Factors Affecting Grassfed Beef Flavor



Grassfed beef is often criticized for its unusual flavor. And yet some grassfed steaks take center stage at high-end restaurants. What makes the difference?

Factors Affecting Grassfed Beef Flavor

Factors Affecting Grassfed Beef Flavor

Grassfed beef is often criticized for its toughness and unusual flavor. And yet some grassfed steaks take center stage at high-end restaurants, where they receive rave reviews. What makes the difference?

Before launching into a technical discussion of the many factors at play, it is important to first recognize a key fact about beef flavor. This is that the flavor is stored in the fat. The lean muscle protein itself has little flavor.

With this in mind, what makes the fat cells taste pleasant or unpleasant?

Age & Gender

Studies suggest that steers and heifers taste more or less alike. On the other hand, a mature bull has a stronger flavor suitable primarily for processed meats such as baloney.

Beef flavor increases with age. It is difficult to achieve a good flavor from young animals. They are frequently slaughtered while still too lean, resulting in gamey tastes. When adequately fattened, they typically have very little flavor at all.

Grassfed beef steers often taste the best when slaughtered at three to four years of age. In France, it is common to harvest female beeves as late as five years of age.


While breed is not the most important factor in grassfed beef flavor, it does play a role. Some breeds are better adapted to low-input, forage-based systems than others. Because these breeds are less likely to experience stress in the normal course of grass-finishing, they have a distinct advantage over their large, fast-growing counterparts.

Likewise, within any given breed are usually bloodlines ideally suited for a grassfed beef program and others that have been developed to thrive with more inputs. Grass finishers will achieve the best results by selecting cattle bred for their intended purpose.

Furthermore, a full-bodied beef flavor depends on a healthy endocrine system, which appears to be at least partly genetic.

Soil Quality

Soils with an imbalanced pH can adversely affect forage quality and therefore beef flavor. For example, acidic soil (a pH below 5.6, in this case) can result in excess iron in the animal’s system, causing muscle weakness. These weak-celled muscles can leak excess iron into the surrounding fluids immediately after slaughter, resulting in an unpleasant metallic taste.

But soil pH can impart other unpleasant flavors, as well. As a general rule of thumb, acidic soil makes beef taste sour, or perhaps “swampy.”

Forage Type & Quality

While genetics are important, forage quality has a more pronounced and immediate effect on beef flavor. For example, grazing endophyte-infected fescue can cause an egregious “off” taste.

Any type of forage that does not produce an average daily gain (ADG) of 1.67 pounds or better can cause poor flavor. A gamey taste is the most common complaint, but a metallic or algae-like flavor is also possible.

Excessively mature forage can cause a metallic taste.

A grassy taste suggests forage that contained too much protein and not enough carbohydrate. While this can occur naturally, the situation is typically exacerbated by the use of nitrogen fertilizer, which tends to raise the protein level of the grass. On the other hand, a balanced forage, such as annual ryegrass, is perfect for grass finishing and consistently produces quality beef.

Grass high in calcium and phosphorous, on the other hand, produces a sweet, pleasant flavor.

Cattle that are forced to consume too many broadleaf weeds and shrubs can develop a fishy or swampy taste. This problem can be corrected in some cases by easing up the grazing management to allow for more selective grazing. In most cases, however, the situation arises during a drought; selling off part of the herd may be necessary.

Additional Feeding & Supplementation

Silage is frequently a culprit in grassfed beef with poor flavor, commonly imparting a metallic taste. Typically, the higher the moisture content of the silage (over 30%), the worse the flavor of the beef. That said, some degree of sour flavor can be expected with even quality silage due to its low pH.

Dry hay, however, is not the ideal cattle feed, either. Green grass is necessary to ensure that the meat contains the fatty acids that will give it a memorable flavor.

Grain feeding usually results in bland beef, which can be either desirable or undesirable depending on your taste. The type of grain fed makes a difference, as well. Corn is associated with the average beef sold in American grocery stores, while barley may impart a slightly stronger flavor.

Intramuscular Fat

Intramuscular fat, also known as marbling, is, as previously mentioned, where the flavor in beef is stored. Therefore, it stands to reason that tasty beef will have a moderate amount of fat, not too much and not too little.

Unfortunately, the USDA grading system, based on marbling, tends to reward excessively fatty beef. USDA Choice beef is about 4% fat. USDA High Select at about 2% fat is a lower grade, but studies suggest that the beef may actually have a better flavor.

At the other end of the spectrum, excessively lean beef can taste gamey, fishy, or something like liver. Usually, this unusually low fat level results from harvesting the animal at too young of an age.

Marbling is somewhat influenced by genetics, although the Angus is not the only breed capable of marbling. But more important than genetics is nutrition and health from birth to one year of age. No matter how much nutrition is provided to a steer at finishing time, it cannot compensate for a deficiency or severe illness during the first year of life. For this reason, calving at peak forage production time will produce better beef.


Stress immediately prior to slaughter causes adrenaline release, which will give the beef a metallic taste.


Aging is usually practiced to improve the tenderness of grassfed beef. Aging up to about seven days has fairly little effect on the flavor. After that period of time, fat-soluble compounds are released that can significantly alter the flavor of the beef.

The risk with long periods of aging is that any existing off flavors in the beef will be amplified. In particular, a sour taste associated with acidic soils will grow markedly worse. Likewise, extra-lean beef will develop an overpowering flavor, as the flavor compounds are released much faster in leaner beef.

For these reasons, grass-finishing experts advise against aging grassfed animals for more than 10 days.


Any beef can acquire an unpleasant freezer-burned taste if improperly stored due to oxidization of the fat cells. For best results, store beef between 0 and -10 degree Fahrenheit, and consider vacuum-packing a portion of a bulk beef purchase if you plan to make it last a year.

Personal Preference

Ultimately one of the most powerful factors in determining whether meat will be well received or not is the consumer’s own preference. Many Americans are accustomed to bland, relatively flavorless beef because that is what is largely available in grocery stores. Anything with any type of flavor may be deemed unpleasant.

Smell accounts for roughly 90% of beef taste. Beef that smells delicious will likely taste delicious to most people. Those with a less sensitive sense of smell could possibly be those who prefer a steak with a stronger flavor. Likewise, older people usually prefer a stronger flavor than younger people.

But in the end, what the customer is used to eating is often the most important criteria in determining his flavor preferences.


Nation, Allan. “Allan’s Observations.” The Stockman Grass Farmer. October 2010.

———. “Allan’s Observations.” The Stockman Grass Farmer. October 2012.

Pordomingo, Anibal. “Consumer Taste Study Produces Lots of Surprises About the Degree of Fatness Needed for Quality Beef.” The Stockman Grass Farmer. October 2010.

———. “Soil Acidity Affects Grazing Animals’ Health, Rate of Gain, and Meat Flavor.” The Stockman Grass Farmer. August 2013.

Walters, Charles, and Gearld Fry. Reproduction & Animal Health: How to Select, Breed, and Manage a Herd for Health and Performance on Grass. Austin: Acres U.S.A., 2003.