There isn't just one way to dry guayusa leaves to preserve them. Among other things, they can be dried directly in the sun, with warm air or in special ovens - we have chosen this method.
The criteria that led us to this method were mainly the taste, the caffeine content and the reproducibility of the results.
Green guayusa is milder. The Ecuadorian sun is very powerful and can reliably dry the leaves, although this may take a few days. During this time, the leaves oxidize in the air. This makes them darker and their taste somewhat more intense or bitter. The brewed tea is also darker in color, while Green Processed Guayusa conjures up a bright green drink.
Green Processed Guayusa tastes fresher and juicier for us in comparison.
The oxidation also has a decisive influence on the next point.
2. Caffeine content
The longer the drying process takes, the more caffeine is broken down. This was found out as part of a study by the "Universidad Nacional de Colombia". While sun-dried guayusa has a caffeine content of approx. 2.98% (of dry matter), hot air-dried guayusa has 3.02%. Leaves that have been dried in convection ovens, such as our Guayusa, come in at 3.71% caffeine content.
Guayusa is a natural product. Each leaf is unique and exposed to the influences of the Amazon until it is hand-picked from the bush. We cannot and do not want to change anything about this fact. However, what we can influence is the further processing. If this is basically the same every time, then the result will taste very similar in the end. Reproducibility is essential not only for the taste, but also for the shelf life, because: only if the right degree of residual moisture is present (we are aiming for 8%), the guayusa is durable and there is no risk of mold or rapid deterioration in quality after the bottling.