by davis88 » Wed May 24, 2017 2:12 pm
I dont do big batches, but i do multiple smaller batches. I have a 40 L stainless Insulated mash tun i bought off of ebay for about $250. This thing is amazing for mashing corn!!
First i boil 2/3 parts of my mash water to a hard boil, then pour the hot water into my mash tun, then i add my corn (which is stock feed cracked corn from the Feed store) (i also grind the cracked corn through my grist mill 4 times on the finest grind, to get it as fine as i can) i stir the hot water and corn with a power drill for a few mins till its all mixed up, then add a 1/4 tsp of high temp Alpha to pre mash (purely so that the corn is easier to stir and i dont get dough balls anywhere). I cover it up for about 15 mins to gelatinize the starches. then i add the remaining water. which is 1/3 overall mash water, straight from the cold tap of my sink, this brings the overall mash temp to 60-62 deg, stir with power drill, then add crushed malted barley, stir for a few mins. I then go back at stir with the drill a couple more times every half hour, cover it up and leave it for 6 hours. after 6 hours the grain has sunk, i take a sample for iodine test, which is always good (no blue or purple), i transfer to fermenter and cool, take Gravity reading ( i use 2 lb of grain to a gallon of water and always hit 8% potential ABV). once cooled i pitch yeast (US-05), which i usually make a starter from my mash.
The following cpl days i repeat this process ( yielding 100 -120 L Corn mash)
Its doesnt take much time or effort to mash like this, once your comfortable with the process, but i can see wanting to do 100L in one shot tho.
you could scale up my process with great results, but you will require a large insulated mash tun.
i hope that helps some how