Pro Tip: Water hardness and pH can impact yeast activity and dough strength.

As a bakery consultant, I am often asked about the effect of water quality and baking. Generally speaking, potable water is acceptable for use in baking, although the pH and mineral content can vary significantly depending on the source of water supply. In breads, water represents about 40% of the total dough mass. With the demand for extended shelf life, most bakeries rely on the use of dough conditioners and enzymes in their formulations, but do you know the quality of your water and why it matters?

What is functionality of water in the baking process?

  • Hydrates starch particles to begin dough formation.
  • Dissolves and combines the other ingredients, like salt, sugar and yeast.
  • Reacts with the proteins in flour to become gluten.
  • Catalyzes the enzymes to deliver their full functionality.
  • Controls the rate of yeast fermentation.
  • Triggers the Maillard reaction to form a crust color on your bread in the oven.

Does hard water affect the baking process?

Water hardness is usually expressed as the number of parts per million (ppm) of calcium carbonate present in the water.


Type of Water


Soft water

10–50 ppm

Slightly hard water

50–100 ppm

Hard water

100–200 ppm

Very hard water

Over 200 ppm









These minerals act as “food” that nourish the yeast in your dough during fermentation. Mineral content can also have a strengthening on your dough’s gluten.

Water hardness between 100 to 150 ppm is ideal for bread baking.

Soft water can limit fermentation and make the dough sticky and too extensible, and slow fermentation. Corrective steps you can take is to increase the level of yeast food.

Hard water above (>200 ppm) will speed up fermentation, cause the gluten to be too tight and will limit the volume on the breads. Bakers can correct this in a number of ways:

  • Increasing the yeast level.
  • Decreasing the amount of yeast food such as sugars/starch used since these contain minerals.
  • Reducing the amount of added dough improver since these also contain minerals.
  • Adding Sodium Hexametaphosphate (SHMP).
  • Using a water softener or osmosis water system.


Water for baking should have a pH just below 7.

pH level is also another important variable. Water is typically thought of as having a neutral pH (pH=7), and from my professional experience, I have seen tap water pH range from 4.5 to 10.

For baking, the ideal is water with a pH of just below 7.

To standardize the pH of water, phosphate buffers can be used to maintain the water pH to neutral. These ingredients are called Monocalcium Phosphate (MCP) or Monosodium Phosphate (MSP). It is important to consult with a water treatment company to ensure that any additions of new ingredients like phosphates will not affect or interact with the other ingredients.

Richard Charpentier is a classically trained French baker, CMB, holds a degree in baking science from Kansas State University, and is owner and chief executive officer of Baking Innovation. Connect with him on LinkedIn.