I ferment my stuff in a 7 . 5 liter crock that looks like a little like this andkkeramic 7 l i t e r g e r m a n fermentingcrockpotgartopf . htmlYou can only fill it up about 34 full , as you need room for the stones and also headspace for the oxygen replacement . To get it to be 34 full , I need to shred about 5 kg of cabbage and then I pack it in with a giant potato masher , adding salt as I go . That ' s around 11 pounds of cabbage . Eating two pounds of cabbage is completely possible when it ' s kraut , because it will have lost a lot of its internal moisture . He ' ll be eating like 34 pound of kraut , not two pounds of it . And the bet said cabbage . So all he needs to is ferment two pounds of cabbage and eat the result . The one thing he will have to watch out for is the . reaction that will happen when someone not used to a lot of lactofermented foods eats a lot of it . Those little bacteria produce a lot of gas . And other stuff , and they ' ll boot out any lurking unwanted bacteria with something resembling the intestinal equivalent of gale force winds . He ' ll need a good book .