Hmmm. Great question. I didn't learn about oxalates until after I got my first kidney stone that was too big to pass. Nowadays, I know I'm getting too many oxalates if I have urinary symptoms like trouble urinating, frequency, leaking etc. I also get pelvic pain from high oxalate foods. If I'd known these symptoms were from high ox foods, I woulda been looking for these. hth ... x ps. There may be other ways of testing but I've gotten used to watching for my symptoms. I'm eating romain, parsley, cilantro, dandelion, pineapple, apple, seedless grapes, bananas, squash, peas ... Removing the stems reduces oxalates dramatically. Boiling reduces ox too. Just throw away the water. That's how i make dehydrated kale.