Walnuts equilibrate at less than 6 % moisture, which frees them from water activity. Walnuts baked at normal temperatures do well and do not burn.
Toasting walnuts enhances their flavor and adds crunch. It may also change the texture and affects their freshness, so once toasted, walnuts should be used quickly.
Walnuts work well with sugar and other ingredients in the mix.
Walnuts should be incorporated into the mix towards the end to prevent breaking them up more than needed.
The normal time frame for baked goods on the grocery shelf allows walnuts to move through the system before they oxidize. If longer shelf life is required, antioxidants may be added to extend product life.
Walnut flour is an increasingly popular ingredient in baking applications since it is easy to add to any baked good (simply mix in) and enhances the taste, flavor and water-binding capacity. Remember that walnuts are best when freshly ground. When grinding, be careful as they turn into butter very quickly – use a little flour or sugar in the recipe while grinding.
When using walnuts for quick breads, chop more finely than for yeast-leavened baked goods. Also, walnuts do not affect the gluten structure of breads.