The process of making a natural wine cork.

After the cork bark is harvested from the cork oak tree, how does it become a wine cork?

After harvesting the cork bark off cork oak trees, the bark is gathered and placed in large piles waiting to be loaded onto trucks and transported to the processing factories. The health of the cork oaks is not effected …. The same tree can be harvested over and over again every nine years.

The bark is cut into strips by a very sharp knife. The thickness of the strips determines the length of the cork stoppers. In the above photo the strips are quite thin …. about half an inch or 12.5mm. This means the stoppers punched from these strips would be ½” or 12.5mm in length, about half the length of a standard wine cork often used on olive bottles or spice bottles.

In this picture the stoppers are being punched from the bark strips by hand, the strips are about 1-1/2” long or 38 mm. These are wine stopper corks. The operator must be very precise. After the corks are all punched out of each strip the leftover strips (those with the holes in them) are called “cork waste”. This name is misleading because in cork there is no waste. These leftover strips are later ground up and turned into cork grain. Cork grain is further processed and turned into other products such as cork floors, walls, insulating materials, bulletin boards, coasters, and much more.

Punching stoppers out of cork strips can also be done by automatic machines such as the one pictured above. This is a safer and quicker process but not as exact as hand punching.

After the cork stoppers are punched out they are sorted into various qualities – usually seven standard qualities - by expert sorters who can quickly and effectively recognize the difference between each cork. Qualities are determined by the number of pores, cracks, or other imperfections.

Here you can see the sorters surrounded by wicker baskets. They pick and choose the corks and throw them into the designated seven different quality baskets without even glancing up. They seldom miss their shots, even those they throw side-handed or over their shoulders!

Following these procedures the corks are washed, branded with company logos, treated with a surface coating to make insertion into and out of bottles easier and smoother, and finally sterilized and packed in hermetically sealed heavy duty poly bags which are not opened until they arrive at the bottling line.