Preparing for the Cooking Chamber

We are almost to the point where we will begin building the actual cooking chamber where fire will be built and all of our delicious breads and pizzas will transform.  But first, we needed to lay a foundation for the oven.  First we need to put down a layer of calcium aluminate.  Then we will put down a pad of high temperature concrete before laying down the firebrick.

The calcium aluminate comes in fifty pound bags that look like this:

  
This substance is then mixed up into a damp, form-able sandy stuff (but not too wet).  If it didn't likely cause cancer, it'd be a pretty fun thing for kids to play with.

Then shovel it up and put it in the form and pat it down.

I went home for dinner, but they kept doing it. They laid down the metal grid for support in the middle, and then continued to fill until they got to the top of the wooden form. Here is a shot of the finished product without the frame.

Almost done with the base

Today we were lucky enough to have another sunny beautiful day. I'd say 90% of the base is completed.  Our dedicated volunteers finished the dry stack (four high), core fill, and then prepped the area over the ash chamber.  We also hauled a ton of cinder-block up to the worksite.  On a side note, Mike's cement mixer died.  It had served us and about five other brick ovens well, in addition to its prior life mixing cement for something that we are not at liberty to know.

The next step will be making a high-temperature cement pad (made with calcium luminate) on top of our base and regular concrete covering the rest. Then, we transport and unload our high temperature firebrick and start building the cooking chamber.

Here are some shots from this afternoon and this evening.  First, we have the hauling of narrow cinder-block.

Then we finished the top of the base. Specifically the area above the ash chamber was done with wet cement rather than the patio pavers.

Finally it was time for a victory pic.

Note: All volunteers are not pictured. This was the end of the evening, so there were many who were doing the hard stuff all day who went home to eat with their families.

All about that base...

On a glorious Sunday afternoon, we started building the base of the brick oven.  The seven of us started at about 1 o'clock and pooped out at about 4. The base of the oven is kinda like a basement. It supports the cooking chamber and all the other parts of the oven that get far more oohs and aahs.  I'd say the coolest part of this phase is making sure there is an "ash chamber."  Instead of shoveling hot coals and ash out of the oven and putting them in a nearby metal garbage can, this oven will have a narrow slot at the front of the oven. When needed, the baker can shovel/rake/brush the ash forward and it will fall through the slot.  About once a year the ash chamber will be cleaned out.  It's much safer than messing with hot coals and ash.

We got about halfway done today.  In the pictures below, you'll see the shape of the oven start to reveal itself.  The cinderblocks are drystacked, and then rebar is put through the holes.  Finally, rocky cement is troweled into the hole, which makes it a solid mass.

Here's the oven laid out. The math people did the measurements and the chalk lines.

Then we got some concrete going.

Once we got it figured out, then we stacked the block, filled it with concrete and stuck in the rebar.  Note the block in the middle. Those blocks will ultimately support the solid top/surface of the base.

 

Then cement was shoveled into the ash chamber and smoothed out.  Later there will be a small door on the side of the oven to clean out the chamber.

Pouring the Concrete

Well, Thursday morning we passed our city inspection.  He looked at our concrete forms and compacted gravel and declared it done.

After that, we had to make a decision as to whether to go forward with the concrete pour the next day.  The weather experts were predicting light rain all day. I was told that drizzle is fine for pouring concrete, hard rain is not okay.  Early Friday morning, our local weather geek, Paul Douglas, stated that the heavy rain will "pinwheel" to the south and Weather Underground stated that there would only be one tenth of an inch of precipitation.  So, with that, we green-lit the pour.

At 3:30 in the afternoon, the masses of volunteers assembled.  It was a phenomenal turn-out of Hamline students (thank you Dean Sickbert and Coach Rogosheske). We also had church folks, neighborhood folks, and friends.

Prior to the arrival of the concrete, we moved a lot of the concrete block and bags of concrete (the stuff we will use for the oven, not the concrete pad) very quickly.  I think we moved over a ton of materials in about ten minutes.

The concrete went in quickly, celebrations were had by all, and the bulk of our volunteers headed home. Then the rain came....and it was not one tenth of an inch.  My faith in Paul Douglas has been slightly shaken. He will need to work extra hard for me to trust his forecasts again.

A tent was erected.  We got cold really quick, and the slab was saved.

Checked it out the day after.  It survived the night.  Hosed it down, and then we'll start building the oven base tomorrow afternoon.

Preparing the slab

What is that old verse about a house built on sand....well, we're working on creating a rock here, so no worries. We had a great turn-out on a sunny day. Finally, after much planning, we broke ground on the community brick oven and this project was becoming very real, very fast.

The day was filled with activity and a lot of laughter.  While part of the hearty volunteers dug out the grass and dirt, the more skilled amongst us built the wooden form for the concrete pour.  Once we got to the right depth, we added and compacted Class 5 gravel.  Finally we added rebar to offer some structural integrity to our base. I was also glad that when Gopher One came out to the property (pre-dig) there were no gas, water or electrical lines that were found.

The next step is calling in the Saint Paul inspector, and, hopefully, getting the go ahead to pour the concrete this Friday. Stay tuned.

 

Here comes the stuff...

This was an exciting week, we received delivery of a lot of materials that will be used in Phase 1 of building our oven.  I almost had a heart attack when the semi-truck pulled up with four pallets of cinder block, a ton of cement, and an assortment of boards and insulation.

It's hard to believe that it'll take all of that to make our little community oven, but, if you want something built to last, then this is what it takes. The difference between our oven and some of the "instant" wood-fired ovens that you see on-line is the insulation. Our oven will get hot and the bricks will retain the heat for several days, so that we can utilize the full heat cycle of the oven.  If an oven is not insulated well, you have to keep a fire going, which is fine for pizzas but not so good for bread.

What you see below is over four hundred cinder blocks (used for the oven base...the cooking chamber will be fire brick and the exterior "skin" will be brick), rebar, sand, 2,800 pounds of mortar mix, and 1,000 pounds of portland cement.

Slowing Down, Meeting Neighbors, and Baking Really Good Bread

For a long time, there was just one oven for an entire village.  It was inefficient for every person to have their own oven, and so the community shared a large oven in the center of town. In the process of baking, people would meet friends, discuss politics, share stories, and gossip. In addition to producing good food, the community ovens produced good neighbors.

That old idea is now coming to the Hamline-Midway neighborhood in Saint Paul.  This spring we will begin building the Community Brick Oven at Hamline Church, and hopefully we'll be eating some wood-fired pizzas and baking many loaves of awesome bread by this summer.

News, information, and random thoughts will be posted on this blog. So stay tuned and visit often. Construction of the brick oven will start in April. It will be a community effort. Anybody who would like to volunteer to help is welcome to sign-up for a volunteer slot (more information about signing up will be posted soon). Once completed, we'll focus on learning how to fire the oven and use its full heat cycle. Then, the fun will really begin.

Before we get too far ahead of ourselves, however, we must step back and thank White Bear Lake United Methodist for awarding us a grant to build this community brick oven in the Hamline-Midway neighborhood. It is the vision and support of Pastor Bryce Johnson at White Bear Lake United Methodist that sparked our imagination and made this possible. It's also the technical expertise and construction know-how of Mike Faust that is going to get this project done.