Big beer strategy w/o a huge mash tun

[foomench]

Not sure why you think you need a bigger tun. I can get 25 lbs of grain into my 48 qt cooler, which was enough for a 1.106 Wee Heavy a couple weeks ago. If yours is 70 qt, you should be set.

+1.
I have a 48 qt Igloo Ice Cube with a perforated stainless steel false bottom (picture here). I've managed 26 lbs of grain. For 10 gallons of really big beer I've added a little extract.

[Bugeater]

Here is another thing you might want to think about. Quite often folks end up with too high a final gravity when doing a big beer. Even if you do the thin mash and low mash temperature your gravity may end up high. This is generally due to high osmotic pressure in a high gravity wort breaking down the cell walls of the yeast (a really big yeast cake will help this) leaving the yeast too weak to finish where you want. Even a 75% attenuation of an 1.120 wort is still 1.030 which may be high for some folks tastes and for some big beer styles.

You may want to think about using some sugar for some of your gravity instead of getting it all from malt. This will ferment out pretty much complete and give you a lower FG. Add the sugar (dissolved in some boiled and cooled water) to the wort just as fermentation reaches high krausen and you will get some really nice attenuation. In addition, the late addition of sugar will help avoid some of the osmotic stress on the yeast.

Wayne

[dmtaylor]

Maybe I missed something, but..... is there a reason you're not double sparging and then just boiling for a good 120 minutes? This will increase your efficiency and allow you to make more high gravity beer with the existing tun. Since you are batch sparging, instead of splitting the runnings between first runnings and the sparge, now you split it three ways, 1/3 for the first runnings, 1/3 first sparge, 1/3 second sparge. This will maximize your efficiency, and waste less of those delicious sugars. Otherwise it might make sense to partigyle and use the second sparge for a second smaller beer. But you can collect this all into one and do a big batch of a big beer. It works -- I've done it several times, with great results.