getting ready for 1st biab, but i have questions

nygel74 · Jul 9, 2015

First off, I am super excited to be trying my first BIAB recipe, but after buying my ingredient, I do have some questions.

1) I have a 7.25 gallon pot, am using 10.25 lbs grains and plan on doing a 5.5 gallon batch, is it doable?
2) If it is doable, should I go to the gusto, max out the pot and do a no sparge for my first go round?
3) Should I tone down the primary brew pot and then sparge, with dunk sparging? If so, how long do I dunk sparge for? does the ration between the primary and the sparge pot, water wise, need to be 50/50 or can I do what is comfortable in the primary pot and then use the dunk pot to make up the rest?

I have been reading the forum for some time now, just trying to get my feet under me as I am new to this hobby, so I really appreciate the info and the time! Thanks in advance!

brew703 · Jul 9, 2015

I'm not the person to be replying to this thread, but if you are doing a 5.5 gallon batch, you will probably need about 8 gallons of water so that would already exceed your pot capacity not to mention once your grain is added it will increase the volume. From what I have read, you may need to use a cooler or get a bigger pot.

soccerdad · Jul 9, 2015

As brew703 said, you are beyond maxed out at 10+ pounds. Get as much water as you can in the kettle/tun and do what is comfortable in the dunk pot. No need to go 50/50 but if that's what makes you comfortable .....

verysupple · Jul 9, 2015

brew703 said:
I'm not the person to be replying to this thread, but if you are doing a 5.5 gallon batch, you will probably need about 8 gallons of water so that would already exceed your pot capacity not to mention once your grain is added it will increase the volume. From what I have read, you may need to use a cooler or get a bigger pot.

I'm glad you started with the bit in bold. A cooler for BIAB? Hmmm.

Anyway, no, that pot isn't big enough to do a full volume mash for a 5.5 gal batch.

You could mash with 4 gal and then do a dunk sparge in another 4 gal which should give you ~6.5 gal pre-boil if you don't squeeze the bag. If you do squeeze the bag you might want to sparge using a couple of quarts less. If you boil off ~1 gal/h (which is about right) you'll end up with your 5.5 gal post-boil volume after a 1 h boil.

As for doing the dunk sparge, it's nice and easy. Heat up your sparge water in another pot to ~175 F. Carefully lower the grain bag in and give it a mighty good stir to make sure everything is well mixed. You can let it sit for 5 or 10 min, but I've never noticed a benefit in waiting, I just lift and drain the bag again once it's properly mixed.

Now, I see two kind of big problems. 1) You need a second big pot of at least 5 gal capacity. 2) You need to boil ~6.5 gal in a 7.25 gal kettle. That's a bit of a tight fit and you're going to have to be super careful, especially during the hot break, not get a boil over.

Luckily there's a solution to both of these problems. Brew it over gravity and then dilute it back to your desired OG in the fermentor. In this scenario you would mash with as much water as fits in you kettle (I calculated you should be able to fit 5.75 gal plus your 10.25 lb on grain). This means you only need the one pot you already have and because the boil volume will be quite a bit smaller you will have less problems with boil over, reach a boil faster, and chill faster. Transfer the wort to your FV and measure your volume and gravity. Then it's quite simple to calculate how much extra water you need to add to reach your desired OG. A bonus benefit to this method is that if your boil off or efficiency are different to what you expected you can adjust for it here - you will ALWAYS hit your OG by adjusting your volume. Also, you don't have to mess around with another pot for the dunk sparge and overall the brew day will be simpler and more enjoyable.

Happy brewing.

RM-MN · Jul 10, 2015

nygel74 said:
First off, I am super excited to be trying my first BIAB recipe, but after buying my ingredient, I do have some questions.

1) I have a 7.25 gallon pot, am using 10.25 lbs grains and plan on doing a 5.5 gallon batch, is it doable?
2) If it is doable, should I go to the gusto, max out the pot and do a no sparge for my first go round?
3) Should I tone down the primary brew pot and then sparge, with dunk sparging? If so, how long do I dunk sparge for? does the ration between the primary and the sparge pot, water wise, need to be 50/50 or can I do what is comfortable in the primary pot and then use the dunk pot to make up the rest?

I have been reading the forum for some time now, just trying to get my feet under me as I am new to this hobby, so I really appreciate the info and the time! Thanks in advance!

1. Yes it is doable but with limitations.
2. No, you cannot go to full volume, you will need to add a sparge with that size of pot.
3. Dunk sparge or pour over sparge both work, no particular ratio to the strike water to sparge.
4. You will be near the maximum wort for that pot so you will have problems with boilover when you get the hot break. One solution is to keep back your sparge until you get hot break with the initial amount, then add the sparge wort. You will then get a second hot break when the wort comes to a boil again but it will be smaller and less likely to boil over. You can also start with a smaller volume of more concentrated wort and add water as some of it boils off so you end up with your desired 5.5 gallons.

nygel74 · Jul 10, 2015

thanks for the advice everyone, these are exactly the answers I was looking for. After I read the suggestions from Verysupple, I was floored. I have been pondering this little situation for the past couple of days and was focused on the volume of the batch mainly. The idea of using what I have and then diluting it to a OG in my range really opened my eyes. If you don't mind me asking, what exactly is the math to find out the amount of water I need to add at the end of the boil to get my desired OG? Thanks again everyone, the brew day is scheduled for this evening and I really cant be more excited!

indymedic · Jul 10, 2015

I don't have the link but you can search for priceless BIAB calculator. It on the forum. I use it for all my brews and it's been very acurate and valuable to me. Hope this helps

pricelessbrewing · Jul 10, 2015

Thanks for the shout out. Gravity is a linear process so 4 gallons at 1.060 would be 1.048 at 5 gallons. (60*4 / 5 =48) or to get a specific og (4*60 / 50 =4.8)

nygel74 · Jul 10, 2015

Thanks for info. Gotta say, with this advice I am much less nervous about brewing and far more excited! Thanks again, and I will report back with progress.

nygel74 · Jul 11, 2015

alright, with the new found confidence from the advice I was given, the brew day went pretty well last night. I used 5.5 gallons of strike water, heated to about 150 and ended up mashing at 147-148 for one hour. I drained the bag, squeezed, and sparged with one gallon which made my pre boil volume around 6 gallons. the pre boil gravity for the recipe was 1.039 and I had 1.042. next was a 90 minute boil, and since I added some fermcap I had no issues with boil over, or excessive foaming. Once I chilled and put in the FV, checked the gravity and corrected my volume to 5.5 gallons, my OG was 1.051 and the target was 1.049. All in all, I think the brew went pretty darn well for the first time. The recipe was written with 70% efficiency, and given my numbers, I think I was around there. I pitched the yeast a little warmer then I would have liked, simply because the clock was pushing midnight by that time, and today the FV airlock is gurgling away. I am really looking forward to seeing the end product, and thanks everyone for the headsup and the advice, it really helped with the process yesterday!!