 in it to displace some of the air first. The CO2 inflator I keep on my bike for flats on the road ought to be able to supply that.

 

[renstyle]

...I might add a cooler in the near future, but I am still at the planning stage. I am waiting for this covid madness to be over and move somewhere permanently.

I went this route, got a cooler to do MIAB. The hardware needs (for building a mash tun) are GREATLY reduced if you just use a bag with a cooler. I swapped out the bulkhead with a SS ball valve, and that was about it!

Using a cooler would allow you to work with a smaller kettle. For 5 gal batches I'd still recommend 8gal minimum, 10gal optimum, which is still in the 1.5x-2x sizing that others have mentioned.

The 3x AIO-no sparge setup sizing is also a good rule of thumb. For smaller 5gal batches you'll have alot of room in the kettle once the grain is removed, which may or may not be a plus.

Dollar-wise, it's prolly a wash between a 15gal kettle mashing/BIAB kit and a 8/10gal kettle with a cooler, even if you account for the extra Reflect-X you pick up to help insulate the 15gal.

 

[Leezer]

FWIW, I do 2.5G biab in a 4G kettle, mash and boil in same kettle. I put a heavy blanket and a couple beach towels over the kettle during the mash and just leave it alone, only lose a few degrees. I use a slightly smaller kettle for 1.25G batches.

 

[CascadesBrewer]

So, if I'd like a final batch size of 1.5 gallons...then my mashing size is 3.5 gallons (with a simple low grain bill of an APA recipe). Then if I am right, I'd need a kettle that can hold a minimum of 4 gallons, right? That would account for the grain bill, the mashing water, and would leave some space. Am I missing anything though? Or is there a simple rule of thumb one could share?

I am not quite sure what size batch you want to make. Using full volume mash BIAB I am pretty happy using a 5 gal kettle to make 2.6 gal batches and a 10 gal kettle to make 5.5 gal batches (that is volume into the fermenter). Both those setups can handle a beer up to around 1.070. For a bigger beer I just need to hold back some of my mash water for a dunk sparge in a bucket or another pot or just brew a smaller batch. I could also reduce the volume into the fermenter or reduce my 1 gal of boil off with a shorter boil or less vigorous boil.

If you want to make 1.5 gal batches, I see such little difference in price between 3 gal and 4 gal kettles, that I would get a 4 gal one...but you could likely be fine with a 3 gal kettle.

If you are starting from scratch, I would make sure to look at the electric all-in-one systems.

 

[Saunassa]

I do 5 gal batches with an 8 gallon kettle. I cannot do full volume mash I have to keep a gallon out so I have room to stir. I originally purchased the 8 gal for stove top brewing but now that I use a garage burner I wish it was a 10 gal kettle.
My wife has an 11 gal bayou classic with a basket but it does not have a valve and not sure I want to add one since it is her jelly making kettle.

 

[Toxxyc]

I brew 42l batches in a 50l electric urn. I mash in the urn at 1/2 volume, and then I do a double dunk sparge in two separate vessels each containing 1/4 of the kettle volume. All the wort is then poured into the urn for the boil.

So, for example, I'll mash in 25l of water in the 50l urn. I then dunk sparge in two buckets, each containing 12.5l of water. Everything is poured into the urn and the end result is around 45l of wort in the urn, which is boiled down to my batch size during the boil.

 

[jtgoral]

I use 66 quarts for 5-6 gallon batches.

 

[balrog]

if I'd like a final batch size of 1.5 gallons...then my mashing size is 3.5 gallons (with a simple low grain bill of an APA recipe).

What @Leezer says. If full vol mash + grist is 3.5 you want 4G kettle for some margin of error. Spilled wort is super sticky messy.

 

[odie]

I plan to mash, then boil in the same kettle. I know it is not ideal since a kettle loses temperature quicker than a cooler, but for the sake of simplicity.....I think a all-in-one kettle is the way for me to go about this.
I might add a cooler in the near future, but I am still at the planning stage. I am waiting for this covid madness to be over and move somewhere permanently.

skip the cooler. just put a wrap around the kettle. reflectix works great or even some towels, blankets, sleeping bag, etc. Just watch the burner if you are not electric.

 

[odie]

I don't know that it needs to be sealed well for the primary ferment. That's only going to be two or three days for it to settle back down at the most.... I think. Hopefully it'll be making so much gas just 12 hours after pitching, that it'd be silly to seal it tight.

Just a nice fitting lid should do and it can leak as much as it wants. Maybe crumple a long strip of aluminum foil around the rim of the lid and pot to help keep the lid where it should be. Remember, it's just for a few days while gassing off a lot.

I read of some fermenting in a kettle doing this. Not sure if it was the entire contents of their boil. But why not if it appears to be reduced to the correct volume and is about the right SG?

When the more violent part of the fermentation is done you can put it in secondary fermenter. Sanitized and clean of course. Maybe blow a little CO2 in it to displace some of the air first. The CO2 inflator I keep on my bike for flats on the road ought to be able to supply that.

certainly an interesting idea. nothing wrong wit it. back in the day fermenters just had a loose lid on them. I know breweries that still do just that and make great beer. Your kettle should have a nice fitted lid so no problems. I think the timing needs to be good so that you can rack to a secondary while there is still enough activity to then purge the secondary of oxygen from the transfer. I would say immediately after krausen falls.

 

[Oldskewl]

I would definitely go 2 1/2 to 3 times the size of the batch you intend to brew. I went a 15 gallon kettle for my 5 gallon batches and 6 a gallon kettle for my 2 1/2 gallon batches. Never had any boil overs or run overs. No regrets. Only downside is it is a larger kettle to store and clean. But I store brewing supplies in mine.