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Obvara After Pit Firing

Obvara pit fire trial witchs brew

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#1 Evelyne Schoenmann

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Posted 08 May 2014 - 01:42 PM

Tomorrow Friday I will start the long expected Obvara-after-a-pit-fire. We discussed Obvara in a thread of Marcia's already, but now I will try to get a pit (and not a raku kiln) as hot as possible to be able to do Obvara. I started the witch's brew 2 days ago and, on the first day, I got a nice fermentation, 2nd day it was just a liquid mass, today I see fermentation again (lather), but the liquid was never warm (except when I started the brew with warm water).

 

Question: shouldn't a fermenting brew be at least luke warm? The fermentation is a chemical reaction isn't it? And that leads to warmth?!

 

I kept to the known recipe:

10 lt luke warm water

1 kg flour

2 packets of yeast (our packets here in Europe are 10 grams per packet - and yours in the State?)

1 tbl spoon of sugar (I took whitte sugar)

 

Any tips and tricks you can give about the pit fire getting hot enough for the Obvara firing are very welcome!

 

Thanks. Will keep you in the loop. Will go to bed now, it's almost 9 p.m. here. See you tomorrow.

 

Evelyne


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#2 Marcia Selsor

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Posted 08 May 2014 - 02:05 PM

Sumi used a blower connected to heat ducts ind buried in the pit with 1/4" holes drilled every 12" or so on both sides.
The blower was a simple squirrel cage blower.

Keep your fermentation warm.And stir well often especially before using.


Marcia

#3 Evelyne Schoenmann

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Posted 08 May 2014 - 02:22 PM

Thanks Marcia!

 

How hot did she get the pit?

 

Bucket with the fermentation is in a warm room, beside the heating. I'am stirring it 4x/day.

 

Hope all goes well tomorrow....


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#4 williamt

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Posted 08 May 2014 - 04:23 PM

Your liquid should ferment just fine between 70 and 80 degrees F. Cooler the fermentation happens, just slower. A little warmer, faster. It's ok if you don't see lots of foam. Kinda like doing a rise in yeast bread. Curious, did you use regular or the rapid activating? I think the regular does better when activated at about 37 deg. C before adding it to the brew. And I think the packets here are about 8 grams.
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#5 Evelyne Schoenmann

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Posted 09 May 2014 - 11:29 AM

Thank you, Lee, for your encouragement and for your help. There has been lots of foam again today. I don't understand what you mean by regular or rapid activating? Are there different kinds of yeast available in the States? We have only the yeast here we use to rise up the dough of the bread. Very normal yeast in my eyes. The liquid looked all right today I guess. Did you do Obvara too?

 

So the outcome today wasn't exactly what I was looking for. We had too much (unexpected) wind that was pushing the smoke right back into the pit (and onto my bowls and discs). I was firing 2 hours and too much of my ceramics came out of the pit black. There was also a bit of searching for the small ceramics pieces in the pit full of embers, and then first emptying the bowls of the embers over the pit, and then going to the bucket of liquid.... so maybe the ceramics was already too much cooled down? And another question would be if the size of the object is relevant too? Because when I did Obvara 2 weeks ago, firing in a raku kiln, we had vases 7 inch high and they got nice brown colour. Now my bowls in the pit were all approx. 3 inches and maybe that's too small for getting colour? Hmmmm... so many questions. Good that I can attend Marcia's demo in Certaldo!

 

Btw: Marcia, can I bring 2 more of the small bowls to Certaldo? Two of the ones I fired today? Can we put them into the raku kiln with the other ware and get the bowls white again and start anew with the Obvara? I would bring then 4 pieces of approx. 3 inches if that's all right with you.

 

I enclose two pictures of todays results. The second picture shows the only bowl that really got brown colour. The others are mostly black/brown.

 

Evelyne

 

PS: just added a pic of the pit, 2 mins before I started to take the pieces out. In the background, left, the bucket with the Obvara liquid, to the right the water.

