Simmering Granule salts Simmering Granules are a natural salt based product with added colour and fragrance for use in oil or wax burners. Scented Sizzlers are safe, clean and simple to use. What are Simmering Granules? Simmering granules are in fact salt granules which have been infused with colour and fragrance. These salts are the perfect size for simmering granules. This is a food grade product of the highest quality. 5kg comes in a grip seal bag.