We need to remember the yeast balls are made regionally. There are loads of them out there, and we are only getting a small sample. They even come in patty cake shapes, wrapped in colored wax paper, etc. The yeast that is rampant in that area helps contribute to these yeast balls. Or so all the articles I have read tell me. The only one I see being made in a more controlled environment is the Angel Rice Leaven. The yeast balls appear quite primitive, and I recall a photo of the 'curing area' showing bamboo mats on the ground, covered with balls, covered by screens, sitting outside in the sun. So depending upon what yeast you have, you may get sweet, sour, etc. We know now that our water amount when cooking plays a huge roll, as does the rice, the # of days before you harvest and whether you stir the sediment back in or go 'all clear'. Plus many of us are sharing/trading/buying different brands of yeast amongst ourselves to get a better comparison. (I have five different ones now, and need to find time to get things made)
Speaking of...have you had a chance to make anything out of the Angel Rice Leaven you purchased from me? I'm interested in your feedback. How about the yeast balls? I thought they were different too.