For today's consumers, bacon is a very different meat product than in our grandparent's day. The fresh pork belly — the raw material for bacon — is a major component of every pig.

Depending on how the carcass is fabricated, bacon accounts for about 11% of the carcass today, compared to 15-18% just two to three decades ago.

Forty years ago, the amount of separable fat in a belly was commonly listed as 68-75%. Today the amount of fat in sliced bacon is dramatically less, 45-55%.

Bacon has gone from a center-of-the-plate breakfast meat item to an integral ingredient in many foods. It is also widely favored as a condiment for sandwiches, particularly in the fast-food/take-out market.

Retail bacon, cooked at home, is still a significant market. Pre-cooked bacon is a growing category at the supermarket and is, by far, the fastest growing and largest segment of the foodservice market.

Beginning in the mid-'90s, fast-food outlets and restaurants have boosted the popularity of bacon by creating new entrees with bacon as a premium-valued flavor and texture addition. This has stimulated phenomenal growth in bacon sales and reversed the once poor profitability of bacon. This surge in popularity has also impacted, in a very exciting way, the entire meat products market for pork.

Throughout the '90s, the number and output volume microwave bacon processing systems has grown markedly. Combining convenience with the outstanding flavor and texture of bacon has made it one of the fastest-growing ingredients in the food field.

Belly Quality Traits

The measure used to assign value to bellies is simple — quality equals weight.

Understanding the unique opportunities and challenges associated with bacon production and processing is multi-faceted. Beginning with the raw material, the pork belly (Figure 1), it is important to focus on how bacon will perform during cooking and how that is related back to the pig, belly, bacon slice, processing and cooking procedures.

Two research initiatives in the Quality Lean Growth Modeling Project (QLGM), a checkoff-funded project of the National Pork Board, focused on the quality relationship of pigs to bacon and the study of production protocols used in making bacon.

Bacon quality, very important in reaching the market growth potential, had not been studied extensively. In particular, the quality measures that could affect some of the new opportunities for sliced, precooked bacon had not been studied.

Cooperation from representatives from the commercial bacon processing industry helped bring testing procedures into better focus. Several new quality attributes that needed further research and evaluation surfaced during this process.

These new quality evaluations included the shrinkage and distortion of a bacon slice during cooking and the color and quantity of the lean and fat. The prevalence of a defect condition seen during cooking, known as “shattering,” was also studied.

Bacon Processing Procedures

Two bacon formulations and procedures, aimed at retail and foodservice, respectively, provided additional quality information in this study.

The retail bacon contained a typical 12% pumping solution and was commercially sliced at 9 slices/in. The foodservice bacon contained the 12% solution with additional sugar and liquid smoke and was commercially sliced 13 slices/in.

Bellies were transferred to a commercial plant for temperature adjustment or tempering, pressing (Figure 2) and slicing. The sliced bacon was returned to the university for testing and evaluation.

Bacon slabs were sampled in five zones following slicing, from the anterior to the posterior end of each slab (Figure 3). Each zone represented 20% of the slices in the slab after incomplete slices were removed from both ends. The first two slices from each zone were used for most evaluations.

Shattering and Composition

Shatter marks were defined as breaks or shatters of the fat portion that occurred perpendicular to the slice. Shatter marks did not include the natural separation of fat tissue or separation between fat and lean tissue (Figure 4).

Shatter marks were classified into five length categories: 1-10 mm, 11-20 mm, 21-30 mm, 31-40 mm, and 41+ mm. Shattering was measured by checking for the number and extent of shatter marks.

The same two slices were then bagged, labeled and frozen for compositional analyses of moisture, fat, protein and ash.

Cooking Yields, Shrinkage

At the same time the first two slices were being taken from each zone for the above evaluation, the next 10 slices were removed from each zone, labeled, packaged and frozen for later cooking analyses. Five slices were analyzed for microwave cooking and five for double-belt cooking.

Of the five slices cooked by either the microwave method or the double-belt cooking systems, three slices were measured for length and width before and after cooking to calculate slice shrinkage. Cooked yields were also calculated on the five slices.

Distortion scores refer to the amount of “wrinkling” in the bacon slice following final cooking. A scale of 1-5 (Figure 5) determined cooked shrinkage for the three slices used.

Establishing Belly Value

To value the belly primal, the weekly prices of each side wholesale cut and trimmings were obtained from the USDA Agricultural Marketing Service and averaged for 2001. The prices reported for wholesale bellies were divided into three groups based on weight — 12-14, 14-16, and 16-18 lb. For this article, the 12-14- and 14-16-lb. weight ranges were used to value the bellies from the example 250- and 290-lb. market hogs, respectively.

The weight and value of the belly primals differed as the size of the hogs got larger (Table 1). The wholesale belly and sparerib weights from the 250-lb. hog were 9.87 and 3.35 lb., respectively. The weight of the belly and spareribs (Figure 6) were multiplied by the 2001 average wholesale prices, which were $0.88/lb. and $1.46/lb. for the 250-lb. hog, respectively, and $0.92/lb. and $1.46/lb. for the 290-lb. hog, respectively.