Attached Files


Evelyne Schoenmann
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#6 Tyler Miller

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Posted 09 May 2014 - 04:04 PM

Evelyne, 

 

I think you're a hero for even making the attempt.  The results may not have been quite what you're looking for, but I think they're pretty nice even still.  The little brown bowl is especially nice.  I look forward to seeing more results. :)

 

As for yeasts, there are different kinds here.  There are fasting acting yeasts as well as traditional.  When I was in grad school, I lived in a building with an old Croatian woman who explained the trials of her mother trying to get bread to taste like what she made in Yugoslavia.  Triple rising wasn't something she did there, but had to adapt her method to the flours over here to let the gluten relax.  There's MUCH higher protein in North American flour, and Canadian bread flour is among the hardest on the planet--not counting durum wheats.  Sometime in between now and then, yeasts were developed to make the triple rise a lot faster, and then bread machine yeasts came out in the 1990's making the process faster still.  I would imagine that where you are, the yeasts would be simply traditional style, by North American standards.



#7 williamt

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Posted 09 May 2014 - 09:48 PM

Evelyne,
The yeast is the same, just processed differently before packaging. The rapid rise is in smaller particles, dissolves easier and is used in bread machines. The regular is a little chunkier and is usually dissolved in warm water prior to adding to bread dough.

I've not done Obvara, but will have to try the technique.

I have done some open/pit firing of late using bisque raku with raku glaze.

The pieces you have done are actually quite nice. I like the texture.

I'll be interested to see more of your work

Lee
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#8 Up in Smoke Pottery

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Posted 09 May 2014 - 10:51 PM

Thanks for sharing.


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#9 jrgpots

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Posted 09 May 2014 - 11:02 PM

How did you end up making the pit (size and dimensions) and what type of air supply did you go with?

I hope you get the wind to behave with your next try.


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#10 neilestrick

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Posted 10 May 2014 - 12:06 PM

I made a new sourdough starter last year using wild yeast, that is not using yeast from a packet. Just take flour and water and let it sit out. Every day feed it some flour and water. After about 3 days it started to smell awful, like it was going bad, which it technically was. By day 5 it had started to bubble a bit as the good yeast started to take over, and by day 7 it was good and bubbly and smelled nice and yeasty. Basically the good yeast have to build up and take over the bad stuff. Not that any of this is exactly the same as what you're doing, but it gives you an idea of how the mix can change. But you've got to feed it every day to keep the yeast active and the mixture bubbly. With sourdough bread, making a starter with wild yeast gives you a greater variety of organisms in the mix, resulting in better flavor and texture in your bread.


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#11 Evelyne Schoenmann

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Posted 10 May 2014 - 01:13 PM

Tyler: thank you so much for your kind words! And also for the enlightenment about the yeast. No, we don't have fast acting yeast here. Only either a fresh lump of yeast that you have to crumble into hot milk and let is dissolve. Or the same yeast, but dried and fine grained and packed in packets of 10 grams. I used the dried one. Interesting how many yeasts you have in the States!

 

Lee: thank you too! I used porcelain and flax increased porcelain (the black and white pieces in the pic). Then I used 3 different clays from the same producer (Baillet, France) with 1. no grog / 2. a bit of grog / 3. very heavy grogged

 

Up in smoke: :)

 

Jed: Normally I use the pit only for pit fires. I started with a pit 1x1 meter, 1 m deep, 4 years ago. But with time and pit fire after pit fire, the pit got wider and deeper. My gardeners use it for burning twigs and foliage when I'am not in Italy >grin< I don't have air supply. I look at the weather forecast and when it says: dry, warm and a modearte wind, that's when I start a pit fire. I have a blow pipe for my chimney, looks a bit like a didgeridoo, and I use this to blow into the pit when I think I need more air. But normally we always have enough wind here in the hills (oftentime too much....).

 

Neil: thanks for sharing this very interesting bit about yeast. I'am always one for trying new methods! How was your bread in the end?

 

Thanks again to all of you for all your infos and encouragement. I appreciate it very much!

 

Evelyne


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#12 neilestrick

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Posted 10 May 2014 - 01:51 PM

My bread from wild yeast is much more flavorful, and has way better texture. It's not crumbly like with the packaged yeast.


