Jump to content
terrim8

raku tea cup - food safe?

Recommended Posts

How do you make a raku cup -food safe usable? I've always treated it as purely decorative not for food items but I've seen raku tea cups. Do  you just use clear or white glaze or safe stains in a clear glaze base without metal oxides? It invariably has fractures through the glaze so how can it be usable?  Hand wash only?

Share this post


Link to post
Share on other sites

They're for decoration.  Just because someone is selling it for tea doesn't mean it's ok to drink tea from!

You can always use a crackle glaze on the outside and fill the cracks with ink and it will looks similar

Edited by liambesaw

Share this post


Link to post
Share on other sites

i have always wondered how the ones actually used in the tea ceremony differ from the way raku is done in the US because i know they are drunk from.  where are the folks who know this?

Share this post


Link to post
Share on other sites
16 minutes ago, oldlady said:

i have always wondered how the ones actually used in the tea ceremony differ from the way raku is done in the US because i know they are drunk from.  where are the folks who know this?

You might be confusing Japanese raku and American raku too.

As far as food safety in Japanese raku, the raku is porous but only tea is used so the whole sanitary thing isnt as much of an issue as if they were drinking their tea with milk or something.   Tea ceremonies are a special occasion so they're not being used on a daily basis. 

 

American raku with container reduction and metal oxides is very not good for functional ware.

Edited by liambesaw

Share this post


Link to post
Share on other sites

exactly.         not confused.    i am trying to find out the difference.    i know that only tea is used in the tea ceremony and that the cups are not in daily use.     i am trying to find out what makes the original, true raku,  able to hold water, (tea) without leaking all over the user.     i know that the usual raku pieces made here are absolutely not useful for holding anything wet.       what is the difference in manufacturing them that makes them so different from each other.

Share this post


Link to post
Share on other sites

They're porous in Japan too.  I don't think most people use raku for tea ceremonies though, my inlaws have tea bowls that are locally made and appear to be high fired stoneware.  

The Chinese use yixing ware similarly, the idea is that the tea that is absorbed into the body helps condition the teapot or tea bowl and it becomes even better over time.

Edited by liambesaw

Share this post


Link to post
Share on other sites

I have used commercial low fire glazes on raku without the reduction step in the trash bin.  The glaze looks like regular earthenware.  They should hold water ok.  Never used as drinking ware,but probably just as good as earthenware.  My understanding of the Japanese process fires to higher temperatures which means lower porosity.  

Test and see.  The American raku glazes are most likely not stable in some drinkable  liquids, so glaze studies would be needed.

l have fired some ware to cone 10 with a liner glaze and then refired to raku temps with raku glaze on outside; proved it worked, became bored and moved on to more interesting challenges. 

LT

Share this post


Link to post
Share on other sites

With an Raku, the body is purposely underfired, which allows it to handle the thermal shock, of being unload at the temps they are.  As @liambesaw mentioned, that means they are porous, whether it be Western Raku, or Traditional, Japanese Raku.

Not only is the clay body porous (Which is one aspect the users like because it insulates better, and doesn't create a sharp sound, when the stirring/ mixing material hits the rim), but some of the glazes, used in the Traditional process, do have materials that could leach.   The reason that the Traditional wares can actually be used, is because as part of the ceremony, the bowls are meticulously washed and cleaned.  So any potential contaminate is washed away.  Also, as @liambesaw also mentioned, these are not use everyday.

 

I made my sister a decorative set of tea bowls (Western Raku process), several years ago.  I explained to her, that they were only for decoration, and were porous, and could potentially leach materials into food or drink.  A few years later, my family were talking about various items I had made for them.  My sister chimes in with, "I use those Raku bowls for Mac and Cheese."  I looked at her and said, "Stop that!"

Share this post


Link to post
Share on other sites

Has it been considered that the users of the Raku tea cups and pots over the centuries were/are not concerned about food safety? Here in the US , because of our litigious society, safety  and warnings of such have become so overbearing that if you were to live your life in such a manner that if you read and followed every warning on every device, food, or function, you would be afraid to get out of bed (and there is probably something detrimental about that, too), IMO

JohnnyK

Share this post


Link to post
Share on other sites
31 minutes ago, JohnnyK said:

Has it been considered that the users of the Raku tea cups and pots over the centuries were/are not concerned about food safety? Here in the US , because of our litigious society, safety  and warnings of such have become so overbearing that if you were to live your life in such a manner that if you read and followed every warning on every device, food, or function, you would be afraid to get out of bed (and there is probably something detrimental about that, too), IMO

JohnnyK

I think the eye towards food safety is probably not a hyperbolic step in the wrong direction.  We don't use lead in glazes anymore because we know that there is no safe exposure to lead.  Why would you make an item that's purpose was to be used for food, that you know would cause harm to someone else?  I understand if the item was made in ignorance, like before lead was considered harmful, but now that we know is there any reason to purposefully harm someone?  I don't think so.  Some of it is fear of litigation but I think most people just don't want to cause others harm because they're thoughtful.

