Fermentation Support Forum

I just got an unglazed clay crock (it looks similar to a Romertopf cooker, but shaped like a tall cylinder), which I plan to make bread in, but it would be a great size for fermenting vegetables etc.

However, being unglazed, the clay will be porous. Is it ok to ferment in unglazed clay? I mean, I know it was done for thousands of years and all before glazing, but I have other options these days.

The marking on the bottom says W. Germany, so I'm guessing the clay is less likely to have lead in it than if it were made in China...

The first thing to figure out is whether it holds water. A lot of earthenware will allow water to slowly transit through the material. The concern after that that I've read about is whether hostile organisms will colonize the porous, impossible to fully clean, surface. People have reported that once a mold (for instance) takes hold in such a surface, no amount of bleach will eliminate it. I suspect you can bake any organism off, but I don't know how often you'd need to.

But as you note, people have been fermenting in vessels of every kind for all of history. If it were me, I'd try it and see. But I'd also expect to end up deciding it was more work than it's worth. :-)

I think I will save it for baking bread. I'm kind of nervous about possibly leaching lead into our food.

I may seek out 100% lead free unglazed crocks to make kimchi- I've always wanted to bury it in the ground and make it the old, old fashioned way.

Please look up the link I have here and then ask yourself if you want your kids/grandchildren eating food made in clay or glazed clay pots. I would be very prone to stick with glass. Only.
http://www.fda.gov/Food/FoodborneIllnes ... 233281.htm