First BIAB- Two Brewpots?

[msu09]

Hello All,

Long time lurker, first time poster here. Sorry if this has been asked elsewhere, I've tried looking for it to no avail.

I've been extract brewing for a while now but now feel like I'm ready to take the plunge using the BIAB method. I was wondering if any of you could help me answer a few questions about my equipment/recipe.

I plan on using paint bags with grains that are milled fairly fine. My problem is that I have a five and eight gallon brewpot and would like to make a Hopslam clone (https://www.homebrewtalk.com/f69/hopslam-clone-219599/). Would it be possible for me to divide up the grains into both pots (4 + 4) and produce a five gallon batch? If so, could I just divide the recipe in half?

I appreciate any help that I can get!

 

[TopherM]

The easiest way is to mash the whole thing in the 8 gallon pot, then just use the other pot to dunk sparge.

Let's say you mash using the typical 1.25 qts per lb of grain, that's only about 4 gallons of water that's REQUIRED for a 10lb mash, which will easily fit in your 8 gallon pot. Now, with BIAB, we would typically do full volume, but since you don't have that option, we'll just do a suitable number above the required 4 gallons. So, just to be safe, throw about 5 gallons of strike water in your 8 gallon pot and mash all of your grain in that.

THEN, your total water volume is going to be somewhere around 6.8-7.2 gallons, depending on your grain bill/boiloff rate of your equipment, etc.. So let's say it's 7 gallons. You have 5 in the mash already. When your mash is winding down, you heat the 2 more gallons of water in your second pot to 170F to do a dunk sparge as your mashout. After the mash is complete, you pull the bag, let it drip and drain and squeeze back into the 8 gallon pot, THEN dunk it like a tea bag in the 170F water in the other pot for about 10 minutes.

You then pour the wort from the 2 gallons into the 8 gallon pot, let the bag drain/drip/squeeze into the 8 gallon pot again, and now you have your full 7 gallon volume in the 8 gallon pot for your boil.

This ends up being the same net as doing a normal full volume BIAB. Remember to tweak the #s based on your grain bill and boil off rate!!

Let me know if you have any questions!!!

HMMMMM....1,000th Post...nice!

 

[msu09]

Sounds easy!

I'm excited to switch to try this and see how it works. Trial and error! Maybe one day I'll make a proper mash tun...

 

[cricky101]

The easiest way is to mash the whole thing in the 8 gallon pot, then just use the other pot to dunk sparge.

Let's say you mash using the typical 1.25 qts per lb of grain, that's only about 4 gallons of water that's REQUIRED for a 10lb mash, which will easily fit in your 8 gallon pot. Now, with BIAB, we would typically do full volume, but since you don't have that option, we'll just do a suitable number above the required 4 gallons. So, just to be safe, throw about 5 gallons of strike water in your 8 gallon pot and mash all of your grain in that.

THEN, your total water volume is going to be somewhere around 6.8-7.2 gallons, depending on your grain bill/boiloff rate of your equipment, etc.. So let's say it's 7 gallons. You have 5 in the mash already. When your mash is winding down, you heat the 2 more gallons of water in your second pot to 170F to do a dunk sparge as your mashout. After the mash is complete, you pull the bag, let it drip and drain and squeeze back into the 8 gallon pot, THEN dunk it like a tea bag in the 170F water in the other pot for about 10 minutes.

You then pour the wort from the 2 gallons into the 8 gallon pot, let the bag drain/drip/squeeze into the 8 gallon pot again, and now you have your full 7 gallon volume in the 8 gallon pot for your boil.

This ends up being the same net as doing a normal full volume BIAB. Remember to tweak the #s based on your grain bill and boil off rate!!

Let me know if you have any questions!!!

HMMMMM....1,000th Post...nice!

That's the same way I've been doing it for the last 5 batches or so and it's worked great!

 

[msu09]

I'm guessing that the grain bill for this recipe (almost 20 lbs) would be too big for this method then. Am I right in assuming that? That's why I was wondering if I could split up the grain into two different pots...

I appreciate all of the help!

 

[amingo]

I've done about 10 BIAB recipes in an 8 gal and a 5 gal pot. I typically mash up to 12 lbs of grain in my 5 gal pot (right up to the top), dunk sparge in 3.5 gal of water in the 8 gal pot and then add the wort from the 5 to the 8, resulting in a 6.5 - 7 gal total boil (to allow for boil off and system loss due to sediment throughout the process).

Anyway, seeing as this recipe calls for more than 12 lbs of grain, a simple solution would be to adjust the recipe to 12 lbs of grain by replacing a little of the base grain with extra light DME. It's not technically all grain but nobody will know the difference and it will simplify your process a little.

Happy brewing and welcome to BIAB! It's a lot of fun and feels a lot more like brewing.

