How to Make a Kitchen Sized Immersion Chiller to Radiply Chill Tea (for Iced Tea), Stocks, Broths, and Brines

Intro: How to Make a Kitchen Sized Immersion Chiller to Radiply Chill Tea (for Iced Tea), Stocks, Broths, and Brines

tl;dr :)

Confession: I'm a Tea snob (so yeah, I'm not a tea bag guy - loose leaf all the way). Tea is the World's most popular beverage...yet many people are either unaware or intimidated by all the options out there. A quick primer: ALL tea comes from the same plant, Camellia Sinensis, basically picked leaves/buds from new growth. The difference is in how it's processed after it's picked. There are 6 main types (white, green, black, oolong, yellow, and fermented teas like pu-erh). If your picked leaves are quickly dried, you have white tea. If your leaves are withered first to remove some moisture and then dried, you have green tea. If your leaves are crushed and rolled and left to oxidize (imagine if you crumple some Basil or other herb and leave it out...it turns brown - same thing with tea) and then dried - you have black tea. Etc. The stuff you get in tea bags is still tea, but mostly low quality and it may well have been sitting on the store shelf for up to 2 years. Don't buy it unless you know it's good stuff - there is high quality teabag tea out there, but you have to seek it out.

There is fresh, high quality tea easily available online - go get you some and I guarantee you won't go back..

So - when I'm making tea for iced tea, I like to make a large batch (usually a gallon or two at a time), using a fresh and exquisite loose leaf green tea. I make a lot more iced green tea than black tea, but it's really just my preference. Sometimes I'll make an iced black, when the mood strikes...like when a superb first flush Darjeeling comes in :)

The problem is that a large batch (say 1 gallon) of freshly made tea will take ages to cool down sufficiently before you can put it in the fridge. I have the same issue when making stocks and broths, where the problem is exacerbated because leaving those liquids out at room temperature for extended periods while it slowly cools can encourage the growth of bacteria and other nasties. You can ruin your entire batch, or worse you can sicken or kill your entire family - so basically you want to chill your liquid as quickly as possible and refrigerate to keep pathogens at bay.

There are ways to cool large quantities of liquid, but they involve coolers full of ice and are generally a laborious process. What you don't want to do is put a gallon of hot liquid straight in the fridge or freezer, as it will just warm everything else up and still take ages to cool. If it's Winter and freezing out, then no worries - you can just stick it outside to cool...but iced tea is far more popular in Summer so this may not be an option..

Now to the point of this instructable: you have a large quantity of hot tea, which will take ages to cool down before you can put it in the fridge. What to do?

I decided to make a small, kitchen sized immersion chiller to rapidly cool my teas so I can get them straight into the fridge. Similar to what home brewers use to rapidly chill their wort. It will also be an excellent tool when I make large batches of meat or chicken stock. Or when I need to brine a pork shoulder overnight but only remembered to make the brine at 9pm and need to cool it rapidly :)

How does an immersion chiller work? Basically you run cold water from the faucet via a hose and through a copper coil and then out of the coil at the other end, while the coil is immersed in your hot liquid - in this case, green tea. Copper is a great conductor of heat, and the heat from the tea is transferred by the copper to the cold water running through it. You will notice that the water exiting the coil will be warmer, having robbed the heat from the liquid you're trying to cool.
The result is that you can cool down a hot liquid quite rapidly, and then get it straight into the fridge. Instead of waiting for hours for it to cool down on it's own, and risk funky stuff growing in it.

I have been thrilled with how well it works - it cools a 1/2 gallon of hot tea/stock in under 4 minutes! Then straight into the fridge.

I timed how long it took to make a gallon of green tea - using my 4cup French Press for four steepings (each about two minutes) with water at 170-180 degrees F. The entire process from dry leaf to 1 gallon of cool green tea: just under 15 minutes! You will see my process at the end of this instructable. Seriously one of my better hacks - so I hope this helps others who have a tea fetish or other need to cool quantities of hot liquid quickly.

