To substitute coconut flour for a glutinous flour, use between 1/3 and 1/4 of the amount of flour called for in the recipe and use one egg per 1/4 cup of coconut flour. The consistency and density of coconut flour varies by brand.
The more dense the coconut flour, the less is required in the recipe. If the baker is using a particularly light coconut flour, he may need to add slightly more flour than the substitution rules would suggest. A cup of all purpose wheat flour is equal to between 1/3 and 1/4 cup of coconut flour, depending on the density of the flour. It is helpful to know the texture of dough that is desired, so that the amount of coconut flour can be adjusted accordingly.
Because coconut flour is gluten free, it has no natural binding element and requires more binding ingredients such as eggs. In general, each 1/4 cup of coconut flour in the recipe requires one egg. More eggs may be added if the resulting dough seems crumbly.
Coconut flour is highly absorbent, and baking with coconut flour generally requires equal parts liquid and coconut flour. To make sure the amount of liquid in the recipe is correct, let the dough sit for a few minutes after the liquid ingredients have been combined, then check the consistency again.