Storing loose leaf tea can be very simple as long as you follow a few easy recommendations and understand the factors that contribute to the degradation of tea. Ideally, your precious, premium tea will be kept in an airtight container that is completely opaque and made of an odourless material such as metal or glass. If stored in a cool and dry location away from food or other odours and consumed in a reasonable amount of time, you shouldn't notice any significant degradation in quality.
So, are all teas treated equally and what about aging teas?
First, it's important to understand the main agent of degradation and how each tea type is affected. As with many things in life, including our bodies, oxygen and oxidation is a significant factor of degradation so, limiting exposure will ensure a fresher product over time.
Some teas are processed in such a way as to limit the amount of oxidation thus retaining the freshness and vitality of the original leaf and making them rather susceptible to deterioration. Green teas, white teas, yellow teas and perhaps some lightly oxidized oolongs would fall into this category. Teas that are oxidized in a controlled manner during processing, such as heavily oxidized oolongs, black teas and some puer (which also can undergo a controlled fermentation), are therefore less prone to deterioration over time and if stored well, can actually improve with age.
Well aged 13 year old Yiwu Puer
What about aging then and how is it done well?
Let's be clear that there is certainly a right way and a wrong way to store your tea for the purpose of aging and improvement of character. It's a bit of an art, just like aging wine or cigars say...The conditions have to be right. There are two methods for long term storage of tea and they relate to the type being stored.
Airtight Storage is typically used for the long-term storage of oolongs and short term storage of green teas. Although the seal is airtight, there is still some ambient air remaining in the container thus allowing a slow, limited oxidation.
Non-Airtight Storage. The processing of Puer, and other post-fermented teas such as Fu Zhuan with it's 'golden flowers', is often done at lower temperatures in order to retain the oxidative enzymes that, when stored well, can contribute to the ongoing oxidation and fermentation that alters the teas character from young and brash to something more woodsy and reminiscent of old books. An environment free from outside odours and light and with a steady temperature and humidity is required for successful, long-term storage. Clearly, we all need dedicated cellars for our ridiculous tea collections!
What are the agents of deterioration to protect my tender green tea against?
- Oxygen. Tea will continue to oxidize when exposed to air even when stored in an airtight container. Repeated opening of your tea container will introduce fresh air and lead to a stale product. Manufacturers will often flush tins or pouches with nitrogen when filling thus displacing the nasty oxygen. This is great for preserving freshness until the package is opened but very impractical for the average person on a daily basis. There are a number of ways for you to maintain tea freshness at home though. If you order larger amounts of tea, use one container as the main storage and fill another smaller container for daily use. This way the bulk of the tea is not exposed to fresh air everyday. Containers with small pumps that extract the remaining air are readily available in stores and online. Another option is the use of oxygen absorbing packets but these will quickly lose their effectiveness in containers that are opened daily.
- Odours. Tea is very odour absorbent which can be great when trying to infuse it with the scent of flowers but not so great when you store it in the fridge next to the block of stinky Stilton. If storing it in the fridge, make sure to have an airtight container. Avoid cupboards with other food and other musty cupboards. Also, consider using containers made of steel or dark glass as plastic containers often have a subtle odour themselves that contribute unwanted aromas and tastes.
- Heat. Oxidation becomes more rapid with increased heat so cool locations are essential for long-term freshness. Obviously, the coolest place in the house is the fridge or freezer but these locations present their own challenges. As mentioned above, the odours must be guarded against when storing in the fridge. The other consideration is the inherent moisture that will condense on the leaves when the remaining air inside the bag is cooled. If you choose the fridge or freezer, make sure to squeeze out as much air as possible before storing it and let the contents warm to room temperature before opening. Ideally you'll store the bulk of your tea in the freezer and have a small container for daily use.
- Light. Let there be light...except on my tea! Not a lot is understood about the effects of light on tea but changes do occur that are not desired. Best to find some nice shade for your tender tea.
- Moisture. It's well known that moisture will degrade your tender teas (or improve them in the case of puer) but we're concerned about storing delicate teas. Tea will pick up ambient moisture, which not such a problem if you live in the Prairies but definitely something to consider in the Pacific Northwest, so keeping them in a dry room is best. Keeping your bags of tea in a cardboard box that absorbs ambient moisture can be an effective way to minimise exposure to moisture.
I hope this helps you in your quest to keep your tea tasting the best it can. One other thing worth mentioning is to simply buy your teas more frequently and in small enough amounts that you consume it within a month or so and let the tea vendors take care of storage. Or just drink lots of tea!