The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Chemical Composition of Unglazed Clay Flower Pots to be used like a La Cloche?????

Janetcook's picture
Janetcook

Chemical Composition of Unglazed Clay Flower Pots to be used like a La Cloche?????

Reading through old posts I ran across a Cloche type of baking lid that someone made using a regular unglazed flower pot.  While reading through the comments I found quite a few contradicting statements about the safety of using clay pots due to lead.

I am totally confused as some state that it is only the glazed pots that contain lead which is in the glaze...while others state that even in regular flower pots there is lead too that will leach into foods baked with them - even if the food doesn't touch them....

When I googled the confusion only intensified....

So I am wondering if there is anyone here who knows where to get the information that specifies what actually is in a regular flower pot - ie the kind I can buy at my local garden store or Ace Hardware store - so that I can see for myself what the chemical composition is and then decide if it is something I feel safe baking my breads under....if I make one.

Thanks for your help!

Janet

ssor's picture
ssor

The clay flower pots are much the same as terracotta pots and sculpture. This link may help. The clay used is almost always lead free. After you have baked fat into the clay I don't believe that bread could leach anything out. Running them through a self cleaning oven cycle would renew them. http://www.ehow.com/how_4829326_make-terra-cotta.html

Colin2's picture
Colin2

"- even if the food doesn't touch them...."

That part is a little weird.  Clay is ubiquitious -- you can dig it out of the ground most anywhere.  You certainly wouldn't add lead to it in order to make pots out of it.  I suppose it's conceivable that there could be trace amounts of lead in some dug-up clay that didn't wash out, and which then found their way into a flowerpot.  But a normal oven will not even *melt* lead, let alone get it to temperatures that would produce lead vapor.   

 

ssor's picture
ssor

Food contamination by lead is usually the result of acidic liquids coming into prolonged contact with glaze containing lead compounds. Bread fails to meet any of those criteria.

Colin2's picture
Colin2

I've baked on quarry tiles with no worries, & may yet build a brick oven.  Here's to enjoying life.  

Mini Oven's picture
Mini Oven

Orange juice is also one such acid that will leach lead from lead glazes.  Orange juice is also an ideal acid to get a sourdough starter started.  Sourdough starters and their dough could be considered acidic liquids or foods.  Stay away from glazed low fired ceramic tiles as the shine in the glaze is more than likely from a leaded glaze.

Search TFL archives for testing for lead if you are concerned, there are test kits available.  

Colin2's picture
Colin2

Let's be clear, though, that in the context of the OP we're talking about a flowerpot used as a cloche to trap steam during baking.  It's not  even in contact with the dough, and it's unglazed terra cotta.  I agree that you would not want to store a starter in a glazed bowl of unknown origin, but that's because you have prolonged direct contact.

thomaschacon's picture
thomaschacon (not verified)

Unless I can pass a sample through a mass spectrometer, I wouldn't use anything that's not regulated for food safety.

Even the stuff that is regulated is suspect.

I know the temptation: there are so many neat, inexpensive clay/terracotta 'ceramics' that could be used for cooking and baking, but do you dare?

It's the same problem I have with places like Goodwill or the Salvation Army. All sorts of neat things you could use for cooking and baking, but are they food-safe? Ditto the Asian market: I'd love to buy one of those gigantic, 5-gallon, terracotta pickle jars for sauerkraut, but I won't. And the tortilla press I bought from Mexico: varnished with a wood varnish that was essentially poison.

I'm down to stainless steel, glass, and porcelain in the kitchen (with a few wooden things).

;\

#paranoid

Mini Oven's picture
Mini Oven

I've seen those things used with plastic wrap stuck to them.  Each side carefully covered and then dough pressed in between.  Then removed and plastic peeled away.  So I don't think the varnish is a big deal if you cover it before pressing. Now lets worry about the plastic wrap.  

Mini

thomaschacon's picture
thomaschacon (not verified)

I use plasticrap, but boy was I surprised when it arrived.

You could smell the varnish and it was sticky to the touch.

