Rocky mountain oysters are the original sack lunch, and a regional delicacy of the Rocky Mountain region and the American West as well as parts of Mexico and Canada.
They're an organ meat that's underappreciated, sure, but considering what part of the animal they come from that's easy to understand. As a chef trained in whole animal butchery eating nose-to-tail is the only logical thing for me to do.

Here I'm going to share with you everything I know about harvesting, processing and cooking this special organ meat.
Background
They're best known as Rocky Mountain Oysters, but, depending on the location they may go under different, colorful names. Here's a few examples:
- Bull fries or calf fries
- Bull’s eggs
- Montana tendergroins
- Swinging beef
- Prairie oysters
- Cowboy caviar
They're a local delicacy with a unique flavor still served in historic saloons, and an important part of American cowboy culture. There's even annual testicle festivals in North Texas, and Rocky Mountain Oyster day in Colorado.
Laugh all you want at the idea of communal nut frys and testy fests, but as long as they're prepared correctly these can be a delicious novelty dish. They're also one of the most inexpensive sources of food I know of, as pounds of bull testicles will cost about $4.99 each.
Full disclosure: I typically eat lamb fries as I have access to plenty, but the method for preparing and cooking here will apply to any similar animal.
Every animal tastes different
I've eaten pork testicles, as well as beef, goat, boar, lamb, duck and venison, and one thing I've learned is that some are an acquired taste, but not all.
Goat, lamb and boar have a strong gamey flavor, but pork and beef are mild, making them the best ones to start with if it's your first time, especially with a side of cocktail sauce or horseradish sauce.
Texture
The texture is one of the things that makes fries special. After your first bite, you'll notice they're meaty and firm, but soft, with a texture similar to a fine sausage or a hot dog. They have a different texture than most skeletal muscles.
If you or members of your family don't like offal like liver or kidneys, the firm texture makes these a good candidate for introducing people to offal, especially if you bread and fry them golden brown.
How to Prepare Rocky Mountain Oysters
Typically testicles are harvested from young bulls, spring calves or rams by cutting off the entire scrotum with a sharp knife. Ouch.
I butcher animals myself, so my pictures illustrate more of the process than others will. The only thing that's been done to the lamb testicles you'll see here is removing the furry scrotum after butchering, which peels off easily.
Removing the Membranes
Most testicles are going to come to you with the outer membrane removed. If all you have is the inner membrane attached, all you have to do is make a thin cut in the outer membrane, then peel it off to reveal the meat.
If you bought your fries, they probably won't have the thick membrane pictured below, so you can skip to par-cooking.
Remove the Outer membrane (if attached)
Removing the thin, inner membrane
Revealing the inner meat
Cooking
There's a variety of ways to cook your tasty testes. Typically they're peeled and cooked in water, then sliced, breaded and fried. They can also be pounded flat before breading.
Fried Rocky Mountain Oysters
If you want traditional Rocky Mountain oysters dredged in a flour mixture and fried, try my method for trimming. Then fry them up and pass the hot sauce.
Smoking
Smoking is a great alternative to frying. Put some slices out with cheese and cured meats and watch them disappear! If you want to try that, see my smoked rocky mountain oysters.
How to Cook Mountain Oysters
Equipment
- 1 Sharp paring knife
Ingredients
- rocky mountain oysters from lamb, beef or pork with outer sheath attached
- Milk or water optional
Instructions
Trimming fresh testicles
- Put the testicles on a cutting board and cut the ends off each one.
- Carefully remove the thick outer membrane.
- Make an incision in the thin inner membrane, then carefully peel the membrane back to reveal the inner meat.
- From here, the testicles can be cooked, breaded and fried, or prepared however you like.
To par cook (if the inner sheath sticks)
- Cover the testicles with 2 inches of water and bring to a simmer. Cook for ten minutes.
- After ten minutes, remove the testicles and cool until you can handle them. Then trim and remove the sheath and inner membrane.
Gary
Greetings. Have you ever tried to sous vide the testicles? I am trying to find information on time and temp. I would also like to wrap them in bacon (with the help of moo glue)....sous vide, and then fry or air fry to crisp the bacon. Your thoughts would be appreciated!
Alan Bergo
Hi Gary. Sous vide should work well. I would aim for 150 F for 2 hours. As for moo glue, are you referring to transglutaminase / meat glue? I avoid using conventional bacon as it's very thick and needs to be rendered crisp which is difficult with cylindrical forms. I would wrap them in prosciutto.