Introduction: Build a Caja China ~ Roast a Pig in a Box
So you want to roast a whole pig? Want the coveted title of bbq hero and the immeasurable adulation of carnivorous friends? Then you need a way to roast a whole pig.
THE CAJA CHINA.
It's a Cuban method of roasting a pig in a box. Yes, Cuban. Yes, I know, it means "Chinese box." But the better translation is "magic box." And, oh porky, is it magic. Put a pig in the box, burn charcoal on top, and 4 hours later (flashy magician hands), awesomeness emerges with juicy meat and CRISPY SKIN (see the photos - crackalicious). Heat comes from above the pig -- sounds counterintuitive. But, hey...magic.
It's the quickest way to do a whole pig. Easy to set up, easy to use, portable, and doesn't require much space -- almost any place good for a BBQ grill is good for a Caja China. I've used one on an apartment balcony.
You can buy a pre-made Caja China (aka caja asadores, cajun microwave), but where's the fun in that? Build it yourself. Here are instructions for a DIY and how to roast a whole pig.
I first built a Caja China when two friends asked me to help do a pig roast for their wedding celebration. I'd never done a whole pig before. They initially wanted to dig a pit, but their house is built on stilts, and I wasn't keen on causing their home to tumble down the hill. So I did some research...
Step 1: HOW IT WORKS
>> Here's a primer on whole pig cookery. "But I don't care about that," you say. "Just tell me how to build a caja china, dangnabbit." OK, then, skip right ahead to Step 2. But watch your language.<<
When I first researched how to roast a whole pig, I found four basic methods. I chose #4.
1) "Hawaiian" method
Bury the pig in the ground with hot coals and hot rocks. Dig it up when it's done. Luau. PROS: once the pig is in the ground, requires no active work. CONS: very long total time, requires digging a pretty deep pit, burning a fire down for hours to produce hot coals, finding suitable rocks that can be heated in those coals and inserted into the pig, then burying it completely. Pig comes out moist, but skin isn't crispy. It essentially bakes/steams in the pit. Biggest problem, though, is not having any way to control the heat. You just bury it, then dig it up and pray it's done. If it's not, you're screwed. For a first-time pig roaster, I nixed this one.
2) Spit method
http://www.firepit-and-grilling-guru.com/whole-pi...Put the pig on a spit directly over a fire. Rotate. PROS: Crispy skin. Cons: requires a heavy-duty rotisserie build. Turning a pig ain't easy. Requires constant monitoring and work while it cooks. I nixed this.
3) Cinder Block Oven method
http://cuban-christmas.com/pigroast.htmlCinder blocks are stacked up to create an oven. Pig is splayed flat and sandwiched in a frame so it can be flipped. Foil covers the top. Hot coals are inserted into the bottom corners of the "oven." PROS: pig skin gets nice and CRISPY (arguably the best part of the pig), the pig oven is easy to assemble and break down, total cook time is pretty quick. CONS: need a dedicated flat surface, need 48 cinder blocks, need to store 48 cinder blocks afterwards, need to build a sandwiching pig frame (I had a tough time finding non-galvanized metal at Home Depot -- ***Do NOT use galvanized steel in heat. Gives off toxic fumes), heat control is possible but not easy -- you have to remove a cinder block and shovel in more hot coals. This method came closest to what I was looking for -- until I discovered method #4...
4) Caja China method
http://www.lacajachina.comThe pig is splayed flat and sandwiched in a simple frame (simpler than in method #3), then it goes into a box (caja china) with a charcoal tray (steel sheet) on top, and charcoal is burned on that tray. So the heat comes from the top down. Kind of like a large bbq grill, but the food goes under the fire. Cooks for 4 hours or so on its back, then the pig is flipped so the skin crisps up. PROS: doesn't require a big yard -- can be used anywhere (I've done it on a deck), total control over the heat source (just add more or less charcoal on top as needed), skin comes out ultra poofy crispy, cooks quickest of all methods, and afterwards box can be disassembled. CONS: requires a box, which you can buy for $400... or build it yourself with this Instructable.
4a) This one is a modified version of the Caja China method
http://web.archive.org/web/20050319154203/http://w...Dig a rectangular pit in the ground and line it with foil. Basically, the pit acts as a box (or vice versa, as this method probably came first). Splayed, racked pig goes in, put a steel sheet on top, then burn charcoal on it. Heat source is still on top. I've thought about doing this, but with my luck, my pit would be next to a gas line in the yard, and kablooey goes the pig. I'll try this next time I have an open field.
I've since built a few more cajas and roasted a number of piggies, and here's my current design...
Step 2: DESIGN & MATERIALS
The box is made of 3/4" plywood. Once constructed, it looks like a coffin with a medical stretcher on top. Or the Ark of the Covenant ("Shut your Eyes, Marion!"). The Pig Ark is what we took to calling it.
