Re: How does the quality of water effct the baking process?

Dear Brian,

water quality is clearly important to baking results.  Let me begin by 
directing you to an excellent book: 

On Food and Cooking : The Science and Lore of the Kitchen by Harold McGee

I do not have a copy nearby, but he discusses cooking from a scientific 
perspective to assist one in understanding verious processes in cooking.
You can find info on this book at www.amazon.com

Baking results are intimately tied to very delicate chemistry.  I'm 
certain that in your program, you will have the opportunity to see what 
happens to bread if you leave one ingredient (such as salt) out.  
Generally, the two problems you will find with water used in baking are:

1)  pH

pH is related to the acidity or basicity of the water and can be measured 
with an ink impregnated paper called litmus...red is acidic and blue is 
basic, I recall.    At non-neutral pH (ultra pure water should be a touch 
acidic from the dissolved CO2 in the water, which forms carbonic acid 
H2CO3), you will probably inhibit the actions of the yeast on flour, 
causing a more dense loaf (since fewer CO2 bubbles are expelled by the 
yeast since it isn't "eating" so much flour).

2)  water hardness

hardness is the level of dissolved minerals (usually salts...sodium 
chloride, potassium chloride, sodium fluoride, etc) in the water.  High 
levels of minerals will probably alter the flavor of the bread (have you 
ever tasted reallyreally hard water?).  Additionally, if the water is too 
hard, it might affect the dough conditioning and the yeast action.  

Basically, the trick to baking is to have the right dough texture (too 
stiff and the CO2 formed by the yeast will not be able to stretch the 
dough out in rising, leaving a dense loaf...too loose and the bubbles 
won't be evenly distributed, will coalesce into big bubbles and 
pop...leaving exploded bread) and lively active yeast.

I hope this helps.  Please feel free to email me with further questions at:
weibelm@battelle.org

Best Regards,
Mike