Water to grist ratio

[anmldr]

Have been brewing for about 6 months. I have done the 3 vessel system, but my last three batches have been BIAB. I am going to try a IIPA that has 17.5# grain and 1# hops. I have been using at 10.5 gallon aluminum pot with basket. When I do the BIAB calculator it says the ratio comes to 2.0 qt/lb. the other BIAB's I've done have been an IPA and a brown ale with 10-13# of grain. They have been filled to the brim during the mash. With my current set up will I be able to do a full volume mash, should I spagre, or bring out the 10 gallon mash tun.

I have a 15 gallon brewpot coming and will be getting a custom bag once I get it.

I guess my question is with a 10 gallon pot and a 17.5 # grain bill trying to do BIAB what would be your method.

Thanks in advance

 

[wilserbrewer]

With a 10 gallon pot, I would strike at 1.8 qt / lb, or 7.75 gal, resulting in 9.2 gallons mash. Less grain absorption would leave you around 6 gallons preboil, so with a gallon boiloff and a half gallon loss to trub you will only have 4 1/2 gallons.

So therefore you will need about a gallon sparge that can be accomplished by slowly pouring a gallon through the bag held over the kettle, or by dunking / and stirring in another pot or a bucket.

It can be done.

edit, this assumes not using the basket and having a bag large enough to line the whole kettle, and strong enough to lift the grain.

handy link here, Can I mash it...
http://www.rackers.org/calcs.shtml

Another idea is to mash in the 10 gallon pot with 5 gallons, then rinse the bag in the cooler with the other 4 gallons required...combine and boil. Or mash in the cooler with the bag, then sparge in the kettle...