Beef that has begun to turn a grey color, has dried out edges, and does not smell fresh (slightly pungent and sour smell), should not be purchased. Beef that has a slimy feel should be avoided. Excess liquid may indicate that the beef is old or has been stored at the incorrect temperature. It may also indicate that the meat has been previously frozen. Beef that has little excess liquid in the package is the best to purchase.
Fresh beef has a bright red colour when aged up to about 3 weeks in vacuum packaging and at a temperature between 0°C and 1°C. Beef of this age is suitable for stewing, braising and boiling.
Beef for grilling, roasting, pan-frying and sous-vide cooking should be aged more than 3 weeks in vacuum bags at a temperature between 0°C to 1°C. This results in slightly darker meat because of the absence of oxygen in the vacuum bags. However, the meat should still look appealing with no spots of discoloration or drying.
Beef in the vacuum bag has a bluish-red colour due to the lack of oxygen. However, its colour will change to a brighter shade of red once the vacuum bag has been opened and air has had a chance to circulate around it. The meat may have a slight smell when it just came out of the vacuum bag. This smell, called the “confinement smell”, is again due to the lack of oxygen in the vacuum bag. After drying the meat with a kitchen cloth, the beef will breathe and the smell will disappear.
The fat colour of grass-fed beef may be yellowish due to the pigment “carotene” which is contained in the grass. Grain-fed and corn-fed beef produces a whiter fat colour (pictured below).
Marbling (pictured below) refers to small strands of fat distributed throughout a cut of meat and is highly desirable in beef cuts. The intramuscular fat tend to melt during cooking, which adds flavor and juice to the beef and tenderises it as it cooks. Marbling fat is higher in monounsaturated fat which is not harmful for you. Grain-fed and corn-fed beef can be characterized by the higher levels of marbling than grass-fed beef. The longer the cattle are fed on grain or corn, the more marbling the meat has (this reaches a peak depending on the individual cattle) and the more expensive it is.
Lean beef tends to be tougher after cooking because of the lack of marbling. Lean beef may be lower in fat and calories, but it lacks the tenderness and flavour of well marbled beef cuts.
