It's easy to think that safety isn't important when working
with obvara...no spewing fire...not too much smoke and
no chemical gas to speak of...but still folks...flip-flops
when you are playing with 1600 degrees (F) is not too smart.
Safety should always be a consideration.
“Fermented ceramic is a 4-6 centuries old ceramics technology where the glass-like glaze enriched with metal oxides is replaced by rye-flour yeast. This peculiar, half-forgotten pottery tradition is not the cultural heritage of just a narrow Latgale region, but it is common to the three Baltic countries, Belarus, and Russia, the territory that is united by a tradition of rye cultivation and black bread. Every region has its own name used to designate this type of ceramics: 'rūdītā keramika' (hardened ceramics) or 'melnie podi' (black pots) in Latvian, 'raugo keramika' (sourdough pottery) in Lithuanian, 'обварная керамика' (in Russian scalded ceramics) 'poripott' in Estonian. The English version of the technique is 'hardened ceramic' or 'fermented ceramic'. It is a unique local tradition that is practically unknown outside the indicated region. Nevertheless, at the same time it possesses some similarity with the world-famous Japanese and American raku techniques, whose essence, from the American point of view, is manipulations with just fired and still glowing pottery after it has been taken out of a kiln." http://balticraku.eu/en/balticraku/
But before you go and Google "Baltic"...this is the area across from Sweden and South of Finland. Some of the old Russian "states" if you will.
Essentially, the unglazed piece is taken from the kiln at something around 1400 degrees and dipped into a yeasty mixture, something like a thin waffle batter (we sometimes refer to it as "goo"). The goo is a simple mixture of water, flour (any will do in our experience), yeast and sugar. It's a very "bakerly" or "kitchenery" process...if you know anything about bread baking you will understand what is going on with the mixture. Some folks talk about the mixture "fermenting" but in reality one is developing an environment where the yeast will develop strands of gluten from the proteins in the flour.
As the piece is removed from the goo, the gluten attaches to the pots and forms somewhat of a resist on the pots. Where the gluten attaches, the pot stays lighter (the "white" patterns in the examples). Where the gluten does not stick, the flour in the mixture is left to burn and carbonize the pot. The longer the pot stays in the air after removal from the goo, the darker the carbon markings will be. When the piece has developed a look that we enjoy it is placed into water to stop the process. Dipping the piece into the goo at various speeds, double dipping and direction has a lot to do with the color development as does the temperature of the pot. Because the flour burns, smoke occurs and can sometimes be used to enhance the pot.
The pieces begin to cool immediately as the kiln is opened (duh). Hotter pots tend to be darker when dipped...hotter areas of a pot react the same way. Lips and ridges cool more quickly, so are usually lighter. If the pot is too hot, the carbon is burned away and the pot is bland. If the pot is too cool (it's all relative :-) )...the carbonizing will not occur and again, the pot will be bland. There is about a 200 degree window where all this action takes place. Timing is important as the pot is cooling rapidly through that heat window.
Because cooling has such a profound affect on the color of the pots done in obvara and our pieces tend to be small, we work extremely fast and efficiently.
Of course, being LickinFlames that we are...nothing is completely traditional in our approach to obvara. Like our work with saggars and raku, anything will be tried and everything is negotiable. We burn stuff onto, into, spray, and sprinkle as pieces are removed from the kiln.
The buttons, pins and bowls are individually formed...one at a time. The pieces are dried, sponged, sanded, scraped, terra sigillata and other colored slips are applied, or glazes may be inlaid before firing. There are usually an array of samples in our shawl pin section of our store to give you an idea of the variety we can achieve with our approach.
Still, with all of the control we think we have on the process, working in obvara results in surprises. The colors, textures and patterning will be different on each piece.
Working with the flames of the kiln is the basis of our work. Those “licking flames” are the beginning of LickinFlames.
The “fine print”…
All of the finished work from LickinFlames is safe to use as decorative items but none is suitable for use with food or drink. The work is free of lead and other heavy metals, however, finished saggar, raku and obvara work is inherently more delicate than more common ceramic products. Yarnbowls are durable for the intended use but dropping them onto the floor could cause them to break. The work should not be handled in a rough manner. Garments that these buttons are attached too should be washed by hand or dry cleaned. Explain the delicate nature of the buttons (like a bone or a shell button) and we’re sure your cleaner will understand.