Welcome to the Wonderful World of Meat!

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Welcome to the Wonderful World of Meat!
Compiled by Justin Wiebers, Extension Agent, 4-H,
University of Tennessee Agricultural Extension
Service
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Quality Grades

• Quality grades reflect the flavor and tenderness
  of meat and are primarily determined from carcass
  maturity and the amount of fat within the meat
  (i.e. marbling or intramuscular fat).

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USDA Quality Grades for Beef

• USDA Prime
• USDA Choice
• USDA Select
• USDA Standard
• USDA Commercial
• USDA Utility
• USDA Cutter
• USDA Canner

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Official USDA Marbling Photos
Moderately Abundant
Slightly Abundant
Moderate
Modest
Small
Slight
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Official USDA Marbling Photos
USDA Prime Prime grade beef is the ultimate in
tenderness, juiciness, and flavor. It has
abundant marbling -- flecks of fat within the
lean -- which enhances both flavor and juiciness.
Prime roasts and steaks are unexcelled for
dry-heat cooking (roasting and broiling)
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Official USDA Marbling Photos
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Official USDA Marbling Photos
USDA Choice Choice grade beef has less marbling
than Prime, but is of very high quality. Choice
roasts and steaks from the loin and rib will be
very tender, juicy, and flavorful and are, like
Prime, suited to dry-heat cooking. Many of the
less tender cuts, such as those from the rump,
round, and blade chuck, can also be cooked with
dry heat.
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Official USDA Marbling Photos
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Official USDA Marbling Photos
USDA Select Select grade beef is very uniform in
quality and somewhat leaner than the higher
grades. It is fairly tender, but, because it has
less marbling, it may lack some of the juiciness
and flavor of the higher grades. Only the tender
cuts should be cooked with dry heat. Other cuts
should be marinated before cooking or cooked with
moisture to obtain maximum tenderness and flavor.
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Official USDA Marbling Photos
Standard and Commercial This grade of beef
frequently is sold as ungraded or as "brand name"
meat. The three lower grades -- USDA Utility,
Cutter, and Canner -- are seldom, if ever, sold
at retail but are used instead to make ground
beef and manufactured meat items such as
frankfurters
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Maturity
The age of a beef animal has a direct effect on
tenderness of the meat it produces.  As cattle
mature, their meat becomes progressively tougher.
To account for the effects of the maturing
process on beef tenderness, evaluations of
carcass maturity are used in determining USDA
Quality Grades.  There are five maturity
groupings, Designated as A through E
below. Approximate ages corresponding to each
maturity classification are A - 9 to 30 Months
B - 30 to 42 Months C - 42 to 72 Months D -
72 to 96 Months E - More Than 96 Months
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Official USDA Quality Grades
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USDA Beef Quality Grades
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Yield Grades
USDA yield grades identify the "quantity" or
"cutability" differences among carcasses. Yield
grades are 1, 2, 3, 4 and 5, and are a numerical
representation of the expected percentage of
closely trimmed, boneless retail cuts from the
round, loin, rib and chuck. This percentage of
retail cuts is the carcass cutability
Boneless, Closely Trimmed Retail Cut Yield Grade
From the Round, Loin, Rib and Chuck 1 52.6
- 54.6 2 50.3 - 52.3 3 48.0 -
50.0 4 45.7 - 47.7 5 43.3 - 45.4
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Yield Grades

• Carcass factors used to calculate yield grade
• Adjusted fat thickness
• Percentage of Kidney, Pelvic and Heart Fat (KPH)
• Rib Eye Area
• Hot Carcass Weight

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Adjusted Fat Thickness
External fat is measured at the 12th rib
perpendicular to the outside fat at a point 3/4
the length of the rib eye (longissimus) muscle.
This measurement may be adjusted by the grader to
reflect unusual fat distribution in the carcass.
Special attention is given to fat deposition in
the cod or udder, rump, inside round, flank,
lower rib, plate and brisket areas. External fat
is the most important yield grade factor. As
external fat increases, the percentage of retail
cuts decreases.
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Percentage of Kidney, Pelvic and Heart Fat
This is a subjective estimate of the amount of
fat surrounding the kidney knob, and fat in the
pelvic and thoracic (heart) areas as a percentage
of the carcass weight. As the percentage of KPH
fat increases, the percentage of retail cuts
decreases. Percentage KPH fat normally ranges
from 1.0 to 4.0 percent.
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Rib Eye Area
The longissimus muscle is measured at the 12th
rib by using a grid expressed in square inches,
or a compensating polar planimeter, which
measures a rib eye tracing. Rib eye area is an
indicator of carcass muscling as rib eye area
increases, retail cut yield increases.
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Hot Carcass Weight
Generally, as carcass weight increases, the
percentage of retail cuts decreases slightly due
to increased fat deposits. If only chilled
carcass weight is available, it can be adjusted
to hot carcass weight by multiplying by 1.02 to
correct for the evaporative weight loss of the
carcass in the cooler.
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Calculating Yield Grade

• Yield grades are calculated by using the
  following formula
• YG 2.50
• (2.50 Adjusted Fat Thickness, inches)
• (0.20 Kidney, Pelvic and Heart Fat )
• (0.0038 Hot Carcass Weight, lb)
• - (0.32 Rib eye area, sq. in.)

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Calculating Yield Grade

• For example, a carcass has 0.40 inch of fat, 2.5
  percent KPH, 12.8 sq. inches of rib eye and a hot
  carcass weight of 750 lbs. Substitute these
  variables into the yield grade equation to
  calculate a final yield grade of 2.75
• YG 2.50 (2.50 0.4 in.)
• (0.20 2.5 percent)
• (0.0038 750 lbs.)
• - (0.32 12.8 sq. in.)
• YG 2.75