It has recently become more and more obvious that people just don’t know how to store tea correctly. It’s kept in its box or bag and that’s it – job done. However, there are so many factors that affect whether the tea you will have today is different from the one tomorrow.

Below I have highlighted some of the most common mistakes tea drinkers make, whether it be with loose-leaf or in a tea bag, as well as explaining why and what effect these bad habits can have on your tea.  I also give some simple solutions.

1. Keeping the tea in an attractive glass jar on display.

Storing tea where it may be exposed to sunlight can result in the lightening of the tea leaves. This is because the ultraviolet (UV) light breaks down the chemical components found in the tea leaves, bleaching them of any colour, as well as giving the tea a metallic flavour due to the light-induced damage. The exact reaction initiated by the sunlight is not actually known; however, many theories indicate that a combination of chemical reactions takes place in the chloroplast (site of photosynthesis) and the cytoplasm (site of most cell reactions).

There are numerous ways around this issue, including simply storing the tea in a cupboard rather than on the work surface. Even well-sealed, opaque glass canisters should be stored carefully but will serve better to preserve the life of the tea. Individually sealed tea bags with colourful foil packets are attractive and when kept in a clear glass jar away from direct sunlight can be an effective way to keep the tea relatively fresh.

2. Allowing a tea jar to reach the bottom before refilling.

As the amount of tea, loose-leaf or in a tea bag, decreases in the jar the amount of air inside the jar increases. This can become a problem because over time tea leaves continue to oxidise, despite being slowed due to the heating process all tea undergoes, with exposure to oxygen. With less tea in the container, the deterioration speeds up, whilst when full the process is slowed. As the tea oxidises it will lose a large amount of its flavour before becoming noticeably stale. Impurities, such as dust, and increased moisture content, can cause the tea to develop an unpleasant flavour, due to the exposure to air.

Airtight vessels minimise the amount of air present when full, but some ambient air remains in between the tea leaves – airtight is not the same as air-free. For this reason, when trying to keep your tea fresh maintaining a full container is imperative, whether its tea bags or loose-leaf. Some retailers will vacuum seal airtight, food-grade pouches for the tea; this is an excellent way for it to be bought if it is likely to remain unopened for a long time, and its shelf life can be extended through freezing but only when vacuum packed.

The only exception to this is Pu’er tea, as it needs access to some air in order to properly age. It should, therefore, be stored in a breathable container, such as fabric.

3. Storing the tea above the kitchen stove or hob in a cupboard.

Although they are convenient, cupboards or shelves above a hob or fridge are some of the warmest places in a kitchen. Also, any location in direct sunlight is too warm for tea storage. The oxidation process can be sped up when heat is involved, as the proximity to heat can adversely affect the chemical and physical nature of the tea. This can cause the tea flavour to degrade significantly.

A dark, dry and cool cupboard away from heat is an ideal location for storing tea. However, tea can also be stored in the freezer or fridge in small packets, which will increase the shelf-life due to the reduction in oxidation. It is advisable to separate the tea into small packets that can be used within a week or two before placing them in the freezer/fridge, rather than having one big bag you keep having to open. Before placing in the fridge/freezer remember to squeeze out as much air as possible, as any remaining air will condense and cause problems. However, the most important aspect when storing tea in the fridge or freezer is to allow it to reach room temperature naturally before opening and this will usually take several hours.

Some of the more delicate teas, such as green and yellow, are best when stored in the freezer or fridge.

4. Stowing tea next to your kettle in easy reach

When the tea is exposed to moisture the leaves release their flavour. Whether this is in the form of steam or liquid does not matter. Tea is hygroscopic, which is the ability to draw moisture from the air. Adding moisture to tea leaves can result in a mossy odour and undesirable flavour in the tea. This means you don’t really want to ‘steep’ your tea until you actually mean to ‘steep’ your tea.

In dry climates, moisture getting into tea is not usually a problem; on the other hand, in humid coastal locations, it is important to be vigilant. You should always ensure dry leaves are stored in a cool, dry place in an airtight container, as most good airtight containers are also good moisture barriers. However, if you use tea bags, or loose-tea in a paper canister or simple paper wrapper, a secondary layer of protection is highly recommended if they are to be stored for an extended length of time.

5. Storing tea next to spices

Tea leaves have a particular quality that is extremely beneficial in the production of scented teas, such as jasmine; however, that same quality can also be detrimental. This is the ability to absorb scents from their surroundings so, when stored with your herbs and spices, the tea will end up tasting like the other products on the same shelf, often leading to the tea developing an unpleasant flavour. Storing tea in certain wooden containers, plastic containers, or airtight tins with strong-smelling rubber seals can also lead to a disagreeable aroma and taste evolving in your tea.

The environment and container in which you store your tea must be free from strong scent. Simply checking this yourself is the easiest and most effective way. The tea is probably protected from imposing scents if the container is airtight and moisture-proof. However, it is always advisable to keep any other foods or highly aromatic substances in a separate location to your tea, even when the tea is protected in an airtight and moisture-proof container. If the tea is stored in the fridge, any food odours can be exposed to the tea, but a non-porous container solves most of the problem.

As a quick tip, teas that are less oxidised (greens, yellows and whites) degrade faster than their more oxidised equivalents (oolongs and blacks). Also, tea leaves that are more broken down have a higher surface area in contact with air, so will deteriorate faster.

Don’t forget to have some tea on me.