Cork Resting and Processing - Part 5 in Winemaker Andy Schweigers' Portugal Journey

After our morning in the forest, we followed (well not literally) the cork road an hour north to M.A. Silva 3; the yard and processing plant which is the next step on a corks’ journey. While most companies allow the cork to sit on the forest floor for an indeterminate amount of time, Silva brings it to this facility on the day it is harvested.

Trucks loaded down with cork are unloaded and restacked by hand.  Pieces that have burls, knots, are very misshapen, or that are otherwise unsuitable for cork may be sorted out at this time. Samples are taken for the lab for a second glance at TCA levels in the bark material. The piles are all numbered. These numbers will follow the cork all the way through to finished product. Now begins the rest. At harvest, moisture is spread unevenly throughout the slabs…some are drier than others, some have dry spots.  These slabs of cork will be allowed to rest on the concrete slabs from 6 months to a year. Samples will be drawn periodically to determine if the moisture level is consistent throughout each individual slab as well as that stack as a whole.

After it has been determined that the cork is ready to be moved on, the cork is stacked onto large stainless steel racks. The racks are then lowered into a steamer. Chlorine free water is brought to a boil and these slabs “cook” under pressure and steam for about twenty minutes. When it is done, the cork is much more sanitary and has flattened out substantially, making it much easier to handle. The steamers are powered by burning cork pieces that are recovered later in the processing. From here, the slabs are brought inside for some preliminary sorting.

Next to the steam vats is a large warehouse, almost the size of a Costco. In here are about twenty sorting stations. At each one, a man with a very strong dominant arm holds court. Piece by piece, he removes a freshly steamed slab from the pile and cuts a thin slice off of two sides from each piece with a long, thin scythe like knife. In that instant, he evaluates the porosity of the cork and sorts it in to one of several different piles based upon grade. Now, I’ve always been a hands on kind of guy…so in my broken Portuguese, I asked one of the men if I could try, he smiled and handed the knife over. Anxious to try a new opportunity, yet also not wanting to hospitalize myself, I gave a tentative pull. It was a lot harder than it looked. My new friend smiled, adjusted my stance and how I was pulling. It became EVER so slightly easier.

As the sorted piles grow, they get palletized, labeled, and loaded on to trucks…from here, it’s a three hour drive north to Porto which it was time for our busload of winemakers to do as well.

There are two important things that happen in this sort. First of all, they are getting a pre-sort on the quality of the bark. Secondly, there is now a very smooth surface on two sides of the cork…but that wouldn’t become evident until the next day, when we got to see the cork being punched…