I've also attached a Sketchup file. My first time using it. You don't really need it -- I just used it to produce the still images here. But if you'd like to rotate it in 3D space just for fun, go right ahead.
Wood for the Box:
- (1) 3/4" plywood, 48" x 24"
- (2) 3/4" plywood, 48" x 15"
- (2) 3/4" plywood, 24" x 15"
You can cut all the pieces from one full sheet of 3/4" plywood (see photo), but I got pieces from the scrap bin.
Cost: $9 (incl cutting).
Wood for the Top Frame:
- (2) 1x3 furring strips, 8' length. [Cut into (2) 6' lengths and (2) 2' lengths]
- (2) 1x2 furring strips, 8' length. [Cut into (2) 6' lengths and (2) 2' lengths]]
- (1 box) #8 x 1-1/2" wood screws
- (36 screws) #8 x 1/2" stainless steel sheet metal screws (NOT galvanized or zinc-plated)
- (1) 20-gauge non-galvanized steel sheet 24" x 48"
Home Depot didn't carry this. I went to M&K Metal Supply (Los Angeles). Found a perfect scrap piece for $5. Make sure it's NON-galvanized. Galvanized steel (aka zinc-plated) gives off toxic fumes when heated. Not tasty.
- (1 big roll) Heavy Duty Aluminum Foil
Get a big box from Costco. It's wider, and it'll last you ages. Make sure it's "heavy duty." None of that cheap stuff. If you want even heavier duty, you could even use aluminum flashing -- but not necessary.
Inside the Box
- (4) bricks
- (3) large disposable foil roasting pans
Step 3: MAKE THE BOX
Before assembling, apply heavy duty aluminum foil to the inside surfaces of the plywood. Make sure the foil extends over all the edges. Secure with a staple-gun. This is the base lining of the box. You'll be adding a second, disposable layer of foil each time you do a roast (more on that later).
Screw together the plywood pieces with the wood screws according to the design photos. Drive a screw every 8". Drill pilot holes if necessary.
The short sides (the ends) of the box will not come up as high as the long sides (see photo). Not a mistake. You'll see.
Now you have a shiny pig coffin.
Step 4: MAKE THE TOP FRAME
The top is essentially a piece of sheet steel inside a wooden frame with handles.
The Long Sides
Wrap heavy duty aluminum foil around the two 6' lengths of 1x3 furring strips -- just the middle 4' that will be in contact with the steel sheet, leaving 1' on either side unwrapped. This is for heat protection.
Now take the steel sheet (careful, sharp edges!). If there's a plastic film, remove it. Attach those two 6' lengths of 1x3 furring strips to the long sides of the steel sheet, overlapping the steel and wood by 1". Drive a sheet metal screw every 4".
The Short Sides
Now take the two 2' lengths of 1x3, and cut them to fit the short sides of the steel sheet so they fit between the frame's long sides.
Wrap them in foil, then screw them onto the steel sheet with the sheet metal screws, every 4".
Now you have a completed frame. But it needs some support.
Place the top frame onto the box. The sheet metal screwheads should be facing down (this is the underside).
Take the two 2' lengths of 1x2 furring strips and wrap them in foil. Remember how the short sides of the plywood box didn't come up as high as the long sides? Insert a 1x2 strip into that 3/4" gap so it sits flush against that notch. Secure the top frame down onto it with wood screws, screwing it to both the long side frame and the short side frame. Repeat with the other side.
These pieces serve as cross supports, but more importantly, they allow the top frame to "lock" into place on the notches of the box.
Finally, take the two 6' lengths of 1x2 furring strips (no need to wrap in foil) and screw them perpendicular to the bottom of the 1x3 strips (see photos). Drill pilot holes first. Make sure these 1x2 strips are not getting in the way of the top frame closing over the box. These pieces help support the weight when the long handles are picked up.
That completes the top frame. The steel area on top is where the charcoal burns (the charcoal tray).
And now you have your own Caja China! To make the box easier to pick up, attach some scrap wood blocks near the corners of the box.
Then it's time for a test drive...
Step 5: TEST BURN
Time for a test burn with the Caja China. This allows any coating on the steel sheet (the charcoal tray) to burn off and to make sure everything's kosher. Sorry, bad choice of terms.
Pick an outdoor location where you won't burn up anything above it (like trees, fire alarms, neighbors). Set the Caja China down on 4 cinder blocks (stood up in their tallest orientation) as legs. You can use bricks or even attach wooden legs. Just need to raise the level up off the ground about 16".
Put the top frame onto the box. Make a "snake" out of some foil, and line that snake around the edges of the charcoal tray to protect the frame from the heat.
