The process of heating a solid fat, such as lard or suet, over low heat in order to melt it and separate out any impurities, such as bits of meat or skin. The impurities are often separated by decanting or filtering the liquid fat. Rendering is often used to make clarified butter or ghee, as well as to prepare lard or tallow for cooking. The end result of rendering is a clear, pure fat that can be used for a variety of culinary purposes.

How to Render Fat

  • Cut the fat into small pieces and place them in a heavy-bottomed pan over low heat.
  • Allow the fat to melt slowly, stirring occasionally to ensure that it melts evenly.
  • As the fat begins to melt, impurities will rise to the surface. Skim them off with a spoon. Other impurities will sink to the bottom of the pan. Leave them undisturbed.
  • Continue cooking the fat over low heat until all of the impurities have been removed and the fat is clear and pure.
  • Once the fat has been rendered, strain it through a fine-mesh sieve or cheesecloth to remove any remaining solids.
  • Allow it to cool before storing it in an airtight container.

Why Render Fat?

Rendering fat helps to remove impurities, such as bits of meat or skin, or milk solids in the case of clarified butter (ghee). These impurities can give the finished product an off flavor.

Rendering also helps to clarify the fat, which makes it more stable and less likely to go rancid. Rendered fat will have a longer shelf life and can be stored for longer periods of time without spoiling.

Additionally, rendering fat can help to improve its flavor and texture, making it more suitable for a variety of culinary uses. For example, clarified butter and ghee have a more delicate, nutty flavor than regular butter. This makes them ideal for sautéing and baking. Similarly, rendered lard and tallow have a high smoke point, which makes them well-suited for frying and roasting.

Clarified butter is butter that has been rendered to separate out the milk solids. Ghee is clarified butter that is simmered long enough to also evaporate out most of the water. This transforms butter from a refrigerated product with a short shelf life and every low smoke point into a shelf-stable one that will store for months in a cool dark place, with a very high smoke point.

Equipment Concerns for Rendering

To render fat, you will need a heavy-bottomed pan, such as a Dutch oven or cast iron skillet, and a heat source, such as a stovetop or oven. An induction burner is also a good choice. You will also need a spoon or spatula for stirring the fat as it melts, and a fine-mesh sieve or cheesecloth for straining the rendered fat.

Rendering fat is an outstanding way to improve the seasoning on a cast iron pan. Because you are cooking a large volume of fat for a long time, it penetrates pores and gaps in your existing seasoning. When finished rendering, simply clean and dry the pan, then heat it, ideally upside down in an oven, to the smoke point of your fat. This is a great first project for a new, or newly re-seasoned, cast iron pan.

Additionally, you may want to have a container on hand for storing the rendered fat once it has been processed. Canning jars are usually a good choice. If you are working with a large quantity of fat, you may need a larger pan or multiple pans to accommodate it all. Other useful tools for rendering fat include a kitchen thermometer, which can help you to monitor the temperature of the fat as it melts, and a skimmer, which can help you to remove impurities that rise to the surface.