STEP 1: Making the Immersion Chiller - Things You Will Need

What you will need:

1. Some soft, bendable Copper pipe from your local big box (I had some 3/8" copper laying around from a previous project, so used that. You can buy various sized piping - I would suggest not too large diameter so it will be easier to bend. What you DON'T want is the straight copper pipe as it's a different composition and a lot harder than bendy copper pipe. The right pipe will be coiled when you buy it. Probably need 3-4' length, although I confess I didn't measure mine - it was a leftover.
2. Strong heat source - either a propane torch, a high BTU jet burner outside, possibly even a gas ring on your stove. This will be to anneal (soften) the copper ready for bending into the coil.
3. Thick gloves and a wrench or other means of holding the pipe while you heat it.
4. A pipe bending spring (although there are other ways to do it, discussed later on)
5. A round form - I used a full can of glazing putty that was about the size diameter I needed.

6. 3/8" inside diameter poly hose (to match the 3/8" outside diameter copper pipe for a snug fit). How long will depend on how far from the sink you will be, and remember you will need twice the length for hose - supply and return. Type of hose isn't important, as the cooling water won't come into contact with your tea/stock.

7. Hose clamps, if necessary - to clamp the hose onto the copper pipe. I didn't end up using them as the hose was a nice tight fit and didn't leak .

8. A nylon hose barb with 1/2" male thread. This would screw into my faucet (but please note that most faucets have a much finer thread so get one to match your faucet. If it hadn't worked out for me, my next attempt would have been one of those cheap hand-shower attachments for a kitchen sink, the one with a rubber cone that you push onto the end of the faucet. I have a feeling that would have worked as well.

STEP 2: Anneal the Pipe to Make It Bendy

The first step is to anneal the pipe. This is basically to soften the metal and make it easier to bend.

You do this by heating the pipe until it has a pinkish glow and then let it cool. Copper is also convenient in that you can cool it rapidly by plunging in water or let it cool slowly/naturally - not all metals have this property, but handily, copper does.

You can use a propane torch if you have one, I used my outdoor jet burner (the type you get for Turkey fryers) as it was a lot faster.

Use gloves, and hold the pipe with a wrench or similar, as the whole pipe will get red hot. Remember that's why you're using it - because it's an excellent heat conductor. Move it around and make sure you heat it evenly over the entire length you'll be bending. It changes color so you can track your progress as you go.

Cool it fast or slow, and you're ready to bend it into the coil shape.

STEP 3: Forming the Coils

Once the pipe is fully soft/annealed, it's time to form the coil. I used a pipe-bending spring I've had for years - you can get them at the hardware store (mine came in a set for various diameter piping - use the spring that's sized for the pipe you're using).

There are many ways to bend pipe without kinking it...you can fill it with sand and hammer the ends closed, form the coil and then cut the ends off and pour out the sand. Some advocate filling with water and freezing for the same effect. Basically you want to bend the pipe without kinking it, which means supporting the pipe internally or externally while bending.

Working slowly, bend the pipe around your form, in my case a conveniently sized can of window glazing. I slid the bending spring along the pipe as I went.

You want both ends upright and close to each other so it will be easier to wield once you're using the chiller - I spot annealed again at the upright bends with a propane torch just to ensure I didn't kink the pipe after all that hard work.

Voila - the bending into a coil also has the advantage of hardening the copper again, so the finished coil is pretty solid and won't need further support. A final jiggling to get the coils equally spaced and looking all purdy. It's now ready to get cleaned up and attached to hoses ready for use.

STEP 4: Add the Hoses and Faucet Connection

Finally I gave the immersion coil a good cleaning and then attached the vinyl hoses to the intake/exhaust, and pushed on the faucet adapter to the intake end of the hose. The immersion cooler will be in contact with some high quality green tea, homemade beef and chicken stock, etc., and cleanliness is next to godliness...so take the time to clean it well.

