PJ, my sleep schedule is worse than yours (I was headed home when you were measuring!) so I may not have a clear head yet either, but: 1/4 cup of flour is 1 oz, not 2 oz., because in KAF recipes, a cup of flour is about 4 oz. (You know this, but I just want to be clear in showing my work that you mixed 2 oz of flour and 2 oz of water!) I would expect this result to take less than 1/4 cup (4 tbsp) of volume, because some of the flour will "dissolve" in the water and the mixture will not take up the same space as combining two solids of similar density or two liquids. (Adding 1 tbsp salt to a cup of cracker crumbs doesn't make the cup overflow; the salt fills in the gaps between the crumbs.) But I would expect it to weigh four ounces. I don't see how it couldn't, unless it's been sitting out for a long time and there's been enough evaporation to register on a scale. I went back and read the sourdough section in Jeffrey Hamelman's Bread last night, and noticed that he talks about his "cultures" using baker's percentages (of course), and that he keeps one stiff one with 50% hydration and one liquid one at 125% hydration. The percentage is the weight of the water compared to the weight of the flour, so the starter we're talking about has 100% hydration: equal weights of flour and water. The question is, over time, does this change? I'm kind of thinking it might, because the purpose of the starter is to breed tasty yeasties (and their companion bacteria). As the yeast digest the starches in the flours, they give off acetic acid (or lactic acid) if they're not exposed to the air, but they give off carbon dioxide if they are. That, being a gas, makes the starter "bubble," but more importantly, it escapes into the air. Over time, some significant quantity (even if it's a very small significance) of the mass of the flour is converted into CO2. But I think this requires oxygen from the water in the starter to work, so the mass of the water reduces as well. By the same amount? Oy, I dunno. It's been decades since I avoided taking organic chemistry! My gut feeling is to believe that for home quantities of culture/starter/levain, the flour and water are probably consumed at roughly equal amounts, so a specified volume of a 100% hydration starter should weigh the same amount, with minor variances like your 1/4 ounce observations, even after years of feeding and using it. Which still makes me think that if your starter consistently weighs 8 oz per dry measure cup, mine is a lot more liquid than yours, because mine seems thin and thinner starter would weigh less per cup. I'm going to feed it again today and next time I use it, I'll weigh a dry-measure cup of it to see what I get. I also want to be clear that I'm not saying that anyone's starter is "wrong." If it makes good bread, it's good starter! I'm just looking for a handy way to easily communicate how thick or thin a recipe writer thinks established starter should be, so that if my starter isn't that consistency, I know right off the bat if I'm going to need to add more flour or more water to the rest of the dough. It's not that I can't just watch during mixing and add flour or water as necessary. I just prefer, much of the time, to dump ingredients in the bread machine bucket and only check them once or twice, not baby-sit them for 10-12 minutes of slow but thorough mixing and kneading. If I have a right idea about adjusting consistency, I'll have extra flour or water handy, and after a few minutes I can start sprinkling it in until the dough comes together correctly. The bread was still good, though; I had toast from it for breakfast. I think some of it is destined to be sourdough garlic bread. :-) Matt, I think I avoided that same organic chemistry course... I haven't gone back and looked - did I mis-state the weight of flour this morning? I'll lay it all to the extra-early hour and a foggy brain! Thanks for all this good information. Now that it's the other end of the day (5:30 p.m.), I'm getting foggy again... But at some point I may think this all through. Or maybe I'll just keep using 8 ounces of starter and adjusting the consistency of the dough if I think it needs it. At any rate - thanks again for you great input. PJH

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