Carbon dioxide

Pu'er tea is most intriguing due to its transformation, from raw to ripe, from new to aged, constantly evolving and painting a rich landscape of the Pu'er world. We often see the results of this transformation easily, such as the change in infusion color to orange-red or the emergence of plum, fruity, and woody aromas. But where do these flavors come from? What changes are occurring within the Pu'er tea? Let’s take a look together. 1 Dry Matter Loss During storage, there are many reasons for dry matter loss in Pu'er tea. Pu'er tea consumes oxygen and releases carbon dioxide; some proteins and amino acids deaminate and release ammonia; pectic substances decompose and release methanol; certain organic acids are oxidized and release carbon dioxide, among other reactions. In the storage process, hydrophilic colloids in Pu'er tea undergo decomposition. The water that was originally bound with the colloidal substances becomes free, leading to a “self-moistening” phenomenon in stored Pu'er tea. As this self-moistening occurs, water-soluble colloidal substances in the tea may undergo hygroscopic dissolution (this is particularly noticeable when storing Pu'er tea with low maturity). All of these factors contribute to dry matter loss. During storage, the amount of dry matter…