Are there detrimental health effects to drinking old tea?

Question

I've come upon a box of teabags which is kind of old - it says "Best Used before June 6th 2014" - so maybe 4 or 5 years old. The ingredient list only says "black tea leaves", nothing else. It was sitting on some cabinet shelf and is still half-full.

Does old tea "go bad"? Is there an actual problem drinking it?

Answer 1

Black tea can last almost forever. Health related detriments are potentially present already in fresh leaves. Risks added by storing tea for too long are first and foremost: taste deterioration. This is especially true if it was stored improperly, that is with spices and other material that emits odours that are then captured by the tea. That is of course all moot if it was stored somewhere moist. Molds growing on it should be of some concern. Since it is black tea that will be prepared with boiling water :this will kill most of the microorganisms present on the leaves, since they never had a chance to thrive on dry material.

Trust your eyes, your nose and your taste buds.
If you think it looks gross now, or tastes way off, don't drink it. Otherwise don't worry.

How long does tea last?:

How long does packaged tea last? Unopened, packaged tea can last a year beyond any "best by" date stamped on the package. Does tea expire? Tea will eventually lose flavor, but dry leaves will last a very long time. The shelf life of tea depends on a variety of factors, such as the best before date, the preparation method and how it was stored.

The Shelf Life of Black Tea:

Black tea is fully fermented, and it has a longer shelf life than green tea. Generally, the shelf life of black tea in bulk is about 18 months, while bagged tea is 24 months. Tins or aluminum foil bags for black tea can be stored for about 3 years, and paper bag is for 2 years.

Food Storage - How Long Can You Keep... Tea Bags, Commercially Packaged — Unopened Or Opened

• How long do tea bags last? The precise answer depends to a large extent on storage conditions — to maximize the shelf life of tea bags (including black, green, herbal and oolong), store in a cool, dark cupboard, away from direct heat or sunlight.

• How long do tea bags last at room temperature? Properly stored, tea bags will generally stay at best quality for about 18 to 24 months. To maximize the shelf life of tea bags, and to better retain flavor and potency, store in airtight containers.

• Are tea bags safe to use after the "expiration" date on the package? Yes, provided they are properly stored and the package is undamaged — commercially packaged tea bags will typically carry a "Best By," "Best if Used By," "Best Before," or "Best When Used By" date but this is not a safety date, it is the manufacturer's estimate of how long the tea bags will remain at peak quality.

• Do tea bags ever spoil? No, commercially packaged tea bags do not spoil, but will start to lose potency and flavor over time — the storage time shown is for best quality only.

• Should you store tea bags in the refrigerator or freezer? Storing tea bags in the fridge or freezer is not recommended, since condensation can result, which will harm the taste and flavor of the tea.

• How can you tell if tea bags are still good? To test whether tea bags are still good, brew a cup of tea for at least 3 to 5 minutes - if the aroma is weak and the flavor is not obvious, the tea bags should be replaced.

Does tea lose its health benefits if it’s been stored a long time? And is it better to use loose tea or tea bags?

While fresh may be best for enjoying many types of teas, that’s not always the case. Some pu’er teas from China are considered to improve in taste with storage, much like a fine wine. In fact, the degradation and oxidation of catechins during storage of pu’er teas result in the formation of new phytochemicals, which have come to be highly valued by tea drinkers for their rich, earthy taste and probiotic health properties.

Related on Cooking.SE (Seasoned Advice): My tea bags are expired, can I still use them?