Share this post


Link to post
Share on other sites
12 hours ago, oldlady said:

i have always wondered how the ones actually used in the tea ceremony differ from the way raku is done in the US because i know they are drunk from.  where are the folks who know this?

There is no definitive or cohesive way to define “japanese raku” in terms of materials, methods, or safety standards. The work is as diverse as everyting else in ceramics. There are probably vessels being used for tea ceremonies that are safer than what we consider “western raku” and probably some that are less safe. It’s not a monolith. Put in perspective, drinking tea from a porous vessel is probably not as bad as cigarettes or donuts. 

Share this post


Link to post
Share on other sites

The Raku tea bowl is one of those places where context matters as far as food safety goes. 

Making a Eurocentric style coffee or tea cup in either Japanese or North American raku styles is going to result in an impractical piece because of how people expect to be able to use it. In both cases they're underfired, there's thermal shock fractures, the glazes are soluble, and in some cases the colours are fugitive if not sealed against the air and oxidation. It's not going to stand up over time to daily hand washing, never mind the dishwasher or microwave. The object itself isn't going to hold up to that kind of use. If you run it through the dishwasher on the sterilize cycle, pull it out and use for coffee the next morning, get distracted by the kids, find it an hour later, put it in the microwave for a minute.... pop goes the cuppa. Maybe not the first time, but I've done that with a stoneware cup that was just cracked, never mind something that is a lot less structurally sound.

In a tea ceremony, the whole thing is about being present, and in the moment, and about savouring the whole experience. There's a mindfulness and a sense of care that just isn't in that last scenario.  

Share this post


Link to post
Share on other sites

My friend brought me a raku mug a few months from southern Mexico. It has a  clear glaze inside. I lead tested it and it came up zero. The main issue with it is it weeps-. If you fill it with watewr the clay body over a pretty short time frame will get wet. The tip of handle is the last point to saturate. 

If one was to use it for drinks whatever you are drinking slowly seeps into the clay body-milk-juice -tea ,whatever. I see it as unusable except for water-and for that you need to pay attentention putting it down as that surface will be getting wet.

Maybe we westerners pay to much attention to this but I really do not like weeping pots.

In terms of hurting one with any poisions ,I do not feel thats the case at all

its more of a nappy clay full of organics from the fluids. In some cultures this may be a desired deal just not in mine.

Edited by Mark C.

Share this post


Link to post
Share on other sites
16 hours ago, terrim8 said:

How do you make a raku cup -food safe usable? I've always treated it as purely decorative not for food items but I've seen raku tea cups.

Were they raku or faux raku? There is a potter in my area who makes ware that looks like raku but it's a stoneware or porcelain body with a white crackle glaze on the outside that's been stained. Not saying that the raku tea cups you saw weren't raku but as others have said it wouldn't be a good idea. Think we've all probably seen pots that make us cringe due to inappropriate glazes on wares intended for food use.

re doughnuts: I think we're okay Ben, Mea was talking about donuts not doughnuts, phew! 

Share this post


Link to post
Share on other sites
7 minutes ago, Min said:

Think we've all probably seen pots that make us cringe due to inappropriate glazes on wares intended for food use.

re doughnuts: I think we're okay Ben, Mea was talking about donuts not doughnuts, phew! 

What about those wares, that were glazed with radioactive materials (Fiestaware)!  When it comes to getting the colors we want, potters will use about anything!

Also, in regards to the doughnuts, Whew, I was worried for a second.  I forgot that donuts, are something COMPLETELY different.  Doughnuts are basically health food!

Share this post


Link to post
Share on other sites

Well it looks like the consensus is  to use the  actual raku process for decorative items. I think the most striking point against  making tea cups  was durability and modern life - dishwashers, microwaves .... They are attractive but durability is important :)

This is an example of what I was seeing online that started the whole thing :   https://www.instagram.com/explore/tags/rakuteacup/?hl=en

 

 

Share this post


Link to post
Share on other sites

I think in the tea ceremony the cups are not set down for any length of time after filling, they are kept in the hand, cleared and washed immediately. Not really enough time for seepage.

Maybe I'm picky, but reheating coffee in the microwave for a whole minute on high seems excessive and makes the coffee taste awful. 30-40 seconds should be plenty, unless it's a Big Mug, imho. :) 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

By using this site, you agree to our Terms of Use.