Update: I laughed at the $1.25 bread flour test kit at a garage sale in Tulsa, now my sourdough finally works
I picked up a bread flour test kit for a buck twenty five at a garage sale in Tulsa three weeks ago mostly because my wife dared me to. The kit is just a little jar of iodine and a chart, you drop it on a pinch of dough and the color tells you how much starch turned to sugar. My starter had been dying on me for two months, flat loaves, no oven spring, the whole sad show. I tested my usual bulk bin flour and the iodine went almost black, meaning way too much starch and not enough sugar for the yeast to chew on. I switched to a stone ground flour a guy sells at the farmers market on 11th street and the same starter doubled in 5 hours instead of 12. Three bakes later I am getting a real open crumb, which I had honestly given up on. Has anybody else played with the iodine trick or is this just an old baker thing that never made it to YouTube?
My wife still brings up the garage sale flour kit at dinner parties like I discovered fire or something, so you are not alone in the weird science club. The iodine thing has been around forever but nobody talks about it because it is not as fun as blaming your starter for everything. I did the same test last winter and found out my cheap store flour was the problem the whole time, which made me feel real smart after two years of cursing my own hands. Stone ground stuff from a local mill is a whole different ballgame since the grain has more of the good stuff left in it. Old bakers knew what they were doing long before we had ten hour YouTube videos explaining why we failed.