Make two piles of charcoal. Cheap Kingsford stuff is perfectly fine. All you need is even heat. Go ahead and use lighter fluid or whatever else you'd like. The fumes never actually touch the meat.
After the charcoal turns white, spread them out evenly. The steel sheet may have warped under the two piles, but don't worry, it'll even out. Let it burn like this for ten minutes. If the Caja is still in one piece, you're good.
Shame to waste this heat, so let's cook something. Take the top frame off, rest it on something appropriate, like two sawhorses. Put a disposable roasting pan down in the Caja to catch drips. Put down four foil-wrapped bricks (placed on their long, thin sides) as corner supports, and put one of the racks onto them. Put two whole chickens onto the rack. Stick a probe thermometer into one of them, and drape the wire along the inside wall, up over the edge of the box, and out.
Put the top frame back onto the box. Cook until the thermometer hits 160 F (carryover cooking will bring it to safe temp). Eat.
The first time we did this, it was the best damned chicken we'd ever had. Good omen for next day's roast. Now clean up the mess, get some sleep, and dream of happy porkers.
Step 6: PREP THE PIG
Get a whole pig. Ask around. Google it. Check Chowhound. Sometimes latin or asian markets will sell them to you, but you have to know the secret password (which is "I am not from the health department").
Get a pig that's 50-70 lbs -- the "dressed weight," meaning after the innards have been removed. Sometimes the kidneys are intact as proof of freshness -- remove them. Head and feet will be attached -- don't remove those.
A 60 lbs. pig will yield about 42 lbs. of meat, which feeds about 80 people (about 1/2 lb of meat per person -- remember, that's not the only thing you're serving).
The Night Before
Get the pig the night before the roast (unfrozen). If you can, have the butcher butterfly (splay) the pig. This means splitting the spine so the pig will lie flat. If the butcher doesn't do that, do it yourself with an axe and a hammer, or a hacksaw. Like this (graphic) video.
After that, inject the meat with a marinade/brine. I used a traditional Cuban Mojo Criollo.
Mojo Criollo (marinade/brine)
- 1 cup sour orange juice (or 6 oz. orange juice, 2 oz lemon juice)
- 1 tablespoon oregano
- 1 tablespoon bay leaves
- 1 garlic bulb
- 1 teaspoon cumin
- 4 teaspoon salt
- 4 oz. of water
- 4 oz. Pineapple juice (optional)
Blend all ingredients and let it sit for a minimum of one hour. Strain through a fine-mesh strainer, or a strainer and then a coffee filter. Don't skip this, or else it'll jam up your meat syringe. Inject the liquid into the meat -- 5 to 6 full shots on each ham (rear leg) and 4 to 5 on the shoulders. Then apply a Kosher salt rub all over the pig.
Wrap the pig back up in plastic and put it in a cooler or the bathtub with bags of ice under and over it.
Step 7: MORNING OF THE ROAST
Bringing up to Temp
On the morning of, you need to get the pig off the ice and bring it up to room temperature. No one ever mentions how to do that safely, though. Leaving a raw pig out for four hours will make a health inspector pop a vein. You know, "danger zone" temperatures. I once waited 2 hours, and the pig was still 40 degrees.
Solution: If you store the pig in a bathtub overnight, just remove the ice bags and turn on the warm water until the pig's up to temp. Easy peasy. Then dry it off as much as you can.
Rack the Pig
Lay the pig upside down onto one of the racks. Put the other rack over it, and use the 4 S-hooks to clip the racks together. Get some help for this. Now the pig is sandwiched. This rack holds the pig in the box and allows you to flip the pig over later. Rub some salt onto the skin, and let it hang out as you prep the Caja China.
Step 8: PREPARE THE CAJA CHINA
Line the entire inside of the box with another layer of heavy duty foil. No need to staple it down. Just lay it in large overlapping rows and press it into the corners to shape it. Leave about 6 inches of heads and tails, so that those ends hang out over the lip of the box. This will come in handy in a minute.
Put 3 large disposable roasting pans into the box to catch drippings. Put the 4 foil-wrapped bricks into place (stood on their long, thin sides) to hold up the corners of the pig rack. Make sure there's some space between the top of the bricks and the top of the roasting pans. If the pans are too tall, they'll restrict hot air from flowing under the pig -- in that case, just fold the sides of the pans down a bit.
Place the racked pig into the box upside down (its back facing down, ribs facing up). Bend the legs if they don't fit. Check the clearance/airflow under the pig again.
Stick a probe thermometer into the thickest part of the ham and drape the wire along the inside wall, up over the edge of the box, and out.
Drill a hole in the side of the box, near a corner, just large enough for another (second) probe thermometer, and insert the probe, poking through the foil, so that it is at roughly the height of the pig. But make sure the tip is not touching the pig or rack or anything else (that's why you're drilling this now, with the pig in it). This is to monitor the oven temperature.