 

[wilserbrewer]

Ok with 20 lbs of grain you will have to mash BIAB style in both pots. Ballparking your total water will be 5 plus 1/2trub plus 1.5 boiloff plus 2 grain absorption, totals 9 gallons...or you this BIAB calculator...which also says 9 gal...damn i'm good

http://beerreviewdude.com/biab-calculator/

and this will confirm the total mash will fit in 13 gal...

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

 

[TopherM]

That's 20 lbs of grain for a 5 gallon batch? BIAB starts to have efficiency problems above a OG of about 1.07, so I think you might be a little ambitious here if this is a 5 gallon batch. It can be done, but just note that you may need to actually use even more grain than expected to overcome these inherent efficiency issues for big brews.

In this case, you are probably better off with your original plan of brewing in two separate pots. The method I outlined isn't going to work for that much grain in an 8 gallon pot, as you are going to need 8-9 gallons of total strike water, not even factering in the grain displacement, and a good bit of those 8-9 gallon is going to be lost to absorbsion that you just can't get out. Also, probably a good idea to plan on a 90 minute boil instead of a 60, just to get that OG up to where you need it. It's going to be tight!!

 

[tre9er]

You can always boil down too if need be. Sure it'll affect your hops efficiency some, but better than a small beer, no?

 

[msu09]

I was thinking of splitting the grains into both kettles. Two thirds would go in the eight gallon and one third would go into the five gallon. I'd then combine the two pots of wort together and do a 60 minute boil. Does anyone with more experience than me see a problem with this? I've come to realize that I may be a bit ambitious with this recipe and my limited equipment...

 

[djfriesen]

If you mash really thick, and don't use too much sparge water (assuming you want to sparge to get the efficieny numbers up some), you should be OK.

But I would advise slowly adding any sparge runnings to your boil during the first 15 minutes or so. Your risk of boilover is high if you try to put 5 gallons + any sparge volume into that 8-gallon pot for a preboil volume.

It all comes down to imagination, and pushing the limits. I'm sure you can do it. How much it resembles Hopslam remains to be seen. Good luck!

 

[wilserbrewer]

I was thinking of splitting the grains into both kettles. Two thirds would go in the eight gallon and one third would go into the five gallon. I'd then combine the two pots of wort together and do a 60 minute boil. Does anyone with more experience than me see a problem with this? I've come to realize that I may be a bit ambitious with this recipe and my limited equipment...

I think you're fine...I would do closer to a 60/40 split of grain based on the pot sizes being closer to 60/40 ratio. Max out both kettles...then extend the boil ...always easy to boil more...You could boil in both pots as well to increase boil off and increase efficiency...fear not, it can be done! You actually have plenty of room when considering both kettles of 13 gal total

 

[tennesseean_87]

How big are your paint bags? If you calculate how much grain will fit in your 8 gallon pot at 1.25 qt/lb but then cram all the grain into a 5 gallon paint strainer, you might run into problems.

 

[msu09]

I think i'll try the 60/40 split... 8 lbs of grain in the 5 gallon and 12 lbs in the 8 gallon. I have five gallon paint bags and from all that I've read those two weights should work with the bags. if I use 1.25 qt/lb and then combine the two kettles of wart into the 8 gallon I should be ok. I appreciate all of the help so far and I'm beginning to learn that it's all about the trial and error.

 

[wilserbrewer]

I think i'll try the 60/40 split... 8 lbs of grain in the 5 gallon and 12 lbs in the 8 gallon. I have five gallon paint bags and from all that I've read those two weights should work with the bags. if I use 1.25 qt/lb and then combine the two kettles of wart into the 8 gallon I should be ok. I appreciate all of the help so far and I'm beginning to learn that it's all about the trial and error.

NO No No! 20 lbs of grain at 1.25 qts/lb is only 25 qts or around 6 gallons...you need to start w/ at least 9 gallons of water! That 20 lbs of grain is gonna suck up a lot of water!!! You have 20 lbs of grain...more water! Too much wort can always be boiled down...too little wort is a problem.

 

[msu09]

NO No No! 20 lbs of grain at 1.25 qts/lb is only 25 qts or around 6 gallons...you need to start w/ at least 9 gallons of water! That 20 lbs of grain is gonna suck up a lot of water!!! You have 20 lbs of grain...more water! Too much wort can always be boiled down...too little wort is a problem.

Thanks! What about 40 qts of total water? 24 in the 8 gallon and 16 in the 5 gallon? That would be ten total gallons of water.

 

[tennesseean_87]

At that mash thickness you will need to sparge to rinse out sugars or your efficiency will not be good. Also note that if you put a 5 gallon bag accross the top of an 8 gallon pot and pout 15 qts into the pot, 3 gallons will be below the bag and only 2 qts actually mixing with the grain, so think through how the bag will be suspended and how you'll heat sparge water.