Table 1. Wholesale Side/Belly Cuts, Byproducts and Value from an Example 250- and 290-lb. Market Hog
Item 250-lb.
Market Hog
290-lb.
Market Hog
Carcass Weight, lb. 183.9 216.1
Backfat, in. 0.95 1.08
Loin Muscle Area, sq. in. 6.05 6.76
Belly Weight, one side, lb. 9.87 12.09
Belly Price, $/lb. 0.88 0.92
Belly Value, one side, $ 8.69 11.12
Belly Fat, one side, lb. 2.03 2.51
Fat Price, $/lb. 0.23 0.23
Fat Value, $ 0.47 0.58
Belly Trim Weight, one side, lb. 1.95 2.47
Trim price, $/lb. 0.22 0.22
Belly Trim Value, one side, $ 0.43 0.54
Total Belly Value, one side, $ 9.59 12.24
Sparerib Weight, one side, lb. 3.35 3.85
Sparerib Price, $/lb. 1.46 1.46
Sparerib Value, one side, $ 4.89 5.62
Sparerib Trim, one side, lb. 2.03 2.38
Trim Value, $/lb. 0.22 0.22
Sparerib Trim Value, one side, $ 0.45 0.52
Total Sparerib Value, one side, $ 5.34 6.14
Total Belly Value, one side, $ 14.93 18.38
Total Carcass Belly Value, $ 29.86 36.76


The 250-lb. hog provided a single belly value of $8.69 and a sparerib value of $4.89. The same two cuts from the 290-lb. hog weighed 12.09 and 3.85 lb., and had a value of $11.12 and $5.62, respectively.

The fat trimmed from the belly primals was 2.03 lb. for the 250-lb. hog and 2.51 lb. for the 290-lb. hog. As with other wholesale cuts, belly fat does have value, as it is sold as edible fat in the wholesale market. This fat can be added to various beef, pork and poultry processed products. The fat from the belly of the 250-lb. hog was worth $0.47, and $0.58 from the 290-pounder.

In addition to the wholesale cuts and fat, the weights of side trimmings from the 250-lb. hog were 3.98 (1.95+2.03 lb. from the belly and spareribs) and 4.85 lb. (2.47+2.38 from the belly and spareribs) for the 290 lb. hog.

The 2001 USDA-reported average wholesale price for 42% trim was $0.22/lb. Hence, the value of side trimmings (belly + sparerib) from the 250- and 290-lb. hogs was $0.88 and $1.06, respectively.

The total value of a single pork side (wholesale cut, fat and trimmings) was $14.93 for the 250-lb. hog and $18.38 for the 290-lb. hog. These values were doubled to $29.86 and $36.76 to determine total carcass belly value from the 250- and 290-lb. hogs.

The total weight of the wholesale side cuts (belly and spareribs) represented 22.0% and 22.2% of total carcass weight from the 250-lb. and 290-lb. hogs, respectively. The belly primals represent 21.4% of the value of the 250-lb hog and 22.5% of the 290-lb hog.

The belly and sparerib markets are similar to other pork wholesale cuts and commodities in that seasonal and/or monthly price variation exists. Monthly averages were calculated from four-year (1998-2001) price information obtained from the USDA Market News Service (Figure 7).

Generally, the sparerib price builds during the spring and peaks by May/June. The lowest sparerib price occurs from October to December.

Monthly belly price is not as variable as that of spareribs. However, belly prices tend to peak during the late summer and decline during fall. This variation is likely due to the supply of pork on the market during these months. The stability of belly prices is supported by consistent consumer demands for bacon. The demand for bacon in the fast-food industry throughout the year no doubt has contributed to seasonal stability of belly prices.

The peak sparerib price months correspond to times when consumers fire up grills and smokers cook ribs during the summer months. However, processors have begun to market a prepared rib product to simplify preparation for consumers. This may lead to less seasonal variation. However, the price variation forces processors to store wholesale cuts like the belly and spareribs to avoid selling all of their supply at any given time, particularly in a low spot market.

Bacon's Bright Future

Much has been learned about bacon in the QLGM project as the data relate to the design parameters of genetic line, sex, diet and slaughter weight. It is clear that there are large differences within the supply of commercially marketed pork. Clearly there are differences due to genetics and sex. The effect of increased market weight was very consistent with our understanding about growth of pigs and the effects of increased fat deposition in the meat.

The treatment of retail and foodservice bacon processing was added to learn more about methods that will capture greater quality. This effort raised additional questions that must be tested under unique commercial conditions.

The expansion of the project to include two processing methods — retail and foodservice — allowed for more than one injection pickle and level of solids. The second expansion of the project permitted two cooking systems to be evaluated — one simulating commercial microwave processing, the other a more traditional retail bacon. This has increased our understanding of bacon cooking performance.

New techniques for evaluation of bacon, including camera visioning for amount of lean and fat and color of the raw and cooked bacon, will be useful for many other products and processes.