Inside Skirt vs Testicles — What's the Difference?
Quick Answer
Inside Skirt (inside skirt steak) and Testicles (testicles (criadillas/Rocky Mountain Oysters)) are not the same cut: Inside Skirt is plate primal (Transversus abdominis muscle — the inner diaphragm muscle); Testicles is offal primal (Removed at castration — sold as a standalone cut).
Canonical entities: Inside Skirt · Testicles
Side-by-side
| inside skirt | testicles | |
|---|---|---|
| Primal | plate | offal |
| Muscle / location | Transversus abdominis muscle — the inner diaphragm muscle | Removed at castration — sold as a standalone cut |
| Character | The 'other' skirt steak. Thinner, wider, and slightly tougher than the outside skirt (which is the standard 'skirt steak'). Most restaurant fajitas use inside skirt because the outside skirt is exported or sold at premium. Requires high heat, fast cooking, and slicing against the grain. | Bull testicles. Sold and prepared as a standalone cut across multiple cultures. Known as criadillas in Spain and Latin America, Rocky Mountain Oysters in the US west, and Prairie Oysters in Canada. Typically peeled, sliced, and deep-fried or grilled. |
Key differences
- Different primals: plate vs offal.
- Texture and slicing: compare fibrous, grain-heavy cuts vs more tender steak-style muscles based on each cut’s description.
- Retail naming diverges by country—always map through a canonical cut when translating menus or labels.
When to use each
Inside Skirt
Pick Inside Skirt when you want its specific marbling/texture profile: The 'other' skirt steak. Thinner, wider, and slightly tougher than the outside skirt (which is the standard 'skirt steak'). Most restaurant fajitas use inside skirt because the outside skirt is exported or sold at premium. Requires high heat, fast cooking, and slicing against the grain.
Testicles
Pick Testicles when its primal/muscle traits fit the dish: Bull testicles. Sold and prepared as a standalone cut across multiple cultures. Known as criadillas in Spain and Latin America, Rocky Mountain Oysters in the US west, and Prairie Oysters in Canada. Typically peeled, sliced, and deep-fried or grilled.
Inside Skirt and Testicles are different canonical muscles/primals: Inside Skirt is plate (Transversus abdominis muscle — the inner diaphragm muscle); Testicles is offal (Removed at castration — sold as a standalone cut).
Choose based on tenderness, marbling, grain direction, and how you plan to cook (sear vs braise vs slice thin).
Read the full guides: inside skirt (what-is) · testicles (what-is) · inside skirt hub · testicles hub