Our Oolong tea extract (OTE) is naturally dark because after picking, tea leaves are fermented and oxidized for several weeks (without being exposed to excessive humidity and oxygen). It has a very long and sometimes unlimited shelf life. When stored correctly, OTE can continue to age naturally and enhances its contrasting power in microscopy. It is the OTE tannin that we use because it itself is a very good preservative. On the other hand, the aqueous solution of OTE can only be kept for a few hours (so prepare it just before use).
*Trick :
The preservation of the properties of Oolong Tea extracts (OTE) is prolonged when OTE is stored correctly. To do this, you should not open the storage container often. Each time it is opened, it comes into contact with humid air, which reduces its contrasting power. Therefore, it is important to divide Oolong Tea Extract (OTE) and store it in several portions in a cool place.
réf. produit # GP18-10