How to choose the best Guayusa? The greener the better?
Guayusa is Guayusa is Guayusa, right? Yes and no. Even among the Guayusa plant species there are a number of factors that can influence the taste and nutrition for the leaf in your cup:
Genetic Variety
The differences are particularly apparent when comparing wild guayusa to the farmed guayusa of the indigenous communities. The farmed Guayusa has been bred for 1000s of years for the benefit of consumption. The caffeine levels are lower (3% compared to 8%) – evidently the people found it too harsh and preferred a mellower drink. Among farmed Guayusa varieties there will be differences too depending on how the tribes of different regions have bred them.
Seasonal changes in the rainforest
Because the Guayusa is not grown in a controlled environment, it is subject to the changes in the rainforest, such as rainfall and temperature. These changes can cause variability in its nutrition levels; including caffeine levels.
Time taken to dry the Guayusa
Depending on the time it takes from harvesting to drying, the extent to which it is dried (temperature, length of time). This part of the process can determine whether the Guayusa is bright green, or even black. If the leaves are greener, it means less oxidation has occurred. Oxidation isn’t necessarily a bad thing. In the process of oxidation, catechins (which are bitter) are converted to theaflavins and thearubigins (which contain astringency without the bitterness). Theaflavins in particular are associated with ‘richness’ of flavour, and astringency is a desirable characteristic of a good tea*1.
Some of the nutrition however degrades during oxidation, such as the amino-acids – which is why health nuts may opt for a greener guayusa.
The farming method
Most Guayusa is grown in the shade of the rainforest at the moment (using a chakra agroforestry system). However, with its popularity growing, it is possible some companies will try to improve their yield using monoculture farming methods. Not only would this be bad for the local environment, but depending on the way they do it, it could decrease the quality of the Guayusa. Being shade grown has nutritional and flavour advantages, such as increased caffeine levels, more amino-acids and reduced bitterness of the leaves.
Storage from plant to cup
How the Guayusa is stored, and how long it takes, on its journey from tree to teacup is vitally important too. For maximum freshness (and minimum oxidation) it must be packed and stored in a cool and dry environment away from light. Once stored, an airtight packaging will help keep it at its best for longer.
If you are storing green Guayusa, and the purpose is to keep it as green as possible, you will want to keep it as cool as possible without reaching 0 Celcius, since below freezing temperatures could damage the structure of the leaves. The low temperatures would slow down any further oxidation.
If it is acceptable for the leaf to oxidise a little and mature in taste, room temperature is fine (21 celcius). Bearing in mind, keeping tea in cold storage may keep the leaves fresh for longer, but refridgeration is a very costly in terms of energy and the environment. Ideally a company dealing with large quantities of Guayusa would have a storage solution that prioritizes thermal efficiency; a naturally cool place; for example underground.
At our new facility in Manchester where we store and pack our bulk guayusa, we haven’t managed to create an underground storage, but we have created an insulated cool room with some refrigerating where it ranges between 14 and never exceeds 17 Celsius. The temperature seems a good balance between extending the quality and life of our Guayusa for customers, and not excessively using energy to keep it cool (since the cost and energy usage of keeping a room close to 0 degrees Celsius goes up dramatically).
Our two varieties (Original and Extra Green)
We sell two varieties to leave the decision to you. We find the Original richer, mellower and less bitter and the extra green version to be more bitter, and not so rich. Although it has more grassy and fresh flavours, and more nutrition retained due to less oxidation.
We would love to know your own opinion. As of writing this article our most recent batch of ‘original’ guayusa has turned out to be richer and smoother than ever before with a deep green colour, I urge you to give it a try!
And for your information, our teabags are all made using the same ‘original’ guayusa.
References:
1* https://redblossomtea.com/blogs/red-blossom-blog/how-oxidation-changes-tea-flavor
