I've had a request to talk about what to do with a new kama. So I dug through my notes from years past and here are some brief things to note. Even if you have a used one, it is a good procedure to use. Most of the teachings I've had in the mizuya about care of utensils have been from my sempai, so I'd like to acknowledge them for the information that follows.
Once a kettle or tetsubin is cast, it is coated on the outside with a patina called ohaguro, "tooth-black" and the inside is coated with lacquer or some synthetic. To "cure" a new iron kettle or tetsubin, fill it close to the brim with fresh, filtered water, especially if the water in your area is high in minerals. You'll have to have a source of such water anyway, since minerals change the taste of the tea. To this water you may add Japanese sake and/or green leaf tea, old matcha, even black tea as a last resort, and boil for several days or until the funny smell and taste goes away. You must boil the kettle for several hours at a time, replenishing it with pure water to keep the level topped up. After this treatment be sure to do one treratment of just pure water lest you find a soup when you go to make koicha.
Do not boil directly on a gas burner. Rust is the oxidation of iron. Oxygen in the water vapor in the gas fire will rust the bottom of kettle just as fast, maybe faster than leaving it out in the rain. Best case is boiling over sumi, charcoal. So if all you have is gas, put an iron plate or something in between so that the gas does not get near the kettle.
Some new kettles have a glass-like inner coating on them which is supposed to prevent rust. Nevertheless it is only a good cautionary practice to rinse and boil even these kettles once or twice before making tea in them.
May 14, 2011
Care of your kama
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This is great information. May I ask about how much sake/matcha/tea leaves to add to the kettle of water each treatment?
ReplyDeleteTea apprentice, thank you for your comment. I have just used a handful of leaves to boil in my kama. Old matcha that has turned color and no longer used for drinking can be used as well. I don't know, maybe a couple of tablespoons? Half a can? What ever is left over that you would probably throw out? I would never waste sake in boiling a kettle, drink it while you are waiting for the water to boil, but that is just my preference.
ReplyDeleteYour instructions on care and use of the kama are wonderful. Thank you very much!
ReplyDeleteMay I ask a question, please? I bought an old tetsubin (no lining, just pure cast iron) to use for home practice until such time as I can manage to buy a proper furo and kama. Unfortunately it has some rust. What is the proper way to remove rust on a kama or tetsubin when it is already present? Many of the instructions I've read involve (re)seasoning cast-iron cookware with oil of some sort, which doesn't seem to make sense here.
Anonymous,
DeleteThank your for your comment and for your question. These iron kettles, without the inner ceramic coating to prevent rust are very highly prized. A certain amount of rust is inevitable with iron tetsubin and kama. I have been told to not worry about it, and even if you scour the inside, in time it will rust again. I was also told that the rust keep the kettle from deteriorating. I have had a very ugly inside of a kama with rust and black stuff that was very gross, sandblasted to get rid of it, but you wouldn't want to do this very often.
You must, however care for your tetsubin and kettle. Do not pour hot water directly into it. If you are going to put hot water in, make sure there is some cold water in it. I fill my kama with hot water, but first I put about 1/3 cold water, and pour the hot water into the kama by pouring it into a bamboo scoop placed inside the mouth so that the water will run out of it into the kettle. I overfill the kettle to the brim and then with the hishaku scoop out several cups of hot water and ladle them over the outside of the kettle until there is one scoop height of space in the mouth. With one final scoop of water, I cover the kettle wtih the lid and ladle the hot water over the lid. Then I wait a few minutes for the water to evaporate off the kettle, blot the bottom and put it on the electric element.
At the end of class in the clean up, I ladle out about a kensui worth of hot water. Then I take several ladels full of hot water and rinse the outside of the kettle. I turn the kettle over to empty it and rinse the bottom with hot water from the kensui. If you have a kama brush, rinse the bottom and brush the bottom lightly a couple of times. Turn the kama over and lightly blot the bottom inside. Then return it to the fire (or electric element) and dry the kama over the heat. You can tell it is dry by passing your glasses over the mouth and no moisture forms on it.
For tetsubin, do not over fill it. The water should come to the middle of the spout on the inside. Care for your tetsubin is similar to your kama.
Thank you for the great question.
I have a Furo that someone soaked in vinegar to get the rust off and then used a copper brish on the inside to clean the rust out. The outside was once black, but now seems to be stained from the vinigar. Is there a way to restore the black color back to the Kama. I was told that rust in a cast iron kama is almost inevitable, but the person I got it from used some shabby methods to clean it up. How can I restore the black color to the kama?
ReplyDeleteDear Christian, Thank you for your comment.
DeleteTannic acid is a common substance used to modify the iron surface, and so boiling tea to release tannins is one treatment. Black tea or Bancha seems to do the trick. So perhaps immersing it in a larger pot and boiling it in tea may help restore it.
Comment on Facebook: I have rescued a kama that most thought beyond rescuing by doing the boiling bancha in it method that you're describing. The water went from being black (I kid you not) to pretty much clear. The trick is in quantity and time, a lot of tea for a long, long time. I did this for days and days and days, perhaps over weeks even. I just had it on a low simmer on my stove and kept boiling it with bancha and dumping the water and boiling it over again. And again. And again. Every time I would think it was hopeless I'd redouble my efforts and put her back on the stove. It was a long process but I was so happy I stuck with it--I feel like a I have a special relationship with that kama for having spent all that time with it, listening to its matsukaze for so long, letting it humidify my house for days on end. Plus it was so gratifying to be able to rehabilitate it and bring it back into use. Don't give up on your kama, just give it lots of time to leach out its funky stuff and I bet you can bring it back from the dead. As long as it holds water and doesn't have whole big chunks of iron breaking off and into the water, I bet it's salvageable.
Another comment from the thread:
My recipe (so far) for restoring a kama is this: 1) 6% acetic acid (spirit vinegar) for 3-5 days, until there is a decent scum of rust on top of the vinegar; 2) rinse out, and scrub with stiff bristles the entire inside; 3) boil once with clean water to clear out the residual acid; 4) boil 6x for 1 hour each with cheap black tea for maximum tannin content; 5) boil with clean water 1 hour each 6x.
I hope it helps.
Margie
Margie,
ReplyDeleteGreat thread. I have a kama that my three-year granddaughter was playing with. (Actually was popping the bubble wrap that was being used to protect the kama). Anyway, it appears that there is some discoloration on the outside, perhaps due to the child's oily hands. Can this stain be removed by the methods described above. David
Hi Margie,
ReplyDeleteI have two sets of Kama/furo, both with natural iron on the inside of the kama. The design of the furo's mouth and the stand where the Kama rests are different. Does this signify where or when they were made? Also, the most recent one was 'oiled' which concerns me. I was told by the seller that it is a preference by the owners to protect the iron. Wanted to get your thoughts on the matter. I would like to send you pictures if you would email me at lawrells@gmail.com. Gassho, Lawrell
Dear Lawrell,
DeleteThank you for your comment. Sometimes antique dealrer will pair up a furo and a kama that were never meant to be together and sell them as an integrated set. Thank being said, if the kama fits the furo, I see no reason why you cannot use it. Oiled kama? Oiled furo? I do not believe that it is a preference for most owners to protect the iron. Perhaps it is a mistaken thought of the seller who has no experience and likens iron furo to cast iron frying pans. I will send you an email.
Margie