There are a few different methods to clean copper...anything acidic will work, I used a vinegar/salt solution to give it a thorough clean and remove all the oxides, then a good soapy water wash.

There might be exact proportions you're supposed to use, but my guess is I used 1/8 vinegar to water ratio, plus maybe 3 tbs salt in a 2 QT container and let it soak for an hour or so. Most internet experts seem to recommend a periodic vinegar soak to get it pink and clean, but the main thing is to clean it after each use with a good soapy wash and rinse.

STEP 5: Take Your Coil for a Test Drive - Make a Large Batch of Green Tea

Okay - time to make a batch of iced tea, your own iced green tea, a large flagon of it ready to consume in the fridge at all times. And not just any green tea, but the absolute best quality tea there is out there. Using my setup, I made 1 gallon of green tea, and it was in the fridge in under 15 minutes.

As far as tea goes, green teas (sipping cup for cup) can often contain less caffeine than black teas, which contain about half the amount of caffeine as coffee - so drinking tea is a great way to enjoy the World's most consumed beverage and not be too concerned about caffeine intake (especially in the evening). If you're sensitive to caffeine, obviously you'll need to find a product that works for you. For iced tea, I usually go green or white tea, and I'm always trying new varieties from tea gardens around the World.

If you're new to tea, please don't buy your tea at the grocery store - chances are good that it will have been on the shelf for up to two years. Tea will easily pick up any surrounding odors, so depending on how well it was packaged it could taste, subtly, of anything. That, or it will taste like liquid cardboard because it was low quality to start with. And don't assume that the tea emporium at your local mall is any better because they specialize. Their tea will sit on the shelf until it's sold as well. There are many sources online for fresh, high quality tea, that could have been on the bush just a few weeks ago. Plus you can also find Fair Trade or Organic varieties if you want. Go explore.

So treat yourself and get the good stuff - it doesn't cost much more and the taste difference will have you hooked for life. And please please please avoid mass produced teabags!! Rant over.

Okay. Having just finished a wonderful bag or "Nine Glorious Mountains", and with my last batch a beautiful "Clouds and Mist Green", I decided to go with the "Pi Lo Chun Imperial", always a winner! (I'm on a Chinese green tea binge at the moment.)

And here is a Green Tea secret: the highest quality Green Teas allow for multiple steepings/infusions from the same pot. You can't do it with many black teas (in general at least - the oxidation process combined with smaller resultant leaf size and boiling temp will produce bitter/astringent flavors and tannins if you try to re-steep), but greens are steeped at a much lower temperature (anywhere from 160-180 degrees F) and only for a couple of minutes at a time, and therefore don't release the bitter tannins that affect the taste until much later.

For a quality green tea, you can reliably get 4 steepings from the leaves, for the highest quality teas it can keep on going. You get great bang for your buck, plus a wonderful flavor balance (the different complex compounds extract at different rates depending on water temperature and how the leaves unfurl). I know - probably more than you wanted to know!

1. Get your water heating...target the 170-180 degree range, depending on your tea. (Fancy kettle like mine, instant-read thermometer, or practice and become an expert in reading when the 'tiny bubbles' equate to the target temp). Do not boil the water, or it's game over and ruined tea.

2. Measure out the tea leaves into the French Press. (Mine is a 4 cup press - use 4 generous teaspoons (1 per cup), or if weighing it would be 5 grams per cup or 20 grams).

3. Steep the first lot for 2 minutes, while topping up the kettle and heating the water again.

4. Once steeped, plunge and pour out brewed tea into a cooling container - I use a 2QT glass jug. By this time your water is back up to temp in the re-filled kettle.

5. Repeat...in my case, 4 times. Sometimes I do an extra one so I can be sipping some hot green while we wait. You will notice with each successive infusion how the dried tea leaves unfurl and expand as they hydrate - it's pretty cool to watch.