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#13 Marcia Selsor

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Posted 10 May 2014 - 02:58 PM

Evenlyne,
I like the little brownish pot as well. Pretty decent results. Bring a few more pieces. Not sure how many pots we'll have since we'll also be doing raku dolce with orange terra sig. We can talk about pit designs. here is the pit Sumi had built for the Edina , Mn alternative firing workshopAttached File  SumiPitwithpipe.jpg   56.12KB   4 downloads

#14 Evelyne Schoenmann

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Posted 11 May 2014 - 02:27 AM

Neil: thank you for the info. I guess it's worth a try!!

 

Marcia: chief question is whether I can bring 2 of the already pit fired pieces and we put it in the raku kiln to get rid of the black? I don't want to spoil the other pieces if the burning away of my black pieces leaves traces on the ware in the kiln!

 

That's a nice pit of Sumis'. It's way bigger than mine. Clever idea with the tubes! But I think I have enough air in my pit with the wind that we always have here in the hills. My pit is approx. 1 m deep and approx 1.20 x 1.20 meter square.

In the fire 2 days ago I wrapped one of the discs loosely in aluminum foil (strong, good quality) and after the 2 hours firing the foil was 3/4 melted and a part of the foil clung to the clay. So I think I got at least near to 800°C (1'472 F).

 

Evelyne


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#15 alabama

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Posted 11 May 2014 - 01:54 PM

Okay,

Maybe I'm missing something, so I'll ask, "Is Obvara the new Pit Fire word of the day?"  Noun or verb?

I'm familiar with "primitive fire" and the mis-nomer of "pit fire", but I've read both references to Obvara and

nothing is coming together.

 

Oh, I've fired greenware in the snow.  Its not a issue, with the photos with only footprints, a fire, and vessels are a plus.  Very pristine.

 

Thanks in Advance,

Alabama



#16 Evelyne Schoenmann

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Posted 12 May 2014 - 02:20 AM

Hey Alabama

 

Obvara is a (some say) glazing technique after the firing, coming originally from Belarus. You make a vessel, bisque fire it, then put it in the raku kiln, take it out by 900°C and dunk it into the bucket with the Obvara liquid. (The liquid is: flour, yeast,water and sugar - let ferment for 3 days). Here is a very interesting thread about the Obvara http://community.cer...ring-technique/

started by THE Obvara specialist here, Marcia Selsor.

 

I tried to do Obvara (the dunking the pieces in the Obvara liquid) after firing my pieces for 2 hours in a pit (instead of a raku kiln). I wanted to see whether I can get the pit hot enough for the liquid to adhere to my pieces.

 

The expression: Primitive firing (or alternative firing) methods, in my eye, covers pit firing, smoke firing, drum firing, black firing, wood firing, Anagama and all the related kilns, salt firing..... and maybe raku? Did I forget one or the other?

 

What do you mean by "mis-nomer" (pit-fire)?

 

Thanks for your interest Alabama! Firing greenware in the snow-do you have pics to show us. Very cool!

 

Evelyne


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#17 williamt

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Posted 12 May 2014 - 11:08 AM

This thread is fascinating. I looked back at the post that Marcia did (enlightening). Someone asked why go thru the fermentation step. I would say that the transformation the yeast does on the flour, by metabolizing it, is what makes this surface treatment work. Also, the dipping solution is now full of yeast that have processed the sugar and flour and concentrated the result into their wee little bodies.

If you know a brewer or vintner, it would be interesting to get the mash from a production run and use that for the Obvara liquid. It would be a bit more complex solution chemically, but basically the same as the regular Obvara mix.

I might have to try that.... :)

Lee
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#18 alabama

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Posted 12 May 2014 - 02:43 PM

 

 

The expression: Primitive firing (or alternative firing) methods, in my eye, covers pit firing, smoke firing, drum firing, black firing, wood firing, Anagama and all the related kilns, salt firing..... and maybe raku? Did I forget one or the other?

 

What do you mean by "mis-nomer" (pit-fire)? 

 

do you have pics to show us.

 

Hey Evelyne,

 

        I use the term "primitive firing" for firing greenware.  Most people bisque the pottery in order to do raku, drum firing, kilns, smoke firing, and pit firing.

While it is not impossible to pit fire greenware, its mostly improbably because the loss of inventory would be so high, you'd need to bisque for future firings.

