This operation consists in freezing the neck of the bottle and uncovering it in vertical position so that the same pressure of the carbonic expels the lees frozen, leaving the cava brilliant and transparent. This process causes a small loss of cava, which is offset adding wine and sugar, which is known as "a liquor of expedition ", that varies according to the type of cava wished. Ours cavas Brut Nature is totally exempt from liquor of expedition because the bottles fill with the same cava.