Friday, September 10, 2010

Have You Ever Built An Oven?

(CLICK PICTURES TO ENLARGE AND ENJOY)


Under this fancy green picnic blanket lies one of the coolest, most interesting projects Matt or I have ever helped put together and I am very excited to share it with you.  This functional, yet beautiful structure is called a...
cob oven.  A truly old school, fireproof, ancient building material, cob is made of mostly clay, water, sawdust, straw and sand.  Combining all these ingredients gives the cob a more sturdy and resilient structure that clay alone simply would not have.  This week we encountered a new friend, Evan Thaler-Null, who decided to guide us through the building process using his extensive cob oven knowledge, passion and experience.


During the week prior, I had a brief conversation with The Captain, who explained that they had started building an outdoor oven at the farm, but I had no idea that A. ovens could be built outside and B. what to expect when we got there.  You definitely don't see a lot of these in Manhattan, so you could imagine the excitement and confusion that ran through my mind not knowing what we would find.  After a few hours of disappointment, trying to figure out where to put a pizza in this structure below, Evan slowly explained that things were just getting started and this was just a base and not the actual oven.




As we always like to say at HYEPAC, "there is no waste, only potential" and building a cob oven is no exception.  The base of the oven is made from stones found out in the fields and inside this gray cob disk below are as many empty wine bottles that could fit inversely packed against each other.  Evan explained that having these empty bottles creates an invisible barrier of air that prevents heat from escaping through the oven's brick floor and onto the stones which absorb heat very easily.


This disk is slightly taller than the height of the empty wine bottles lying flat on their sides.


These bricks were one of the only items purchased in the making of this oven.  Beautiful looking, delicious tasting and cheap to build??  It doesn't get any better than a cob oven.


These buckets of clay were actually gathered and brought down from a river in Massachusetts, no purchase necessary.  With a bunch of active feet along with some sawdust and sand, the first layer of the oven shell was almost ready to be sculpted, but first we had to lay the oven's brick floor and shape our mold.





A thin layer of sand was set over the gray disk and the oven's mouth was measured 16 inches wide.  This would be large enough for some delicious cob oven pizzas or freshly baked breads.  Are you kidding me? Just the thought of thin crust pizza cooked in under a minute at over 800 degrees makes my mouth water.  

The floor of the oven was evenly and smoothly placed down brick by brick flush against each other, always minimizing air pockets.  It is also important to make sure that the bricks are smooth on top so you can evenly bake your breads, pizza or anything else you experiment with.






Don't be fooled by Matt's earnest pose below, he's actually sleeping in this picture.


To prove it, this next picture was taken 4 hours later, he hasn't moved...very impressive.



Once the bricks were laid, it was time to create the sand mold of the oven cave, which would eventually be covered in a cob shell.  It's important to first place some wet newspaper on top to prevent any of the sand grains from seeping through the tiny spaces between bricks.  If sand gets in there you run the risk of developing larger cracks down the road.





We started small with one handful of sand and The Captain threw in a stick to determine how tall we wanted the oven to be.  Quick physics detail:  The height of the oven doorway should be about 67% of the interior height of the oven.  This small detail plays a big role as this proportion allows for a convection effect to take place.  Air is circulated throughout the oven, baking things evenly just like a conventional oven would with the "convection" setting turned on.  


One thing leads to another and...





BAM!!  A beautiful mold!  The good kind of mold, not the kind of mold you get after you leave your room locked all summer before your senior year of college and unknowingly come back to find all of your belongings and most prized posessions covered in toxic mold because of an unknown leak in your ceiling coupled with a week of torrential downpours followed by an excessive New England heat wave, but I digress.


The key to the shell is to maintain a consistent thickness throughout. Tear off small patches of cob and layer them around the base starting with a ring around the bottom.  This way you can ensure that the thickness is consistent..



 

Adding another layer of moist newspaper on top of the sand mold will help the cob stick.


Don't forget the chimney, although with a big enough mouth a chimney is not mandatory.  It does look damn cool, can't deny that.


Another creative and aesthetically pleasing as well as challenging piece to the puzzle, the brick arch opening. Here Evan explained that using a mixture of clay and straw creates a more sturdy material that helps hold up the weight of these bricks.







Smooth it all around and there you have it, a true masterpiece in the making.  Although this looks very cool and has an incredible arch and chimney, there is still another stronger layer of cob that must go on the outside of this entire structure.  Unfortunately, we ran out of clay, so this will have to be done later.  Once this layer is set, the oven will be left to dry and harden for a few weeks and then finally, the sand mold inside will be dug out, a fire will be lit inside to solidify the structure and it's good to go.



I later found out that this oven is not just for baking phenomenal food, but will serve as a major educational tool for Stone Barns, where they are looking to integrate classes on how to use the oven and all its benefits.  With a little remodeling of the surrounding landscape and the addition of some communal benches, this terrace garden area will be transformed into a more social space where classes can gather and share in the production, preparation and deliciousness of food.  Sounds like a pretty good plan if you ask me.

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