Beginning at the level of a single wheat seed, the steps to commercial bread baking are copious. Bread is made of three basic ingredients, grain, water and baker’s yeast. Basic production steps include wheat seed development, planting, and harvesting, grain milling and bread manufacturing. Manufacturing includes the baking process of dough mixing, fermentation, dividing, panning, molding, proofing, baking, cooling and depanning (1,2).The process of bread making doesn’t end at the oven, bread must be sliced, packaged, stored, and distributed before we ever see it on our table. From the agricultural and mechanical engineer, to the refrigeration and automotive engineer, numerous engineers help design equipment at each of these levels .(7)
From the seed to the slice of bread in your PB&J, engineers improve the process. Bio- engineers work to improve yield, quality, stress tolerance and pest resilience of the grain.(2,3,4,5) At the farming level agricultural engineers improve all aspects from planting and irrigation to tillage, sowing, and threshing. It is a marvel to see the current farming equipment engineers have developed to harvest wheat. How far we have come from the laborer of old once required to thresh and gather the wheat by hand now replaced by combines that have grain headers that are 35 feet across!(6) The mortar and pestle used in the earliest centuries to grind the wheat to a usable flour is now milled by machines at a rate of 2 acres of wheat per minute (7). Engineers improve wheat kernel and germ distribution, flour manufacturing, and their final contributions are seen at the commercial bakery where the flour is then turned into bread.
Any baker will attest, including your mom in her kitchen at home, the trickiest part of the entire bread making process is dough production. Unlike other commercially produced foods, bread is made “alive” by yeast, a living organism, incorporated in the process. The yeast is combined with a very inconsistent ingredient, flour. Flour quality varies in several different parameters and so does the moisture content of the environment in which the dough is made (air humidity in the kitchen which varies due to differences in altitude and region.) It is easy to see why bakers are lauded for their expertise in working with these variables and coming up with a consistently good end product. This is where mechanical and electrical engineers truly are making continued advances. Quality in the consistency of the flour itself has developed exponentially over the last 10 years thanks to the analytical solutions engineers have develop to minimize inconsistency in moisture, protein, ash, gluten, and water absorption during the milling process. (8,9)
The primary piece of engineered equipment used in this analysis provides a spectrographic assessment of the milled grain. Originally analysis was done by large non-moveable machines housed in off-site laboratories. Engineers brought the lab to the bakery. Ten years ago small flour samples needed to be removed from milling vats, taken to the laboratory and analyzed. The process was slow, only a small percentage of the product was being analyzed, adjustments were made with less accuracy and quality control suffered. Engineers improved this process by developing equipment for on-sight use. Further development of portable on-sight analyzers was a major development, but engineers made even greater advances by developing analytical equipment that could test material in the process stream. Process stream analysis eliminates the necessity for disturbing production by analyzing “mid stream” as flour flows through the milling process piping systems. Engineers had to overcome challenges faced when designing installations points. The milling pipes flow under and extremely high PSI and installing windows used in the analysis that would neither explode nor fail hygiene safety requirements presented problems. But the results have had a big impact on production and quality control. In-line analysis allows for accuracy to be improved as ambient moisture content does not impact results. Frequency of sampling has also dramatically improved (samples can be taken every three minutes vs. every hour). Currently engineers are working to improve the resolution of the analytical equipment. Present technologies employ near infrared-based analysis technology known as High Resolution diode array analysis. Calibration is another area engineers are working on improvement. Portable equipment, being used on several different piping systems within one milling process requires careful attention to calibration (10,11,12)
I was interested to find out how some of these engineering supported improvements to the quality and consistency of the milled grain impacted bakers, so I interviewed in house Bakers from both the Publix and Winn Dixie grocery chains. I asked them how improvements in the quality of baking products impacted them and what they thought engineers could work on to improve the quality and quantity of their bread products. With these smaller scale bakeries much of the dough is shipped from factories premade, but not all. Many of the bread types such as challah, breakfast breads and sliced breads such as Mountain White are made in-store. Older bakers said technology definitely improved the milled product from 20 years ago, but there is a lack of consistency on any single flour type depending on the factory where it is produced. Bakers still need to make adjustments and judge texture by manually palpating the dough. At this level flour analysis technology is not available and monitoring of liquid measuring during mixing and modifying cook time is required of the baker. Bakers at both store chains agreed that it would help them if engineers could design equipment that would further improve the consistency of the flour they receive from factory to factory. I asked if engineers developed small, hand held flour analyzers that could be used on any product regardless of the manufacturer to indicate moisture level, if they would use it. They liked the idea, but expressed that they also enjoy the physical process of baking and too much automation would remove the actual “baking” part of baking bread that they love. They enjoy the creative part of their job and liken themselves to artists. You can’t automate the creative spirit that inspires a baker to continue with his craft. They felt too much automation would lessen the quality of the products as well as employee satisfaction. Although they greatly appreciate the engineering advances that have allowed them to enjoy consistency in the quality of the flour they use, they consider themselves artisans and that is what sets them apart from the large commercial bakeries that rely on machinery to test bread quality.
From the moment you reach for that loaf of Wonder Bread, countless engineers are owed a debt of thanks for its fluffy goodness. Almost every category of engineer has played a part in is production from infant seedling, to bread factory, bread truck, bread store and ultimately to bread basket. It is an exciting prospect to consider what engineering wonders the future may hold, even more exciting to consider is my part in the process.