How to Make Bone Marrow Butter

Bone marrow is the fatty tissue inside bones. In grass-fed animals raised properly, this marrow is rich in fat-soluble vitamins (A, D, K2, E)¹, cholesterol for hormone production, and compounds that support brain function and immune health. When mixed with butter, it becomes a spread that tastes decadent and carries more micronutrients than most vegetables.

What bone marrow actually is

Bone marrow serves two functions. Red marrow produces blood cells and immune cells. Yellow marrow is mostly fat, and that's what you're after for eating.

When an animal is young, most of its marrow is red. As it ages, more converts to yellow. Grass-fed cattle tend to have nutrient-dense, golden-coloured marrow. Grain-fed cattle produce whiter, less nutrient-concentrated marrow. This is worth knowing when sourcing.

Your ancestors ate marrow. Regularly. Not as a delicacy. As a staple. The best parts of an animal were the organ meats and the marrow. The muscle meat was sometimes a side dish.

Modern culture has flipped that hierarchy on its head. We've made muscle meat the prized cut and thrown away the organs and bones. That's a recent development. For most of human history, if you killed an animal, you ate every nutrient-dense part. Marrow was a treasured source of calories and fat-soluble vitamins.

Why you should eat it

Fat-soluble vitamins: A, D, K2, and E. Most people are deficient in these. They live in fat, not in water, so eating fat from well-fed animals is how you obtain them. Marrow from grass-fed animals is concentrated in these.

Cholesterol: Your brain is 25 percent cholesterol.² Your hormones are built from cholesterol. Your immune system uses cholesterol. The anti-cholesterol propaganda of the last 40 years has left people needlessly deficient. Marrow is one of the richest sources.

Bone health: The marrow doesn't directly strengthen bones, but the nutrients it contains (especially K2) direct calcium into the bones and away from soft tissue calcification (a major driver of heart disease).³

Brain function: Marrow carries compounds that cross the blood-brain barrier and support cognitive function. If you have brain fog, poor memory, or difficulty concentrating, marrow butter is worth trying.

• Rich in conjugated linoleic acid (CLA), which supports body composition and immune function.
• Contains stem cells and growth factors that may support healing (though research is ongoing).
• Tastes absolutely luxurious on sourdough bread or melted over steak.

Sourcing and preparing bones

Head to a butcher counter. Ask for grass-fed beef marrow bones. Not frozen from the supermarket. A real butcher. Tell them you're going to roast them. They'll probably slit them lengthwise (called "frenching") to make scooping easier.

Ask about the animal's diet. If they don't know, try another butcher. You want grass-fed, ideally finished on pasture. If the butcher says "grass-fed and grain-finished", that's still better than grain-fed, but not ideal. The final diet matters significantly for nutrient density.

Buy 2-3 bones per person. They're inexpensive (often given away or sold for a few pounds). Transport them home in a bag. Refrigerate if using within two days. Freeze if keeping longer (they'll last frozen for months).

Method

Makes roughly 100 grams of bone marrow butter. Takes 30 minutes active time, plus cooling.

1. Preheat your oven to 200°C. Line a baking tray with parchment paper or foil.
2. Place the marrow bones on the tray, cut-side facing upward if they've been split. If they're whole bones, you can roast them as is. You'll scoop from the end.
3. Roast for 15-20 minutes. The marrow will soften and may start to leak slightly from the ends. Don't panic. That's correct. You're looking for the marrow to be soft enough that a spoon or small knife can easily scoop it out, but not so hot that it's liquefied.
4. Remove from the oven and allow to cool for 5 minutes. The bones will be very hot.
5. Using a small spoon (a grapefruit spoon works perfectly), scoop the soft marrow from inside the bone. If the bone was split, the marrow will come away easily. If whole, scoop from the exposed end.
6. Place the scooped marrow in a small bowl. It should have the texture of soft butter.
7. Add 100 grams of soft grass-fed butter (unsalted) and mix thoroughly with a fork until combined. The mixture should be uniform and creamy.
8. Optional additions: a small pinch of sea salt, a few drops of lemon juice, finely chopped fresh parsley or thyme, a crack of black pepper. Mix if adding.
9. Spoon the marrow butter into a small jar or directly onto a piece of parchment to cool and solidify. Refrigerate for up to two weeks, or freeze for months.

The roasting time varies with bone size. Smaller bones take 12-15 minutes. Large beef femurs can take 20-25. You're looking for soft, not liquid. Err on the side of less time. You can always return them to the oven.

Ways to use it

• On sourdough bread: This is the classic. Thick slice of sourdough, generous dollop of marrow butter, small pinch of sea salt. That's the entire meal.
• Melted over steak: The marrow butter melts over hot meat and creates a rich sauce. No cream needed.
• Mixed into mashed vegetables: Mashed potatoes, mashed parsnips, mashed butternut squash. The marrow butter makes them taste decadent.
• Swirled into bone broth: A teaspoon of marrow butter in hot bone broth transforms it into something luxurious.
• On roasted vegetables: Whilst hot vegetables are still steaming, dollop marrow butter on top and let it melt.
• In pastry: If you make pie crust or shortbread, marrow butter can replace some of the regular butter. The result is incredibly tender.

The bottom line

Bone marrow is ancestral food that most people have abandoned out of unfamiliarity rather than genuine aversion. Roast some bones, scoop the marrow, mix it with butter, and taste it on good bread. You'll understand immediately why your ancestors prized it. It tastes luxurious, it makes you feel deeply satisfied, and your body recognises it as medicine. That combination is rare.

References

1. 1. National Institutes of Health, Office of Dietary Supplements. Vitamin K: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/ See also Vitamin A, D, and E fact sheets [accessed May 2026].
2. 2. Dietschy JM, Turley SD. Cholesterol metabolism in the brain. Current Opinion in Lipidology. 2001;12(2):105-112. https://pubmed.ncbi.nlm.nih.gov/11264981/
3. 3. Maresz K. Proper calcium use: vitamin K2 as a promoter of bone and cardiovascular health. Integrative Medicine. 2015;14(1):34-39. https://pmc.ncbi.nlm.nih.gov/articles/PMC4566462/