Works like a charm, though! (Just not well enough for Moo-Shu pancakes).

(Kinda' afraid the varish will eat the plasticrap, but something has to kill me).

Doc.Dough's picture
Doc.Dough

Red clay is largely iron-based silicate and aluminum compounds.  Lead occurs in situations where you find silver, zinc, and copper, not where you generally find clay.  Lead is not very soluable in any circumstance and while the metal will melt at low temperature, most forms (oxides) don't melt or volatilize below 1000°C.

There is a clever design of a small tandoor that uses two large clay pots, one inverted on top of the other, and insulated around the outside to enable it to be heated to 700-900°F - and then you slap your naan on the clay to cook it.  If I remember right the whole thing fits in a standard stainless steel beer keg (13 gal?).

I would have no problem with using a red clay pot as a cloche.

 

dabrownman's picture
dabrownman

air we breathe, the water we drink and the food we eat are all way more horrible for you than a clay pot used for baking bread.  First time I saw it, Alton Brown was using his to make chicken.  That was years ago and Alton is still alive although much thinner and his hair is falling out.  But those conditions are because of the chicken not then clay pot :-)

Janetcook's picture
Janetcook

Thanks to all who have responded.  A busy day here yesterday and today so I haven't had time to reply.

Sounds like an investment of $3.00 - $5.00 for a good old clay pot is a reasonable deal as well as being reasonably safe.  The washers and eye will drive the cost up but, hey, I think I can manage it.  :-)

Thanks again to all who responded!

Take Care,

Janet

AnnaInMD's picture
AnnaInMD

Spinnakers.  With each meal they served a freshly baked bread still inside a terra cotta flower pot. A regular flower pot.  Was very yummy :)

anna

dabrownman's picture
dabrownman

it was.  Used to go to the beach there when I lived in Richmond.  Is Spinnakers no longer open?

AnnaInMD's picture
AnnaInMD

but after I switched jobs from nearby Stihl to downtown Norfolk, I didn't go to Lynnhaven Mall much anymore.

But, it was a fun restaurant  "young"   :)

Anna

 

dabrownman's picture
dabrownman

name.  This place was open 5 years ago and was on the first street running parallel to the beach near the Southern end.  They must have repackaged the clay pot bread from the closed Spinnakers and specialized in seafood, which was also very nice.

AnnaInMD's picture
AnnaInMD

the original Spinnaker's was in Lynnhaven Mall.  I just googled Spinnaker's and they had another restaurant in Richmond which also seems closed now.

We only went to the beachfront when tourist season was over and our favorite restaurant with the bestest burgers was The Raven, kinda towards the Southside, and for Italian it was Il Giardino.  My all-time favorite restaurant at the Beach was The Jewish Mother on Pacific Ave. They moved somewhere at Hilltop, not the same.  If you were ever there,  the crayons on the tables and the black walls were so inviting to leave your own artistic murals, grin...

 

 

 

Janetcook's picture
Janetcook

Well, I now can report back that a $5.00 clay pot equipped with a couple of 2" washers and an eye bolt does just as good of a job as a $50.00 Cloche for baking bread.

The idea wasn't mine.  Found it here posted by someone several years ago and I wanted to give it a try since my oven won't hold 2 Cloche lids at the same time.  I needed something with a smaller diameter to fit into the oven along with the Cloche that I do own. This was the perfect solution.

Below are the 2 loaves that were baked together but each under a different 'dome'.  Both lids were pre-heated and placed on a pre-heated Fibermet stone.  I scored one loaf and left one un-scored and it still rose just as high as the scored loaf.  (The loaves were made following Juergen's latest formula for a 100% spelt loaf.)

 

Last week I had baked 2 loaves using the Cloche and a Le Cruset DO.  The one baked beneath the Cloche turned out 100x better than the one baked in the DO which is why I started down this trail in the first place.

Loaves here are from Phil's Desem formula.  Cloche was pre-heated.  DO was not.

 

Crust shot of Cloche loaf.