 

[wilserbrewer]

Thanks! What about 40 qts of total water? 24 in the 8 gallon and 16 in the 5 gallon? That would be ten total gallons of water.

Well...10 gallons total water will give you around 8 gallons wort which is too much for a single pot boil...9 will yield 7, so it will barely fit in your 8...more water will help efficiency but will require both pots to boil...up to you.

Now here is something else to think about...with all that grain and such a high OG...you may have a second small batch left in your spent grain. It's called partigyle. Dunk sparge the spent grain bags and you could likely get a 3-4 gallon batch of low to mid gravity brew...or just toss it out if you can't be bothered.

Also best to use a fine crush...or send it through the mill twice if in doubt.

 

[smokewater]

I doubt 20 lbs of grain will fit in a 5 gallon paint strainer bag. You could do it in the 8 gallon pot fine but need a bigger bag. Calculate the strike water volume to fill the 8 gallon pot as full as possible. Batch sparge in the 5 gallon pot to reach boil volume.

I do this all the time with a 7.5 gallon turkey fryer pot and a 5 gallon bucket. For around 12 lb grain bills I start with about 6 gallons of water and sparge with 2. For a 20 lb grain bill you would start with less water and sparge with more.

 

[msu09]

Thank you all for the support!

I've purchased all of my supplies and I think that I am going to go with the following setup. Would it be possible for anyone to tell me if it looks way off? I'll be using two 5 gallon double bagged painted strainers in each pot.

I will be using the 60/40 split that was recommended before. The total batch size will be 5.5 gallons. Using http://beerreviewdude.com/biab-calculator/ I found the following... 10 gallons seemed like a lot, but that's what it said.

8 Gallon Pot- 12 lbs of grain and 5.8 gallons of strike water
5 Gallon Pot- 8 lbs of grain and 4.2 gallons of strike water (will this even fit?)

Thanks!

 

[tre9er]

8 Gallon Pot- 12 lbs of grain and 5.8 gallons of strike water
5 Gallon Pot- 8 lbs of grain and 4.2 gallons of strike water (will this even fit?)

Thanks!

no way that 5-gal pot will hold that.

You only need 3.75g. of strike water for 12lbs. and 2.5g. for the 8lbs. Of course you're trying to avoid using another pot I see.

I'd reduce the strike water amounts, mostly in the 5g. pot, to whatever fits comfortably. Then add the difference to the boil.

 

[edroberts]

The easiest way is to mash the whole thing in the 8 gallon pot, then just use the other pot to dunk sparge.

Let's say you mash using the typical 1.25 qts per lb of grain, that's only about 4 gallons of water that's REQUIRED for a 10lb mash, which will easily fit in your 8 gallon pot. Now, with BIAB, we would typically do full volume, but since you don't have that option, we'll just do a suitable number above the required 4 gallons. So, just to be safe, throw about 5 gallons of strike water in your 8 gallon pot and mash all of your grain in that.

THEN, your total water volume is going to be somewhere around 6.8-7.2 gallons, depending on your grain bill/boiloff rate of your equipment, etc.. So let's say it's 7 gallons. You have 5 in the mash already. When your mash is winding down, you heat the 2 more gallons of water in your second pot to 170F to do a dunk sparge as your mashout. After the mash is complete, you pull the bag, let it drip and drain and squeeze back into the 8 gallon pot, THEN dunk it like a tea bag in the 170F water in the other pot for about 10 minutes.

You then pour the wort from the 2 gallons into the 8 gallon pot, let the bag drain/drip/squeeze into the 8 gallon pot again, and now you have your full 7 gallon volume in the 8 gallon pot for your boil.

This ends up being the same net as doing a normal full volume BIAB. Remember to tweak the #s based on your grain bill and boil off rate!!

Let me know if you have any questions!!!

HMMMMM....1,000th Post...nice!

I've run into a similar situation with my first BIAB. I have 7.5 and 6.5 gallon pots. Unfortunately, the 7.5 gallons was just too small to go without boilovers.

Fortunately my recipe called for a 90 minute boil with the first hop addition at 60 minutes. So, I simply took a couple gallons off my primary pot and did a parallel boil on the kitchen stove for the first 30 minutes. Outside of compensating for the increased boil-off rate, it worked very well. The 30 minutes was just enough time to knock down the total volume and cut enough hot break before I re-combined the two kettles. For a typical 60 minute boil, I'd probably need to cut down the dunk sparge to a gallon and a half or simply up the boil time, still doing the parallel boil.

 

[Komodo]

This may help you. Scroll down to "can i mash it" calculator.

Looks like 13 and 7 pounds might be a little safer. Once you pull and drain the bags, you'll have the volume down away from the rim of the vessel.