Keeping tea in the freezer

I was advised by a Japanese vendor (very good one) that it would be okay to freeze Japanese greens; however, I am sure that the radical drop in temperature will affect the theaflavins and chlorophyll levels. Residual moisture and humidity, I would surmise, would also affect the delicate nature of flavours and aromas. Frankly, I think it would ruin a good pu-erh. In other words, I wouldn't do it. Shen

I think the general wisdom is that keeping your unopened, sealed bags of tea in a refrigerator is the best way to store them. However, there are a couple things to be aware of.

Make sure you let your tea return to room temp. before opening the bag for the first time, otherwise atmospheric water vapor may condense on the leaves, which can cause problems with storage.

Also, don't return an open bag to the refrigerator, unless you are

*certain* it is airtight (which is difficult unless you have equipment designed specifically for the task). You will likely pick up odors and moisture if you put an open bag back into the fridge.

I imagine storing tea in a freezer is even riskier than storing it in a refrigerator, and you have the added danger of freezer burn.

-Brent

green tea ,pressurized it .

Many Chinese vendors, especially those peddling TGY, keep their teas in a freezer or some kind of cooling unit. I have asked numerous times about what kind of fridge they use and I usually get a response like, "any fridge will do as long as there is no strong smell that could get into the tea". I tried this with a low quality fridge on some excellent TGY in 05, when I still drank TGY, and it left a freon smell in the leaves even though I had put 2 or 3 plastic bags around the little baggies the tea was in.

I say, do it at your own risk. With greens and "qing" tea (TGY), it could be ok, just make sure your fridge is up to snuff.

Cooling alone will have no adverse effect on the chemical constituents of tea - or much of anything else, for that matter, except perhaps metallic tin.

IMO, chilling is a great idea for expensive and fragile green teas. (I also do it with some oolongs.) Aside from the obvious issue of aroma uptake from stuff in the fridge, the biggest issue is probably moisture management, in two senses:

- Condensation onto cold tea when opened. Solution here is simple: don't open the bag until it reaches room temperature.

- Condensation within the bag. This is very common and not easy to avoid. As the bag cools, the outside is colder than the bulk tea. Moisture moves rapidly, even at very low temperatures - why snow disappears even at forty below. The immediate result is ice crystals around the edges of the bag. No problem, until it melts, and soaks the tea.

Probably the best way to handle the latter issue is to keep the tea as dry as possible (e.g., using desiccant bags) and refrigerate instead of freezing. This will slow some key staling reactions dramatically, perhaps enough for a year. (BTW, another desiccant sometimes used by chemists is ordinary cotton, baked very dry in the oven.)

If you want to get fancy, flushing the tea with dry nitrogen before chilling will remove some moisture and most of the oxygen, thus eliminating many adverse chemical reactions. Mike Petro's Pu-erh.net site has a handy description of how to do this.

-DM

Make sure they are hermetically sealed. Nothing gets in, nothing gets out. Don't take them out till ready to use. Don't refreeze. I think a better solution than hot humidity storage over the long haul. Make sure freezer is frost free. I would also use additional freezer wrap to make sure. Blanched vegetables hold up forever in a freezer. You can consider green teas in particular as blanched. Freezing versus zero is just a function of utility bills.

Jim

Gyorgy Sajo wrote:

Hey all

Excellent tips all round. Just to add my cents with some tips gleamed directly from Nigel (teacraft.com) from his earlier posts:

Generally it is advisable to seal your tea into useable chunks - so your 50 grams are fine. If you drink your green infrequently, try to pack them into smaller bags.

Some specific answers to your fridge versus freezer dilemma:

1. It's best to use freezer than fridge. The lower the temperature, the slower the degradation. Industrial freezing is uses minus 18 degrees.

1. Chest freezer is better than stand up version as cold air stays below.

2. If left in fridge or freezer, minimize the number of times it is opened to keep the temperature constant. So a freezer might be preferable as it's opened less frequently.

1. Condensation within the packet is a problem with freezer (your sealed packet might contain small amount of moisture that crystallise at below freezing point). It depends on how good your packers are.

My experience with 50 grams (that has been freezed at minus 5 degrees) is that they keep well.

1. Do not re-freeze after you open you packets. Keep the opened packet in a small air tight container in a cool cupboard or something.

Hope it helps:)

Julian

Thanks for everyone for the very helpful answers. My greatest concern was whether the vital chemical components of the tea - vitamins, clorophyll, theaflavins - will be negatively affected, but according to DogMa there is no risk for that.

Interestingly I have not yet had problems with condensation, not even with the already opened packs that I frequently - once or twice a day - take out from the freezer. Maybe during the few minutes while they are at room temperature they do not have the time to collect condense water.

Thanks again, Gyorgy

Gyorgy

If your tea tastes good, then chances are that its nutrients are kept intact.

Key nutrients of green tea such as theanine, catechins are easily oxidised away by moistures. They also contribute greatly to tea flavors. If the tea continues to taste great, chances are other nutrients such as vitamin C has not yet been corrupted by moisture.

For some green such as longjing, the leaves should be so dry that if you rub it with your fingers the leaves simply turn into powder.

I am glad we help to put your mind at ease.

:)

Julian

Possibly, especially if it's very dry where you are. If there's no visible condensation on the packaging, you're probably OK. But condensation won't be visible on the leaf until it's soaking wet. Long before that, there will be enough extra moisture in the tea to cause frost problems. Again, I think the issue is mainly formation of liquid water when frost forms and thaws, which both starts cold-brewing the tea and also ruptures cell walls. I believe that tea is supposed to be packed at around 6% moisture, and could probably be more than 50% wet without looking any different.

Since cooling and re-warming shouldn't affect the tea, it would be safer to let the container warm to room temperature before opening.

-DM