 Crust shot of Le Cruset loaf.

Thanks again to all who responded to my original post.

Janet

dabrownman's picture
dabrownman

If you buy the clay water drip pan for the clay pot, you can preheat the bottom too and have a complete bread clay baker.  That is what Alton Brown did for his clay chicken roaster - the drip pan kept the juices from running everywhere but for us it is a stone replacement. 

The cold DO really was deflating! 

Nice baking Janet

Mini Oven's picture
Mini Oven

is to put the dough in sooner and add the extra rise time needed to the baking time.  The dough will rise more as the oven is "pre-heating"  until the vessel reaches temperature.  Or start timing the bake as the oven reaches correct temperature.   Dutch ovens (DO) will heat up differently depending on the material and thickness of that DO.  I place DO and cloches in the same category of closed baking vessels.   In order to properly compare them identical vessels must be used baking two loaves of same dough with variations in rise times but same time at specific bake temperatures.  Then a second double experiment using exactly the same procedure changing the two vessels.  

I say do what works for you and your oven.

Janetcook's picture
Janetcook

Hi Mini,

I know my experiment wasn't totally accurate due to the DO being cold.  Both loaves were identical and both were baked at the same time though.  I didn't heat the DO because I have never managed to get a risen loaf of bread into a hot DO without it flattening or me getting burned and then the whole scoring thing is next to impossible so I switched to using it cold because it makes everything easier.  

With some doughs the rise is fine and I do increase the bake time but with this particular dough the difference was very noticeable despite the fact that the DO loaf did bake longer....just never got the spring or the nice crust color.  Like everything I have thus far discovered with baking...nothing is ever straight forward :-) and I delight in the challenge.

Take Care,

Janet

Mini Oven's picture
Mini Oven

one?  I'm thinking the dough in the DO was actually too close to overproofed by the time the dough got up to temperature inside the DO.  Could that explain it?   ("...just never got the spring or nice crust color")

Mini

Janetcook's picture
Janetcook

Mini,

No, both went in at the same time.  I let the DO one bake longer to see if I could bet any color in the crust.  Clearly didn't do the spring as the cloche one did due to the temp. of the DO.  Maybe I will do another experiment with both vessels hot which would be a more 'fair' test but I do not like dealing with hot DOs  :-0  The flower pot/cloche is much easier to handle hot.

Janet

Mini Oven's picture
Mini Oven

the oven 30 minutes before the other one, while the oven is still pre-heating.  :)  ...And then take them out at the same time.

Janetcook's picture
Janetcook

Mini,

Too much time juggling.  With my new cloche I can do both loaves on the same time table.  Just makes things simpler in planning my day.  Too many variables and I am more liable to forget something :-0

Janet

shastaflour's picture
shastaflour

Janet, thank you so much for sharing this experiment with us! If you don't mind my asking, what is the diameter of the pot you used? I'm now wondering if a clay "bulb pan" pot (same diameter, just shorter) would work.  Hmmm... In any case, this is fun stuff!

- Marguerite 

Janetcook's picture
Janetcook

Marguerite,

From outside to outside it is about 10 3/4".  Inside to inside is just short of 10".  It is an azalea pot so it isn't as tall as pot with that same diameter would be.  I wanted 9" but couldn't find one so this is what I got.  Flower pots are flying off of the shelves in the garden shops right now so I may look again when things slow down because a 9" would be a better fit in my oven.  I have never heard of a bulb pot so I will have to check one of those out when I start looking again.

Good Luck and let me know what you find and how it works.

Janet

Mini Oven's picture
Mini Oven

and not as tall as the norm.  Posted by qahtan January 30, 2007

http://i3.photobucket.com/albums/y58/qahtan/general/000_0004.jpg

Janetcook's picture
Janetcook

Mini,

You have a good memory.  I knew I found it somewhere in my searches but was hard put to find it when I WANTED to find it!  That is the one I copied and didn't know it was a bulb pot.  Thanks for letting me know.  It will help when I do another search for a 9" in the future :-)

Janet