Quality Attributes (II)

In this section:

Grade & Yield
Canadian and U.S. Grading Comparison
Aging
Location of Cut
Trim Specifications

Aging

Beef, like fine wine, improves with age. The term aging simply means the length of time beef cuts are stored under controlled conditions of temperature and humidity. Aging allows naturally occurring enzymes within the meat to slowly break down some of the connective tissues that contribute to toughness. The muscle of beef undergoes progressive changes after slaughter that affect the tenderness of the cooked product.

First, muscle goes into rigor, a shortening and stiffening process. Rigor generally lasts from a few hours up to one or two days. During this period, the meat will be least tender if cooked. After the rigor process, muscle undergoes changes that result in a gradual improvement in tenderness.

While muscle is undergoing changes associated with tenderness, chemical breakdown of certain muscle and fat constituents occurs, resulting in a more intense flavour and aroma. In general, these changes in flavour and aroma are desirable to most consumers. However, undesirable flavours and aromas can develop during aging due mainly to the effects of microbial growth, rancidity of the fat and absorption of off-odours if present in the chill room.
(Source: University of Missouri-Columbia: Hedrick, Stringer, Clarke)

Cooked, un-aged beef has sometimes been described as "metallic" and lacking in typical beef flavour. True beef flavour is fully developed after about 11 days of aging. To a lesser degree, the aged beef flavour increases with additional aging time.
(Source: University of Minnesota, Richard J. Epley)

Beef aging will reduce muscle weight through moisture loss. Because lean muscle is approximately 70% water, dehydration occurs over time though the decreased yield varies depending upon temperature, humidity and air flow. For example, beef that is wet aged may undergo as little as 1-2% loss while dry aged beef may reach a weight decrease of 15% to 20%.

It is important to realize that theories on the effects of aging vary widely across the industry. There are those who insist that only 4-16 days is required, while others stand by a minimum of 28 days. The results of aging continue to be subjective and rely heavily on personal preferences. Stronger flavours can be achieved through a longer aging period or by dry aging. However, it is generally accepted that aging is a critical factor in quality beef, in terms of both tenderness and flavour.

Dry vs. Wet Aging

Dry aging is the process of aging beef carcasses, known as "swinging beef", in open air, under refrigeration and with rapid air movement. The temperature needs to stay between 36°F and freezing. Too warm and the meat will spoil; too cold and it will freeze, stopping the aging process. This practice in North America is very rare because of the costs associated with moisture loss and concerns about food safety. There was a time when all beef was aged in this manner but those days have long since passed.

The majority of beef shipped to foodservice distributors by the packer is boxed. That is to say that the primal cuts are pre-packaged and vacuum sealed at the packing plant. Distributors, and some foodservice operators, will then store the boxes for aging as prescribed by the specification. This is referred to as wet aging. Aging of beef is practised to varying degrees in the industry and it is not recommended for foodservice operators to age their own beef, unless the conditions are tightly controlled. The ideal aging conditions, including temperature, humidity, space, and close monitoring, are required for an effective and safe aging program. Unless beef is the house specialty, aging is best left to the distributor.

There is considerable debate as to which process results in the most desirable flavour. Most people agree that dry aging results in a unique flavour but those not familiar with dry aged beef often describe it as slightly "musty" in flavour. For connoisseurs, dry aging results in a more intense beef flavour compared with wet aging. In studies, overall eating satisfaction was higher in cooked steaks that were wet aged because of fewer off-odours and off-flavours.
(Source: University of Minnesota, Richard J. Epley)

Location of Cut

Within any beef cut, there is a considerable variation in tenderness among muscles. For example, tenderloin is much more tender than the fore shank or heel of round. This difference is due in part to the amount of connective tissue in the various cuts. The tenderloin has a small amount of connective tissue in comparison to the fore shank or heel of round. The amount of connective tissue present is due to the function of the muscles in the live animal. For example, the fore shank and heel of round are used quite heavily in locomotion (movement) and, therefore, have relatively large amounts of connective tissue. Conversely, the tenderloin provides a support function in the animal and, therefore, has less connective tissue.

Another source of muscle-to-muscle variation in tenderness is the amount of stretch or tension applied to each muscle while the carcass is being chilled. This stretching is due to the weight of the carcass and prevents shortening (contraction) of the muscle, which, in turn, results in more tender meat. The major muscles in the rib and the loin are stretched more during the chilling process than are the major muscles in the chuck. Therefore, cuts from the rib and loin are more tender than cuts from the hip and chuck. This is the major reason why the tenderloin is the most tender muscle in the beef carcass.
(Source: University of Minnesota, Richard J. Epley.)

Trim Specifications

Finally, how beef is trimmed and further processed will directly affect the tenderness on most cuts. Understanding the correct trimming and portioning methods for various muscles will contribute to the increased palatability of the cooked product.

Meat grain direction, fat content, exterior fat coverage and amount of connective tissue must be handled correctly to get the optimum results from each cut, and some muscles are easier than others to portion. For example, portioning the striploin into New York steaks is relatively simple as compared to some of the chuck cuts.

When portioning in-house, having the right knife skills is as important as buying the right quality. For example, not removing the backstrap from the striploin prior to portioning will produce a very undesirable steak. Knowing the grain direction of the muscle being portioned and cutting against the grain is critical to maximizing tenderness. The example below illustrates the grain direction on the flank and the correct cutting direction.

Beyond the tenderness benefits of properly cut beef, one must also consider cost and yield. There is a cost in terms of labour and equipment to portion beef in-house. Also, ineffective use of trim and improper cutting will result in very poor yield from the muscle. Yield analysis is reviewed in greater detail in the Beef on the Menu section.

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