To most visitors to this site (USA, Canada, northern Europe, Australia, Great Britain) water is something we take for granted. We turn on the tap and there it is. Water, clear, splashing, fresh, safe. We can turn the tap this way or that and change the temperature of the water. However, water, as I have recently discovered, isn't quite that simple.
I had long thought that if your water is safe to drink, you could almost certainly make good bread, and even good sourdough bread, with it. However, as I learned, there are further issues.
The first is chlorination. While chlorine can interfere with the growth of yeast and sourdough bacteria, in practice, this is a very unusual occurrence. I have started, maintained, fed and used sourdough starters with chlorinated water in a number of different cities and had no problems resulting from that use of chlorinated water. However, some water systems use chloramines which are a more persistent form of chlorine and I have received some emails suggest that chloramines are very hard on the micro-organisms bakers depend on. Your water supplier can tell you how they treat the water they supply you.
Water hardness is a significant issue for some bakers. A friend commented that sometimes his dough is slacker than other days, and on those days he comments that "the water must be wetter than usual today." This is a sign of very soft water. Water hardness, or how much mineral content is dissolved in the water, is measured in parts per million (ppm) or milligrams per liter (mg/l). Both are, if my math is working, the same measure. You can call your water supplier and ask them about the hardness of the water. If they can't tell you, you can get inexpensive test kits from swimming pool supply companies. If your water is the 50 to 150 ppm range, your water is ideal for bread making. If your water has a lower level of hardness, it is soft water. If it has a higher level, it is hard water.
If you have soft water, your dough will lack cohesiveness. If you find yourself following recipes from different sources and always finding the dough is too soft, too slack and won't hold shape there is a chance you have soft water. There are a number of solutions, and (after our last move) we are investigating the matter. The simplest is to use a bit more salt to toughen the gluten.
If you have hard water, your dough will lack extensibility. There are a number of solutions for this, the easiest is to use softened, but not completely demineralized, water.
The last issue is pH, or the acidity/alkalinity of your water. Dough prefers to be made with water that is neutral to slightly acidic. Alkaline water causes dough to be very soft and unmanageable. You can use a hot tub or swimming pool test kit to determine the pH of your water.
If it seems you are having water related problems, you might look into how your local water is treated, and try some bottled spring water and see if the problems go away. You do not want to use distilled or reverse osmosis treated water because these treatments remove all minerals from the water and you do need some mineral content in your water. If the problems go away, you might look at how the bottled water differs from your tap water and whether you can make your tap water more like the bottled water.
For a while we just used bottled spring water worked and it worked well. We've had good results with Ozarka and Kroger's house brand.
Still, it bothered us that we had to buy overpriced water that was sold in non-recyclable bottles. So, we contacted >a href="https://www.aibonline.org/" target="_blank">AIB International. At one time they were known as the American Institute of Baking. They offer extensive training and are an excellent resource. After some talk, they suggested that we add .26% gypsum to our dough, and that pretty well took care of our water issues. The difference is immediate and dramatic - the difference between goo and dough!
The bottom line is, if you have good bread making water flowing from the tap in your house, thank your lucky stars and enjoy the water - and the bread!