What does rendering fat actually do?
Raw fat is a mix of pure fat, connective tissue and water. Rendering gently melts the fat out of the tissue, then separates it from the solids that remain. What is left after straining is the product people call lard when it comes from pigs and tallow when it comes from beef or mutton.
The water content matters more than most beginners expect. Fat that still holds moisture spoils sooner, and the goal of careful rendering is to drive off water and strain out solids so the finished fat is stable.
Plan on a messy, aromatic day. Rendering fills a kitchen with a strong smell, so many people do it outdoors on a side burner or in a well-ventilated space, which also keeps splatter off the stove.
Which fat should you start with?
Fat from different parts of the animal behaves differently. Soft fat from around the kidneys is often prized for baking because of its mild flavor, while back fat and trimmings have a stronger taste better suited to frying. Ask your butcher or the person who processed your animal which pieces you are getting.
Start with fat that was chilled promptly and kept clean. Fat from an animal that was processed under good conditions and held cold will render with a cleaner flavor than fat that sat warm or picked up dirt.
If you raise your own animals, talk with whoever processes them about saving the fat. Some processors discard it unless you ask, and some need to know ahead of time so it can be chilled and bagged separately.
- Keep fat cold until you are ready to work
- Trim off meat scraps, bits of skin and blood spots
- Cut into small, even pieces so it melts evenly
- Use only fat from animals that were healthy and inspected where required
How do you render it without scorching?
Low and slow is the rule. Fat melts out best over gentle, steady heat, either on a stovetop, in an oven or in a slow cooker. High heat can scorch the solids and give the fat a burnt taste that never goes away. Stir now and then and keep watch rather than walking away.
Your extension office can point you to a tested home rendering guide that gives the details for your method. Follow its heat guidance rather than relying on an old family habit, particularly if you plan to give or sell the finished fat.
A heavy pot with a thick bottom spreads heat more evenly than a thin one. Keep the pot no more than about half full so it does not boil over as the fat melts.
How do you strain and clean the fat?
When the fat has melted and the leftover bits look dry and golden rather than wet, pour it through a fine strainer or cloth into clean, heat-safe containers. Leave the cracklings behind. Many cooks save them as a snack or use them in cooking.
Clean containers are important. Wash and dry jars well, because a drop of water in the fat can lead to spoilage later. Work carefully, since hot fat can cause serious burns. Keep children and pets out of the kitchen while you work and never move a full pot in a hurry.
Let the fat cool somewhat before you pour so that it does not crack glass jars, but not so long that it begins to set in the strainer.
How should you store rendered fat?
Once the fat has cooled and set, cover it tightly and keep it cold. Many households store it in the refrigerator for regular use and freeze the rest in portions. Label each container with the type of fat and the date.
Do not assume fat is shelf stable just because it looks solid. Canning fat or storing it at room temperature involves real safety questions, so use a tested source such as the National Center for Home Food Preservation or your extension office for guidance before keeping any at room temperature.
Small jars work better than one large container, because every time you open a jar you let in air and moisture. Open only what you will use in a reasonable time.
How can you tell fat has gone bad?
Rancid fat smells sharp, soapy, painty or like old crayons. Fat that has picked up mold, shows a pink or green tint or smells sour should be thrown out. A small change in color is not always a problem, but a change in smell usually is.
If you are not sure, discard it. Cooking fat is inexpensive compared with the cost of an unpleasant meal, and oxidized fat is not something you want to serve.
Keep a small notebook of what you rendered, the source and what you noticed about smell and color. Over a few batches you will learn what normal looks like for your animals and your method.
What are the legal points to check before sharing or selling?
Rules for selling home-rendered fat differ by state and sometimes by county. Some places treat it like other processed meat products. Ask your state department of agriculture or local health department what applies to you, and whether the animal needed to be processed at an inspected facility for the fat to be sold.
Even if you give it away, label the container with the animal source and the date so the person receiving it knows what it is.
Key takeaways
- Start with clean, cold, well-trimmed fat from a healthy animal.
- Render slowly over gentle heat to avoid scorching.
- Strain well and store in clean, dry, tightly covered containers.
- Check state and local rules before selling any home-rendered fat.
Sources and further reading
Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.