Maximum Protein Purity
Top Sirloin Steak Protein & High-Protein Lean Macro Calculator
Grass-fed Top Sirloin is the champion of lean beef protein, delivering 6.65g of protein per raw ounce (23.5g/100g) and concentrating to 8.9g of protein per cooked ounce (31.5g/100g). Over 78% to 82% of its total calories come directly from bioavailable protein with minimal intrinsic fat.
A 10 oz raw Top Sirloin provides 66.5g of pure complete protein and 5.65g of L-leucine for only ~400 total calories, making it the supreme choice for athletic body recomposition, cutting phases, and maximum nitrogen retention.
🥩 Argentine Grass-Fed Sirloin
Pampas-Raised Top Sirloin: 80%+ Pure Protein Caloric Purity
Direct from the celebrated Argentine pampas, our 100% grass-fed Top Sirloins deliver unmatched lean protein density, robust mineral-rich beef flavor, and buttery tenderness without the heavy caloric load of grain-fed steaks.
66.5g Protein / 10 oz Cut
Ultra-dense essential amino acids with only ~15g natural pasture lipids.
Loaded with Creatine & Zinc
Naturally boosts muscular power, workout recovery, and testosterone synthesis.
100% Pasture Finished
Zero grain feed, zero antibiotics, zero growth hormones—ever.
100% Grass-Fed & Pasture-Raised • Flash-Frozen at Peak Freshness • Zero Added Hormones
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Fast-Twitch Muscle Architecture
Top Sirloin is carved from the gluteus medius primal. Its high density of Type II glycolytic muscle fibers delivers exceptional concentrations of glutamine, creatine monohydrate, and L-carnitine for rapid cellular repair.
Caloric Efficiency for Cutting
With less than 1.5g of fat per raw ounce, Top Sirloin enables bodybuilders and athletes to consume 60g+ of pure protein in a single sitting while saving 300+ kcal compared to heavily marbled cuts.
Top Sirloin Portion Macro Matrix
| Raw Portion Size | Cooked Plated Mass | Total Protein | Intrinsic Fat | Total Calories | Protein Purity |
|---|---|---|---|---|---|
| 6 oz Raw Cut | 4.7 oz (133g) | 39.9 g | 9 g | 241 kcal | 81% |
| 8 oz Raw Cut | 6.2 oz (176g) | 53.2 g | 12 g | 321 kcal | 81% |
| 10 oz Raw Cut | 7.8 oz (221g) | 66.5 g | 15 g | 401 kcal | 81% |
| 12 oz Raw Cut | 9.4 oz (266g) | 79.8 g | 18 g | 482 kcal | 81% |
Lean Steak Cooking & Tenderness Rules
- 1. Never Cook Beyond Medium-Rare (130°F): Because lean Top Sirloin lacks insulating fat buffers, cooking past 135°F causes rapid moisture expulsion. Pull at 125°F.
- 2. Sear Hot and Fast in Pure Beef Tallow: Use high-smoke-point grass-fed tallow in cast iron to achieve a crisp caramelized Maillard crust in just 90 seconds per side.
- 3. Rest 6 to 8 Minutes Before Carving: Resting allows myofibrillar proteins to relax and reabsorb sarcoplasmic juices.
Chef & Nutritionist Troubleshooting Protocol
Issue: Top Sirloin feels tough or chewy
Cause: Cooked to medium-well (150°F+) or sliced parallel to muscle fibers. Fix: Pull at 125°F and slice strictly across the grain at a 90° angle.
Issue: Surface graying without forming a dark sear
Cause: Surface moisture steaming in the pan. Fix: Pat completely dry with paper towels and dry brine uncovered in the fridge for 12 hours.
Frequently Asked Questions
Is Top Sirloin good for muscle building?
Yes. Top Sirloin delivers one of the highest protein-to-calorie ratios of any whole food (~80% protein calories) alongside high natural concentrations of creatine and zinc.
How much protein is in an 8 oz Top Sirloin steak?
An 8 oz raw grass-fed Top Sirloin contains 53.2g of pure protein and 4.5g of L-leucine for ~320 calories.
What is the difference between Top Sirloin and Sirloin Tip?
Top Sirloin (gluteus medius) is a tender, premium primal steak suitable for quick high-heat grilling. Sirloin Tip is from the round primal and is leaner and best suited for braising or thin slicing.
Why choose Argentine grass-fed Top Sirloin?
Argentine cattle roam year-round on lush pampas grasslands, developing exceptional natural tenderness and rich mineral flavor without grain finishing.
Fuel Your Muscle Goals with Argentine Grass-Fed Sirloin
Stock your freezer with pristine, lean, protein-packed Argentine Top Sirloin steaks delivered directly to your doorstep.
100% Grass-Fed & Finished
Zero Hormones or Grain Feed
Rancher-Direct Flash Frozen Delivery
