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in this video we're gonna show you how
to build an earthen oven the existence
of ovens like this is easily documented
for the 18th century in fact just about
every ancient culture had a very similar
oven there's one particular woodcut
illustration from medieval times
depicting an earthen oven built on a
wagon there are references in 18th
century literature and also
archaeological evidence that you would
find Evans like this in private homes
and in fort settings there are also
references to communal Evans where the
baker would bake bread for an entire
village we're going to need several
things to make our mud of an out of
we're going to need sand that's the
major component of our oven we're going
to need a good bit of clay this is dried
clay you can get it at a masonry store
or you can get a damp clay out of a
ditch bankrupt you're going to need
straw or dry grass or maybe haste you
may need some bricks so some fire bricks
even even regular bricks will work and
you're going to need a canvas tarp to
mix your cob
together with and you're definitely
going to need a good bit of water before
you build to your oven you have to
consider what you're gonna build your
oven on there are historical examples of
ovens built on tables or on brick or
stone plinths on hearths on the top of
our very sturdy table we've laid out a
layer of fire brick that's gonna be the
floor of our oven we've also chalked out
here the design about 22 inches across
to the bottom on the inside that's the
inside measurement it's going to be the
walls are gonna be about six inches
thick so we've got markings here so we
can see about how big it's going to look
on the surface the door width right here
is about 12 inches across so we can get
something as big as a pie in without too
much trouble first thing we're going to
do is we're gonna build the core it's
gonna be like a sand castle just wet
sand
that we're gonna build the oven over the
top of sometimes you'll see other people
doing it with sticks and things like
this this is gonna be much easier and
quicker we've got this is where our door
is gonna be I just went ahead and put a
couple bricks in here to be the inner
core of the door they'll be removed and
right here I've placed that brick wall
to give us a nice flat surface to build
up against so we've taken about an hour
to put this together we've used very wet
sand so that it stays into shape and
we've got to make sure that this stays
wet till we get our first layer on there
aren't very many critical things about
the shape and the size of your
particular of them but there is one
critical thing and that is the height of
the opening tunnel here compared to the
height of your dome these need to be a
particular ratio or else the air won't
draw through this when you're burning
the wood inside of the thing so this is
a between 65 and 60 percent or about 63%
height here compared to the height there
the next thing we're gonna do is put
paper on this we're gonna put paper
we're gonna wet it down so it'll give us
a layer to separate so when we take the
sand out it doesn't stick to the inner
surface got the paper covering done on
our sand inner core this will make it
much easier to take the core out from
underneath it now it's time to make the
first layer of cob or mud to put on our
oven this innermost layer of mud or or
cob that we're going to put on our oven
is just sand and clay about two parts
sand to one part clay we mix those two
together so that they're very well mixed
and then we just put it on there we
wouldn't want to make sure it's got
about the right consistency that we can
still work it but it isn't so wet that
it's sloppy and you want to make sure to
have air on the side of a little more
sand than too much clay the more clay
you've got more it's gonna shrink and
crack
so you probably want to make up a bunch
of this cob beforehand it ages well it
won't it won't go bad waiting overnight
and that way as soon as you're done with
your sandcastle core you can start
putting it on right away you don't have
to worry about that drying out and
blowing away while you're making your
column
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so learning just the right consistency
that can be a trick as you see here I've
been stomping on this pile for a little
while this is starting to feel really
good it forms up into a ball like a
snowball it doesn't deform easily it's
not sloppy and still form it into any
shape you want and it's not too drippy
either that's what you're looking for
something it holds together well but
still moldable so we're working on
putting this first layer on this is a
layer without any straw in it because
that would just burn up anyway it's
about three inches thick and we're
starting at the very bottom we're gonna
work our way up that way we can watch as
we go to make sure thickness stays about
the same
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well we finished the inner mud layer
yesterday afternoon and we let this set
overnight and it's it's just slightly
firmer than it was we don't want to let
it get too dry or else the next layer
won't adhere to this layer properly
we've scratched this layer a little bit
so that the next layer of cob we put on
