When I first explained to Jerry (age 15 at the time) and Megan (age 12) that I was going to observe sorting while in Portugal, I’m very certain they visualized something much like this:
While cork sorting may not be that “magical”, the combination of science and hard work make the process seem even more magic than anything Hogwarts could ever dream up.
Even though the cork slabs were presorted before punching, there can now be some variability within a given lot of cork. All the freshly polished corks now go through one of several optical sorting machines that M.A. Silva has at this facility. This machine very rapidly takes a photo of both ends of every cork as long as a panorama of the barrel of the cork. A computer program measures the amount of “dark space” on a cork which represents a lenticel (or pore) on the cork. The
more dark spaces, the lower the grade. It then ejects that cork into one of several bins, further refining the quality of that lot.
Now that the cork has been sorted into “almost there” lots based on quality, it comes time to wash the cork. The intent is to provide a sanitary wash. This is done in a mild solution of Hydrogen Peroxide. Not only does this eliminate the majority of any potential harmful bacteria, yeast, or mold on the surface of the cork, it also removes the most of the dust from the processing up to this point.
The cork has one more sort before heading out of the factory now. Now is the time for the essential hand sort. While the optical sorter established a targeted quality grade, there is no machine that can compete with the skilled human eye. The entire batch of cork rolls on conveyers in front of highly trained women looking for nicks, mineral stains, and other imperfections in the cork. Each shift starts with, and at periodic breaks, they review, reference samples of what each grade should look like. If a cork doesn’t make the grade, it’s put into one of several bins where it may be reclassified, ground up for alternative cork products, or ground up for fuel for the cork boilers. Corks which pass muster proceed to the end of the conveyor where they are bundled up and, for the purpose of my cork world, shipped off to M.A. Silva, U.S.A.
So, while “my cork” journey is complete…there are more stories to come… I may even share some images from a tour of a facility making “FrankenCork”!