I say its a mis-nomer for a couple of reasons, 1.  None of the 4 methods of heat transfer can work in a pit.  2.  For the pit to work, you'd have to widen it to the point

where there wouldn't be a "pit" left.  "Pits" are a modern invention.

 

      This Obvara is similiar but not exact to the traditional potters of the Ivory Coast.  They make a large pot of boiling tree bark which contains tannic acid and when the vessels are finished, the small ones are dipped in to the mixture to make spots and blotches on the exterior.  Brooms are soaked in the mixture and flung

on the larger vessels for the same effect.  In Alabama we call Obvara - Homebrew. ;>)

 

      See You later.

Alabama

 

 

 

     



#19 alabama

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Posted 13 May 2014 - 12:45 PM

 Then I used 3 different clays from the same producer (Baillet, France) with 1. no grog / 2. a bit of grog / 3. very heavy grogged

 

 air supply. I look at the weather forecast and when it says: dry, warm and a modearte wind, that's when I start a pit fire. I have a blow pipe for my chimney, looks a bit like a didgeridoo, and I use this to blow into the pit when I think I need more air. But normally we always have enough wind here in the hills (oftentime too much....).

 

 

Hey Evelyne,

      I think the pit is working against your means of control.  The black smudge marks are caused from incomplete combustion which is what the pit causes.

(thats kinda how charcoal is made)  When charcoal has complete combusion its ash.   To get the temps you want, you're going to use smaller wood,

maybe 1" to 3"...and they are going to have to be dry..(.I covered that in a burnishing post.) I think the larger pieces takes too much energy to burn resulting in the incomplete combustion.  Besides, when you have vessels in the bottom of a pit and a log rolls down, the sides of the pits direct the wood onto your pottery.  Its better for the fuel to roll off and away than onto.  (A voice of experience)  Wind causes  complete combusion and works in your favor, both in markings and control.  As for temperatures, incomplete combustion wil be cooler than an open fire.  So you may want to try your experiments using the same clay body, same shapes, and different regulations in the structure of the pit.  Deep v.s. shallow.

     It is the temper that compensates for wind.  Not enough causes cracks, right amount is perfect, and too much causes cracks.  So you'll have to experiment on that level as well.  For me, I use about a 35% to 55% mixture, maybe more if the clay is storebought and the discision of the right amount is determined

by drawing a wire tool thru and examining the particle drag.

     I like the others, like the brown jar...  The shape and design are similiar to the Northwestern USA Iroquois pottery.

     Oh, rotten limbs seem to burn hotter than solid wood.  I've talked a park into allowing me to pick up their fallen rotten limbs. :)

 

Good luck with your endevors...

Alabama



#20 Evelyne Schoenmann

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Posted 13 May 2014 - 02:25 PM

Lee: that is a very good idea, ask a brewer or a vintner for mash! I have to try that. We have mash here in autumn from pressing the olives. It's very oily and when I do the Obvara in autumn again, I add some of that to the brew too. I love experimenting!!

 

Alabama: I thank you very much for all your thoughts and ideas! I appreciate it very much that you take the time to explain things. A pit, for me, (English is not my mother tongue) is a hole in the ground/earth, instead of firing the pieces in a fire above the earth (like the pathfinders do their BBQ). I'am doing pit fires for years now and was, all in all, content with the results. If I would have made a pit fire last Friday and let it cool for 24 hours, I would have been content with the pattern on the pieces (at least the ones that aren't completely black). But I wanted only to heat them to a temp where I could take them out and dunk them into the Obvara liquid and get brown patterns. I used twigs and oak tree bark (the bark was approx. 1 year old) for most of the time, all completely dry. Only 30 min before I took the pieces out did I add logs (men arm thick, meant for the chimney), also completely dry.

 

Doing pit fires for ages, in the last 3 years I never had cracks or broken pieces again. I also fired pieces that I wanted to stay as white as possible, and shifted the wood always away from the piece, so that no twig or log could fall on the piece and make those (nice) black spots. And I achieved that. Only not last Friday.... >sigh< But I won't give up! Will experiment some more until I get the result I'am dreaming of.

 

Again, thank you for your help!

 

Evelyne


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