The concentration of TCA that can be released from a cork stopper in the bottle and perceived by a taster depends on the type and, above all, on the alcoholic level of the bottled product. Natural corks will be selected and divided into 4 different classes of TCA, which can be totally customized (e.g. corks with TCA < 0.5 ng/L for white and light red wines; TCA < 1.0 ng/L for structured red wines; TCA < 1.5 ng/L for fortified wines; TCA < 2.0 ng/L for spirits). In this way it is possible to rationalize the internal production according to the bottling destination.