Many Jacob Bromwell products are made from stainless steel, and stainless steel is susceptible to forming rust spots over time. Using a rusted flour sifter or rusted cheese grater is 100% safe, despite what most people might think about rust. If you wish to remove the rust from your Jacob Bromwell product, they recommend that you use steel wool and/or an abrasive sponge and scrub with soap and warm water. This method is generally effective at removing minor to moderate rust spots from Jacob Bromwell products.