How much grain can I fit in a Stout 3bbl MLT?

[YoLong Thomas Chen]

Approx 150KG untreated grain

[YoLong Thomas Chen]

Approx 150KG untreated grain

[ShawnB]

About 330 lbs or 6 55 lb bags. I did a Wee Heavy with 19 brix at beginning of boil.

[C_floyd]

Trying to get the most out of my Stout 3bbl system. Pushing the limits on the kettle has been easy, you can safely boil 135-140 gallons in there if you keep your hose and anti-foam at the ready. What I really want to know is how much grain can I put in the MLT. I've brewed some 17-18 plato DIPAs, around 250-260lbs of grain with an 86-88% Mash efficiency (according to my beer smith calculations). What I am eyeballing is a 20+ plato Imperial Stout to go in barrels. Can I get 350lbs of grain and 120ish gallons of mash water in there without overflowing? My alternative is to boost the gravity with Belgian Candi and regular sugar but I want to hear it from other brewers who have pushed the limits on these little things.

Cheers!