1According to one theory, mayonnaise originated in the town of Mahon in Spain.
2Where it was known as salsa mahonesa.
3Mayonnaise makes sandwiches zestier.
4Turns canned tuna into tuna salad.
5Hard-boiled eggs into egg salad.
6And it's a creamy dip for French fries, Belgian style.
7Mayonnaise recipes vary,
8but all have eggs and oil as the main ingredients.
9The eggs can be all yolks, all whites, or a combination of both.
10At this mayonnaise factory, the raw eggs arrive in liquid form by tanker truck.
11They've been pasteurized to kill off salmonella and other common bacteria.
12The egg supplier has also cleaned and sealed the tank valve,
13an additional food safety precaution.
14A worker clamps a sanitary evacuation hose to the tank.
15Then, with a few blows of a mallet, releases the valve.
16A pump draws the eggs through the hose into a refrigerated receiving tank.
17The second main ingredient, soybean oil, arrives by a railway tanker car.
18Like all bulk ingredient deliveries, for food safety, the tank is sealed at the supplier
19to ensure it isn't opened prior to arrival here.
20A pumping system transfers the oil to a large holding tank.
21Meanwhile, factory workers weigh out the ingredients that make up this company's secret blend of spices.
22Next, they mix this spice blend with white vinegar, cider vinegar, and salt.
23Then, they add liquid natural flavors.
24They pour this mixture into a large tank of room-temperature water,
25producing what they call a slurry.
26The raw eggs, meanwhile, have been transferred into a large refrigerated holding tank.
27So now, there are three holding tanks at the ready:
28a slurry tank, an egg tank, and an oil tank.
29A computerized proportioning system extracts the required amount from each tank
30and sends it to a mixing vessel.
31A couple of minutes of mixing at high-agitation merges the eggs, oil, and slurry
32into tangy, creamy mayonnaise.
33The factory draws samples periodically
34and sends them to its quality control department for analysis.
35The lab technicians there evaluate several criteria,
36such as color, consistency, and, of course, flavor.
37In this test, for example, they mix the mayo with phenolphthalein, a pH level indicator,
38and deionized water to check the acidity level.
39Once the mayonnaise passes quality control inspection,
40this rotary filler dispenses it into recyclable polyethylene jars.
41It fills each jar in just a quarter of a second.
42The next machine twists on a plastic cap.
43Inside the cap is a foil seal.
44This machine uses targeted induction heat to fuse the seal to the rim of the jar
45without heating the mayonnaise in the process.
46The seal preserves freshness
47and indicates the jar wasn't tampered with after leaving the factory.
48The labeling machine glues on one end of the label,
49spins the jar to wrap the label around,
50then glues down the other end.
51The quality control lab also performs some post-production spot checks.
52In this test, technicians use a machine called a viscometer
53to measure the product's consistency.
54The factory also packages its mayo into single-serving pouches.
55They're made of polyethylene film on one side, foil printed with the product label on the other.
56This multitasking machine forms rows of pouches,
57inserts about four ounces of mayonnaise per pouch,
58then seals and separates the pouches.
59These pouches are shipped to ready-made sandwich vendors and fast-food restaurants,
60whose customers need mayo on the go.