GRASS-FED BEEF RESEARCH SERIES | RESEARCH PAPER
Harvest Age, Grind Specification, and Named-Primal Grinds
Three attributes that materially change what a ground-beef buyer receives — and that almost no producer discloses. The survey figures cited come from FAT’s national producer survey of 724 direct-market operations, observed August 26–27, 2026.
Prepared for publication by Farm Animal Transparency | August 2026
Producers readily disclose that a carcass hung 21 days; they do not disclose that the animal lived 32 months. Both are “aging.” Only one is treated as a selling point.
| At a glance |
| Of 724 direct-market producers surveyed, 9 (1.2%) state harvest age anywhere on their own site — while 112 (15%) advertise dry-aging. |
| 30 months is a regulatory cliff: at that age the FSIS specified-risk-material list (9 CFR 310.22) expands to include the vertebral column — so a T-bone or porterhouse cannot legally be cut from a 30-month-or-older animal, and, because USDA grades by physiological maturity, a Slight-marbling carcass that reads as B maturity (roughly 30–42 months) grades Standard instead of Select. |
| Grind specification — plate size, single vs. double grind — changes how ground beef binds, renders, and eats, yet is measured and reported nowhere; 2 of 724 producers mention it. |
| “Ground sirloin” guarantees provenance, not leanness: the FSIS primal-name rule requires the lean and the fat to come from that primal, but attaches no fat-percentage requirement. Surveyed named-primal grinds carried premiums of 6–66% over plain ground from the same animal. |
1. Harvest age — and why 30 months is a hard line
Grass finishing takes longer than grain finishing — typically 18 to 30-plus months against roughly 14 to 18. A "grass-finished" claim says nothing about where in that range an animal fell, yet a 20-month carcass and a 34-month carcass are different products in tenderness, flavor intensity, regulatory status, and which cuts can legally be made from them.
Disclosure is close to nonexistent. Of 724 producers surveyed, 9 (1.2%) state harvest age anywhere on their own site. By contrast, 112 (15%) advertise dry-aging. Producers readily disclose that a carcass hung 21 days; they do not disclose that the animal lived 32 months. Both are "aging." Only one is treated as a selling point.
The nine that do disclose: Wholly Cow Farms (AR) 18–24 months · Green Place Ranch (CO) 22–28 months · Hay Mama / P Bar Ranch (MT) 24–30 months · J-Boys Small Batch Beef (TX) "about 30–36 months" · Breezy Hill Farm (MO), which sells ground beef explicitly from animals "exceeding the 30-month USDA rule" · plus four with partial or non-beef age language.
Why 30 months is a regulatory cliff, not a preference. Under FSIS rules adopted after BSE (9 CFR 310.22), the specified risk material (SRM) list expands sharply at 30 months. Below 30 months, only the tonsils and distal ileum are SRM. At 30 months and over, SRM also includes the brain, skull, eyes, trigeminal ganglia, spinal cord, vertebral column, and dorsal root ganglia. SRM must be removed, segregated, and destroyed; it cannot enter human food. The vertebral column here excludes the tail vertebrae, the transverse processes of the thoracic and lumbar vertebrae, and the wings of the sacrum. FSIS treats an animal as 30 months or older when at least one of its second pair of permanent incisors has erupted, unless the plant has records documenting its age (FSIS Directive 6100.4).
The vertebral column matters commercially because the dorsal root ganglia — the nerve clusters of actual concern — sit inside it and cannot practically be separated from it.
The practical consequence is that a T-bone steak is a vertebra. The "T" is a cross-section of backbone, strip loin on one side and tenderloin on the other; a porterhouse is the same cut further back with a larger tenderloin. So from a 30-month-or-older animal:
- T-bone and porterhouse cannot be produced at all. The cut is definitionally the SRM.
- Bone-in ribeye and standing rib roast must have the chine bone (thoracic vertebrae) removed, yielding a semi-boneless version.
- Unaffected: ground beef, boneless steaks (boneless strip, boneless ribeye, tenderloin), and roasts. Tail vertebrae are specifically excluded from the SRM definition, so oxtail is unaffected.
And the grade falls too. USDA quality grade combines marbling with maturity, where maturity is judged physiologically — cartilage ossification along the vertebrae, plus rib color and shape — approximating age as A (≈9–30 months), B (≈30–42), C/D/E older. A and B are "young" cattle eligible for Prime, Choice, Select and Standard. But Select requires A maturity; B-maturity carcasses are not eligible for Select at all. An animal with Slight marbling grades Select at A maturity and drops to Standard at B.
This compounds badly for grass finishers specifically. Forage-only finishing takes longer and generally produces less marbling, so these carcasses cluster precisely in the Slight-marbling range where the A/B line decides Select versus Standard — while also being more likely to read at or past 30 months. Slow finishing is penalized twice: the loss of premium bone-in SKUs, and a grade drop independent of eating quality.
One producer models the right disclosure. Rafter W Ranch (CO, AGA- and Audubon-certified) publishes a customer-facing explainer titled "What Exactly Is a T-Bone Steak? (And Why We Sometimes Can't Cut One for You)." It is the clearest voluntary disclosure of this constraint found anywhere in the survey.
2. Grind specification — real, unregulated, unmeasured
Ground beef texture is set by the grinder plate hole diameter, and by whether the meat is run once or twice.
| Plate | Metric | Typical use |
|---|---|---|
| Kidney plate (3 large kidney-shaped holes) | — | Coarsest; first-pass breakdown, stew meat |
| 3/4" | 19 mm | Coarse breakdown |
| 1/2" | 12 mm | First grind |
| 3/8" | 10 mm | Coarse — chili grind, first grind for burger |
| 5/16" | 8 mm | Medium-coarse |
| 1/4" | 6 mm | Medium |
| 3/16" | 4.5 mm | Standard commercial hamburger grind |
| 1/8" | 3 mm | Fine — sausage |
| 1/16"–3/32" | 1.5–2.4 mm | Very fine, emulsified products |
Commercial burger is typically double-ground: a first pass through 3/8" or a kidney plate, then a second through 3/16". A coarse single grind through 3/8" alone produces the steakhouse-style texture. Same meat, materially different product.