Now take the loose ends of the foil that you left hanging over the lip of the box, and fold/roll them down to create a cushion right along the top edge/lip of the box. This will serve as a kind of "gasket" to help the lid seal better.
Now you're ready to close up the box. Put the top frame on, making sure the cross-piece supports are lined up with the notches of the box (if it doesn't fit now, you may have inadvertently rotated it 180 degrees). Then press down lightly all around the frame, to help seat the top into the foil cushion gasket.
Make sure a foil "snake" is still in place around the edges of the charcoal tray.
All good? Let's roast...
Step 9: ROAST!
It should take about 4 hours to roast. Of course, that varies according to weather, temperature of the pig at the start, how many beers you drink... Use these instructions as a guideline.
Once the oven heats up, the general goal is to keep the oven temperature between 240-260° F. It should take about 3.5 hours for the pig to reach 185°F. If it gets too hot before that, you can lift the lid to vent some heat. If it's too cold, scoop out some ash and/or add more charcoal.
Why not just crank the heat way way up? Because collagen begins to break down into gelatin (which is what you want for fall-apart tenderness) at 160°F. But it's not just temperature-dependent -- it has to be held there for a certain amount of time to really soften up. If the oven temp is around 240-250°F, then once the pig reaches 185°F, it should have been in there long enough for the meat to be easily eaten by grandpas with bad dentures. The guidelines below should be fine, but keep an eye on the two thermometers to make sure it's mostly within range.
When in doubt, open another beer. (see the mandatory hardware attachment in the photo).
Fire it Up
Start with 14 lbs. of charcoal briquettes on top (enough for a single layer). Pile them into two mounds, use lighter fluid (box is sealed, so won't affect the flavor), and light it up. Pre-soaked briquettes are fine too, but only for this first batch. Once they're lit and ashed over, spread them out with a shovel or rake. It'll be HOTTT. Start your stopwatch now.
After 1 hour:
Add 9 lbs more charcoal
After 1 hour:
Add 9 lbs more charcoal
After 1 hour:
Add 10 lbs more charcoal
After 30 min:
Now for the fun. The pig should be at 185°F. Open the box and rest the top frame on something appropriate (between two sawhorses, two chairs, or have your in-laws hold it). Don't worry if it's a little charred -- that's just the underside. Remove the thermometer from the pig. Take some pix.
Now let's flip the pig. Requires two people. Using heavy duty oven mitts/towels/welding gloves, grab the pig rack firmly. Caution, hot. Don't skimp on the hand protection here -- shame to drop the pig now. Let any juices drain into the roasting pans (hot!), then flip the pig and put it back down.
Don't be alarmed by the look of the skin. It'll be dull, pale, clammy, and gummy. But in just 30 min. it'll be the most crack-a-licious pig candy you've ever had.
Remove the S-hooks and pull off the top rack, which was there only to help you do the flip. Removing it will allow your pig to avoid tan lines.
Take a very sharp knife or box cutter and score the skin every 2 inches. The cajachina.com website tells you to just cut some X's into the back, but the point of these cuts is to help the fat drain out so the skin can dry out, poof up, and crisp. So mo' cuts = mo' betta chicharrones. Also, when you're done, you'll have easy cracklin' squares to pull off. Like porcine baklava.
Sprinkle a little salt over the skin. Don't over due it. Just season it a little.
Now put the lid back on. To crisp up the skin, you need to crank the heat up. First, scoop out as much ash as you can with a shovel or metal dustpan while leaving the charcoal pieces. Why? Because ash buildup acts as an insulator, blocking the heat of the coals. Dispose of the ashes in a metal bucket.
The oven temperature should immediately climb. If it doesn't, you might not have enough coals on top -- quickly add a little more charcoal. It's a delicate call because you need enough heat to poof up the skin, but too much, and it'll burn. And you only get one shot at this.
After 20 min., slightly lift a corner of the lid to take a peek. A flashlight might help. If it's not crispy enough, keep roasting in 10 min. increments.
Step 10: THE REVEAL
Now it's time. The guests have gathered. Cameras are out. Smell is intoxicating. Supreme adulation of friends and family within your grasp.
Reveal your masterpiece. Feel the praise, as glowing and effusive as 40-some pounds of hot charcoal. Then move the pig, still on its bottom rack, to a table lined with a plastic tablecloth. I like to place rolled-up kitchen towels under the plastic to form a raised ring or square around the pig. A fortress wall to keep the juices in.
Most of the pork juices should have collected in the roasting pans. You can use it to make a sauce. Or save it for soup. Or ramen. Or just to bathe in. But please, lordy, don't throw it away.
To serve, all you need is a pair of tongs and maybe a knife. Let people at it. Save the cheek and the crispiest piece of skin for yourself. Rejoice.