Yellow Grease, Used Cooking oil and Waste Vegetable Oil

Yellow Grease is a commodity in the United States that is produced by rendering companies and is typically comprised of used cooking oil and may contain rendered animal fats such as tallow, poultry fat or lard. Generally yellow grease must meet the following specification: FFA max 15% and MIU < 2% with 1% max water. MIU of 2% or below is commonly referred to as "clean and dry". When prices for yellow grease are indexed and published, one should consider whether the product meets the yellow grease specification. if it does not, then in our opinion, this is not "yellow grease" per se, rather the product is processed or refined UCO/WVO and these yellow grease indices should not be referenced solely as the basis for determining price, especially if filtration, reduced animal fat or low FFA is present in the product. All of these attributes increase the value of the product and one can typically expect to pay more for this than for yellow grease.

Used Cooking Oil (UCO): Used cooking oils collected from food factories, restaurants, bakeries, etc. and is also commonly referred to as waste vegetable oil, although it may contain significant amount of animal fats from cooking process. Product may be completely unprocessed (raw) and generally will contain elevated impurities, water and free fatty acid levels. In severe cases low grade unprocessed UCO product may contain bags, gloves, plastic, towels, and any other items which find their way into the collection bin. Additionally unscrupulous persons may dump used motor oil or paint/solvents in to the collection drum which effectively contaminate the oil and render it useless. The picture to the right at the top is very low quality UCO collected from restaurants and has no processing done to it. FFA was about 17% and has increased to 22 over time. Water contents is about 30% and is one of the causes for increasing FFA (water and heat can increase FFA by 1% or more per week). Pictured in the middle on the lower right is another UCO product. This is collected from closed loop restaurant oil systems and tends to be higher quality than UCO collected from drums and barrels, but has significant levels of animal fat and/or hydrogonated/saturated fats and oils. This product shows clear veg oil on top, and bottom layer of saturated/hydrogenated fats and oils. FFA is about 6-9% on this and MIU about 4%.