planning an upcoming big beer for a fundraising event. I will be brewing 5 gal of a 1.100 stout. I have a grain bill of around 25 lbs. of grain into a 10 gal igloo cooler mash tun. BS is telling me to add 8.5 gal. water to mash in - there is no way that it will all fit into my igloo, 25 lbs. of grain has to take up more than 1.5 gal. of room. so I figure no prob, I will just adjust my "fill mash tun to 90%" down to 80%. and BS tells me ... to add 8.5 gal of water at mash in? adjust down to fill to 70% and still 8.5 gal of water. so two questions: 1. am I right that this can't possible fit? and 2. is 8.5 gal the minimum water you can add to get a this gravity?