Yellow Grease Versus Brown Grease and How it Affects Recycling
If you're interested in helping the environment and making some extra money by recycling your restaurant's waste grease, you'll need to know the difference between yellow grease and brown grease — this affects their suitability for recycling. To learn more about the types of waste grease in restaurants, read on.
Yellow grease primarily comes from the vegetable oil that restaurants use in their deep-fryers. When the oil gets old and needs to be changed in order to avoid imparting off-flavors to fried food, it's placed into a waste oil canister. The waste oil canister has a grate on the inlet funnel that separates solids from the vegetable oil, so the oil kept inside the container is kept pure.
Since yellow grease is mostly free from contaminants, recycling it is simple. Most recycled yellow grease is shipped to agricultural companies to use as food for livestock, but it can also be processed and used for biofuel. Biofuel power plants, for example, are able to turn large amounts of yellow grease into electricity. Due to the fact that yellow grease requires minimal processing in order to be reused, bulk yellow grease is valuable in the recycling market.
Brown grease is what's collected from restaurant grease traps, whether they're under the dish pit or located underground. It consists of a variety of fats, including both animal fat and vegetable oil, and it also contains a significant amount of solids from the food waste that's flushed down the drain. Other contaminants can be present in brown grease as well, like soap or cleaning chemicals used in the dish pit.
Unfortunately, brown grease is recycled less often than yellow grease. The fact that brown grease contains food waste solids means that it's a breeding ground for bacteria, so it's heavily contaminated and dangerous to handle. The presence of chemical contaminants adds to the difficulty of recycling it successfully.
In the past, most brown greases were simply taken to landfills and buried, where they will break down into the soil over a long period of time. Thankfully, grease recycling options for brown grease are becoming more common. Brown grease can be rendered in order to separate all of the solids from the usable grease, and that grease can be used as biofuel. However, this requires more processing than yellow grease, so recycling companies purchase brown grease at a lower price.
If your current grease recycling service is taking your brown grease to the landfill, you may want to switch to one that will recycle it. While you won't receive as much money for your brown grease as you will for your waste vegetable oil from deep frying, you'll at least be able to make a small amount of extra money every time you need to clean out your restaurant's grease trap.