Excess Baking Powder

Tip for washing the brush:
For washing, use a neutral soap such as Marseille soap.
Be sure to rinse them with lukewarm water and dry them with a clean, dry microfiber cloth.
When you have finished washing your brushes, let them air dry overnight with the bristles facing down and never up.

Caution: NEVER let brush handles soak in water for too long as this could damage them.