Sweet iron has a sweet taste like that of sugar, creating moisture to give a wet and therefore soft mouth. Sweet iron as it rusts, will then begin to oxidize, allowing the metal to constantly have that same sweet taste.  JP Korsteel Sweet Iron French Link Eggbutt Snaffle Bit features: help prevent the horse from getting their tongue over the bit.  sweet taste encourages a wetter and softer mouth.  Bit strength: fairly mild Features of JP Korsteel: Provides the ultimate comfort for your horse. eliminates the 'Nutcracker' tongue pinching action. keeps the bit from hitting the roof of the horse's mouth. no direct pressure is applied to the tongue and bars. replaces bit interference with humane content. for effective communication between the horse and the rider. Please note: Sweet iron is made from black iron and copper, creating a metal that promotes moisture in the horse’s mouth. The black iron and copper compound slowly causing oxidisation and rust.  Slow-acting and harmless to horses, the oxidation has a sweet taste which the horse likes and which encourages salivation.  This metal will almost always discolour. The cheeks and joints of the bits are made from stainless steel which will not rust. A bit made of sweet iron will last for years and year and the rust will not flake off or harm the horse. The moisture in the air will also cause it to rust in the same way as it does with salvia. The only way to prevent this from happening is to store the bit in a heated environment. You can easily rub the bit down with very fine sandpaper which will remove the rust and will have no adverse effects on the bit or its use. We would also recommend washing the bit after every use but make sure that it is dried thoroughly. You can also coat it with vegetable oil when not in use again to slow the oxidization process down.