6. Now would be the time sweeten, if that's your thing. I don't ever sweeten mine, but if you do, I suggest adding honey or other sweet while it's hot, before chilling.

7. Here we go! Hook up the immersion chiller to the kitchen faucet, turn on the water. I swirled the tea with a spoon inside the chiller coils so that the hot tea is constantly moving over the cooling coils. The tea was cooled in under 4 minutes. I did this twice in my 1/2 gallon glass jug to fill two 2-quart containers.

8. Pour yourself a cup of tea, over ice. Taste test.

9. Pour the cooled tea into a container with lid and get 'er in the fridge.

10. Time for a nice cup of tea and a sit down.

11. In our family, we can consume iced green tea in great quantity, especially in the Summer. This has made the process quick and easy, which is all we ever really want, right?

A final tip - think all green tea is the same? Here's a challenge - do a blind taste test with a few different ones and you will be shocked at how different each one is. For starters I would suggest a Japanese Sencha, a couple of Chinese varietals (perhaps gunpowder and a high mountain green), and maybe an organic green from India or Africa? Side by side, you will immediately notice the 'grassy' notes of the Sencha, the floral Chinese etc. Maybe throw a Jasmine into the mix. Jasmine, btw, is just green tea flavored with jasmine flowers.

Enjoy!

Comments

[spark master]

I like the general idea, but better to make a huge coil put in a bucket of water ice and rock salt then pass the hot tea through the coil, it is called a chiller plate, or the condenser on a booze still. Still nice idea, if water is not scarce. .

Another very nice way to do tea is simple cold water brewing or better room temperature brewing. I have never had a batch go bad in over 25 years. How do I make it, simple make a pot of tea and drink some leave it be, next decant, oh wait that was the cheap me that stopped tossing half pots in the sink b4 commuting...... Ok Ok figure out how much tea to water you like add a bit extra, put in cold water to sit over night, covered). Decant.

Also Black tea is effectively composted tea. I know I know it sounds rude, but, 2 years ago I was was frustrated by tea terminology. I brought a big box of tea, (a gift), to a local Restaurant owner who said the English said Black and the Chinese characters said Red. He and the crew all agreed, tea was confusing to them as in different places it changes the process and the names. So I went to wikipedia and found that black tea is oxidized the most, but another marked black tea is fermented, and it tastes, to me, like compost smells. It is Pu-erh. I went to my favorite Oriental market and paid homage to the Great Wall Of Tea , (it is huge), and brought some home. None of us like it, and the take place owners did not either. Still it is better then cambucha (spling?).

The label on the Pu-erth said black tea, but it is not true black tea unless it is 1st made blake traditionally then shaped, pressed and fermented. Not to make to lightly of it, but, it is NOT my up of tea. And now I will be off to snag a sangwhich and a glass of very nice home-brewed iced tea!!!

[jlpeck]

I live in a small apartment with no outdoor space (no garden hose) and my sink is not threaded the way the author and many posters seem to assume. If I make this, I don't know how I would get water into the system. Is there a known work around? Some sort of setup with a funnel seems like it wouldn't push the water through to the same extent.

[SuperTech-IT]

put container in sink. Add bag of ice and a generous amount of salt to the sink, and fill with water to the level of the tea in the tea container.

Careful, salt in the sink water may cause your tea to actually freeze in the container rather quickly.

[Eric the baker]

There are faucet adapter kits that will screw into just about any faucet out there. They are designed to be compatible with internal and external threads of several different sizes. The output side is usually a garden hose thread, however I have seen them with assorted threads above and beyond that. (the garden hose thread seems the common thread among these things(pun intended))

Here is one at Amazon to give you an idea of what you're looking for. I won't guarantee this specific one will fit your faucet. http://www.amazon.com/LASCO-09-1451NL-Thread-Fauce...