Where grind specification is measured or reported: nowhere. It is not a required FSIS label element, it does not appear in USDA AMS reporting — including the National Grass Fed Beef Report and the weekly retail feature reports — and 2 of 724 surveyed producers mention it at all.
The gap matters disproportionately for grass-finished beef, which is leaner and whose fat renders differently under heat. Grind size drives how it binds, renders, and eats. A consumer paying a premium for grass-finished ground and receiving a fine commodity grind may get a worse result than the identical meat coarsely ground — with no way to know, compare, or ask.
3. “Ground chuck” and “ground sirloin” — a real standard, narrower than assumed
There is an enforceable FSIS labeling policy here, and it is worth stating precisely because the common consumer reading is wrong.
What the rule requires: when a ground product carries a primal name, both the lean and the fat must come only from that primal. Ground chuck must be chuck; ground sirloin, sirloin; ground round, round. That is real and enforceable.
What the rule does not require: any particular lean-to-fat ratio. No fat-percentage requirement attaches to the primal name. The only applicable limit is the general ground beef standard of 30% fat maximum (70% lean minimum). Market convention puts ground chuck near 80–85% lean and ground sirloin leaner, but that is convention, not regulation — a legally compliant "ground sirloin" could be 70% lean.
The name guarantees provenance within the carcass, not composition. The widespread consumer assumption that "ground sirloin" means "leaner" is not what the standard secures.
Related distinction: "ground beef" may not contain added fat; "hamburger" may. Both cap at 30% fat.
What producers charge for it. Twelve surveyed operations sell named-primal grinds. Where both a plain ground and a named-primal price are posted:
| Producer | State | Plain ground | Named-primal grind | Premium |
|---|---|---|---|---|
| Autumn's Harvest Farm | NY | $8.99/lb | Ground sirloin $14.95/lb | +66% |
| Crane Dance Farm | MI | $11.00/lb | Ground sirloin $18.00/lb | +64% |
| Kinloch Farm | VA | $13.00/lb | Ground sirloin $19.00/lb | +46% |
| Seven Sons Farms | IN | $12.60/lb | Ground sirloin $15.70/lb | +25% |
| Caitlyn Farms | NC | $9.00/lb | Ground chuck/brisket $11.00/lb | +22% |
| Green Fire Farm | WI | $9.75/lb | Ground round 95/5 $11.00/lb | +13% |
| Montana Better Beef | MT | $8.25/lb | Ground sirloin $9.30/lb | +13% |
| Riemer Family Farm | WI | $14.95/lb | 95% ground round $16.00/lb | +7% |
| BN Acres | NC | $7.00/lb | Ground sirloin $7.40/lb | +6% |
Premiums run 6% to 66% for the same animal, different primal. Only two of these producers state a lean percentage alongside the primal name — the rest ask the buyer to infer composition from a term that carries no compositional guarantee.
4. What this adds up to
Producers disclose the attributes that flatter them — dry-aging days, breed, "100% grass-fed" — and stay silent on the attributes that carry tradeoffs: harvest age, grind specification, and the actual lean content behind a primal name. That is not fraud. It is selective disclosure, and unlike most transparency complaints it is directly measurable. FAT will track harvest-age disclosure as a standing metric, and the FAT app now recognizes each of these three disclosures on a scanned label: a stated harvest age earns the Age at Slaughter category, a named-primal grind triggers a provenance-not-composition explainer, and a disclosed grind specification is flagged as the rare transparency it is.
Sources
- 9 CFR 310.22, “Specified risk materials from cattle and their handling and disposition” (eCFR)
- FSIS Directive 6100.4, verification instructions related to specified risk materials (age determination by dentition)
- USDA FSIS, Specified Risk Material resources (including Best Practices for SRM Removal)
- USDA AMS, Carcass Beef Grades and Standards (maturity groups; Select limited to A maturity)
- 9 CFR 319.15, ground beef and hamburger standards (eCFR)
- Texas A&M Meat Science, “Making Some Sense Out of Ground Beef Labeling” (FSIS primal-name policy; 70% lean legal minimum)
- Rafter W Ranch, “What Exactly Is a T-Bone Steak? (And Why We Sometimes Can’t Cut One for You)”
- Commercial grinder plate specifications, 1/16" through kidney plate (equipment vendors).
- Farm Animal Transparency national producer survey, 724 operations, observed August 26–27, 2026.
Companion paper: "Lean Beef in America: The Blended, Unlabeled Supply Chain Behind American Ground Beef" — the supply-chain side of the same story. Read it here.
Try it on your own package: the Hamburger Label Decoder applies this research interactively — answer what your label says and it decodes what each statement (and each silence) legally means.
More in the Hamburger Research Series
- What “American” Means on a Ground Beef Label
- Lean Beef Imports for Hamburger Sold in America
- Lean Beef in America
- Purchased Silence
- Is My Ground Beef Lab-Grown?
- Hamburger Label Decoder — work through your own package
Working paper. Revised October 20, 2026: added the age-determination rule and SRM exclusions, clarified that the maturity grade is physiological, labeled the grinder-plate table as trade practice and dated the posted prices, and linked the sources. Corrections welcome: dirkadams@farmanimaltransparency.com.