So I'm a bit of a scientist, who enjoys a bit of cooking and baking. My favorite bread is sourdough, but no place in my area sells it. So recently I've started a sourdough starter, and I'm waiting for it to mature before baking a loaf. Now my biggest complaint about sourdough is how fast it loses flavor after baking, generally within a couple days. This is because the acids present in the bread (mainly acetic acid, or vinegar) start to break down, causing the bread to lose its sour flavor. Science time! When you take calcium carbonate (which is found naturally as the main ingredient of egg shells, or of the common rocks limestone or marble) and dissolve it in vinegar (acetic acid) the carbonate breaks into water and carbon dioxide, and the calcium and vinegar bond to form calcium acetate. When the water evaporates away you're left with soft white crystals that are very hygroscopic (absorb water readily) and have a sharp, vinegary taste. This substance is perfectly safe, since it's just calcium (which is good for you) and vinegar (which is good for you and tasty). Calcium acetate is used as a "buffer" in a variety of foods, mainly sour candies and breads. As a buffer, it helps to preserve the pH level of the food; as acids present in the food break down, the calcium acetate breaks into calcium and acetic acid, and the acid lowers the pH back to its previous levels. The calcium, of course, is good for your bones. Thus adding calcium acetate to sourdough bread should keep the pH level low, thus keeping the bread sour longer. Here's the problem--I've never added Ca-acetate to anything before and I'm not sure how much to add or when in the baking process to add it! I'd also like to add calcium propionate, a similar substance which inhibits mold growth (this you have to buy, it's far too difficult to make on your own the way you can make Ca-acetate). So what's the process? Do you add it in when kneading it? Sprinkle it on after it rises? Or should it be added to the starter? If anyone has any experience please share! Also, if you're feeling adventurous you could try experimenting to find out. I'll be experimenting myself once I have enough starter to make a few loaves. Help and comments would be greatly appreciated!