I have seen these available at home brew stores and websites as well. Good luck!

[jayeff]

Though I like the idea with the large coil, I think you are waisting a lot of water if you hook it up to the faucet. ;) How about adding some sort of radiator and have a sufficient amount of water circulating in a closed system?

[craftycounterpart]

Thanks, but want to clarify that you don't have to waste any of it...it's just tap water flowing through a pipe that doesn't contact anything else - so it's still clean when it comes out of the pipe. You can collect it right there in the the sink to wash your dishes, use it to water plants, mop floors, or anything else you might need water for. A closed radiator system sounds like a lot of work to me.

[rundmcarlson]

A lot less work than collecting the water you are cycling through the tube and reusing it. Obviously its going down the drain with that attitude.

[sarge89or]

The planet is a closed system so water never goes to waste. The ecosystem recycles it. If you live in a desert then worry about it. I do not and will let water go down the drain if I want. My water comes from a natural spring and if I do not use it then it just goes down stream to the rivers and then the ocean to be recycled back through evaporation to rain and back into the ground to replenish my spring. It goes from my waste back into the ground, seeps into the springs that feed the river and so on... Eco nuts are so illogical in their arguments.

[gdaily1]

You are spot on. There is no free lunch, and those who think cooling by using an electric pump is somehow more ecologically sound need to understand what is used by the process of generating the electricity. If I want to pay a couple of cents for the use of the water for something it's my money to spend, I'm not wasting water.

[rundmcarlson]

Do you not pay for your water? It is wasted. You are paying for water that you are dumping down the drain when you could be cooling with electricity and a proper heat exchanger.

[FlorinJ]

Cooling with electricity would probably be even more wasteful. Both compressor-based coolers and Peltier elements are highly inefficient, and the process of producing electricity is extremely costly, in terms of water usage. The turbine trains used in power plants are driven by steam, but that's the least costly part, in terms of water usage. Most water is used to mine the coal.

[Omni DIY]

Exactly. It isn't going anywhere. The only major concern is contamination of specific locations.

[dragoon126]

Gonna have to agree with you on this one. I have an AAS in refrigeration and I've needed something like this for a long time for large batches of soup. I've thought of two coils with an aquarium pump, one in the sink basin with ice water and the other in the soup but it isn't practical. I'm just going to go with a much longer coil as my pot is 32 quarts.

[craftycounterpart]

Thanks...you might want to look at the larger immersion chillers used in home brewing. Some use 1/2" pipe, and I know of people that cool their wort outside - connect to their outdoor hose and connect the other end (outlet) to the lawn sprinkler to kill two birds with one stone.

[gdaily1]

Very nice! I make a lot of my own chicken/turkey stock and have had that concern about leaving it to cool slowly before refrigerating. I think I'll take this one step further and get a small pump and connect it to a half-gallon insulated jug and pump ice water through the coil.

[ecochran3]

Crafty, you sound like a passionate connoisseur. Have you put any thought into an 'ible/guide on the various types of teas and the best processes/practices to prepare them? I'm sure there's books, but something much more to the point could be nice.

[craftycounterpart]

Thanks, and yes...I haven't taken enough original photos so far for a full instructable on tea yet, but working on it! I'd like to do a concise tea 101 on the different varieties and how to prepare them, where to buy , how they are made, etc.

[rall2]

Well...I believe the purity of copper has absolutely nothing to with it.

[ramses]

You are also wasting all the energy used to heat the energy in the first place. Instead, imagine this:
A counter-flow heat exchange that has, on one side, your tea and, on the other, cool water that you would like to heat to make more tea!

An efficient design could probably let you recover 90-95% of the delta-Tea (pun intended) into hot water for more tea!

[FlorinJ]

I thought he was using energy to heat his tea, not his energy ...

On a more serious note, true, a counter-flow heat exchanger can easily achieve a very high degree of heat recuperation. But the thing is, you never have any use for it right away.