The first step in making peanut butter is growing the peanuts, of course! All of the peanuts used for peanut butter are grown in the USA, either in the Southeast (Georgia) or the Southwest (Texas and Oklahoma). The two best-tasting varieties for peanut butter are Spanish and Runners (so Safeway used only these two varieties). From the harvest the nuts go to shelling operations. These plants, located near the growing fields, remove the shells, clean the nuts, and pack them into huge bags for shipment to the peanut butter plant. Each bag holds more than 2,000 pounds of peanuts!
At the plant, the bags are unloaded into bucket conveyors that move the nuts from each processing step to the next one. The first step is to insure that all impurities, such as stems and sticks from the peanut plants, are removed from the product stream. This is done by gravity separators, which sort out objects that are heavier or lighter than peanuts.
The peanuts are now ready for roasting. This is done by a continuous roaster. The nuts are slowly carried through the roaster on a belt while hot air is circulated. It is extremely important that the nuts be roasted evenly and properly so that flavor and color are just right. The roaster operator adjusts the roast as required by changing the air temperature, belt speed or peanut layer thickness on the belt.
The peanuts are cooled and conveyed to the blanching machines, which remove the skins. This prevents the peanut butter from having dark specks from the skins.
The last step before the peanuts can be ground into peanut butter is the final inspection for quality. The nuts are conveyed through an electronic color sorter which removes nuts that were under or over roasted. The peanuts also pass a trained inspector who looks them over and picks out any that do not look right.
The peanuts are now ready to be conveyed to the grinders. (If we are making 'chunky' peanut butter, some of the nuts are diverted to a chopper, and are then added back to the peanut butter just before filling the jars.) The grinders are like giant milkshake machines.
Although peanut butter consists of mostly peanuts (at least 90%), small amounts of other ingredients are added while the nuts are being ground. In the case of 'old fashioned' peanut butter, we add a little bit of salt for flavor and a special vegetable oil called a stabilizer. This keeps the peanut oil from separating out to the top of the jar.
At this point the peanut butter is pumped through a metal detector to insure that no metal got into it during the grinding. Then it is pumped into a deaerator, which removes trapped air. Finally, the peanut butter, quite hot from all that grinding, passes through a heat exchanger to cool it down so it can be packed into containers on the filling line.
The filling machine is carefully timed to put the correct amount of peanut butter in each jar. The jar then is conveyed to the capping machine.
Capped jars are sent through an induction sealer, which seals the inner liner to the top of the jar. Then, another machine applies the label to the jar.
The jars are now ready for packing into the shipping case. This is done by hand so that the packer can inspect each jar's label and general appearance.
All that's left is to glue the cases closed and put the peanut butter in the warehouse, then wait a few days before shipping it to the stores. This allows for 'microbiological tests to make sure no molds or bacteria have found their way into the peanut butter. After the tests come back 'clean' we can release it for our customers to enjoy.