here will adhere nicely this next layer
of cob that we put on it's going to have
grass or hay or straw in it to give it a
lot more strength than this inner layer
we're gonna mix our clay and our sand
first as soon as that's getting close to
the right consistency that's when we'll
add our other binder material here
so I've got this mixed up I'm gonna let
mix this up just slightly wetter it's
feeling a like a pretty good consistency
now under my feet
and since we're since we're gonna add in
this dry straw here it's gonna dry it up
a little bit so I'm gonna start with a
slightly wetter mixture but we wanted to
get this mixed first and then add in the
binder this will add some amazing
strength to it when it dries up it
really binds it together so it's helpful
to make this cob up beforehand it really
makes it work better if it's a couple
days old but you don't want to let it
get too old because as it's wet for a
long time the grass will start to rot in
there so you don't want that to happen
if it's a day or two old keep it wrapped
in plastic so it's wet and pliable it'll
really work even better after a day or
so so to make this go faster
I suggest you invite a bunch of friends
over have a cob party they can be
stomping on this stuff while you're
putting it on your stove everyone will
have fun well I've got about five or six
Wolf's of big loaves of of cob here
ready to go I think that's a good start
I'm not sure exactly how many it's gonna
take to cover this oven so we're gonna
put this on and then I'll see how much
more I need to make
I've got marks here on the table to get
about two-and-a-half or three inches for
the outside layer we're gonna start
putting on our lopes we're gonna make
sure that they butt up well with the
inner core here so there isn't a big air
space between them and I'll just start
adding these on all the way around
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okay there it is we've got the second
layer of a cob type material on here
this is the stuff with the straw that's
that's built into it it does as you work
it it kind of sags down some so you
might want to start a little thinner at
the bottom than the finish expecting
some of it to Sag down into position a
little bit this gives us a good
opportunity to look at the cross-section
but what's going on here you can see the
cobs little thicker down at the bottom
than it is at the top because it's kind
of sagged a little bit you can see our
outer cob core our inner core that
doesn't have this straw in it and here's
the sand core on the inside we're going
to add a little bit to the outside here
we're gonna give it a nice rounded
opening because a rounded openings gonna
have more strength than this sharp edge
well we've finished putting our rounded
opening on the oven so it'll be a little
bit stronger we made sure to make the
the cob that we added back into this
other stuff whenever you add two pieces
together we really have to work it so
that the two pieces adhere to each other
and it just doesn't fall off we added a
little bit of sand on the front to help
support that lip depending on where
you're at your environment the time of
year but what the humidity is this cell
takes two weeks three weeks four weeks
maybe even a little longer for it to get
dry enough for it to even you start to
even think about warming it up from the
inside while this is drying you don't
want to get it rained on so you're gonna
need to protect this from the weather
but don't cover it with plastic so that
it can't dry so you want to protect it
from the rain but let it breathe
so it's only been about 24 hours since
we've been here last but it's firmed up
enough with how the weather is here that
we were able to go ahead and pull out
some of the same that I haven't gone and
dug the whole thing out but I want to
let it start to dry out on the inside
and even peel off some of the paper if
you want to but at all burn out anyway
but we're just dug it out about half way
we'll come back in a couple more days
take out more we've removed the sand
core from this oven and we've given it a
couple weeks to dry so it's almost ready
to fire you may not have to wait this
long if you build an oven but if it's
not adequately dry before you fire it
it'll cause cracking or at least more
cracking than normal in the body even if
you wait like we did it's inevitable
that some cracking will occur don't be
alarmed if the cracks are especially big
you can repair them with a little extra
sand and clay and let that dry in place
we've employed a few warming fires in
the seven and it's and is dried out well
we've gotten a few cracks but overall
we're really pleased the walls of this
oven are extremely durable here's a
brick of the material and it takes a lot
to break this material up so if you need
to do modifications you'll really have
to chop at it however is as sturdy as
this is it still needs to be protected
from the weather this is water soluble
and it'll just wash away with the rain
so we need this to last a while we're
gonna have to build a little roof over
it make sure to watch part two of this
video where we learn how to bake bread
in one of these earthen ovens you know
this looks pretty good I think I'm gonna
fire it up
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