DIY Charcoal Smoker (Oven)

My barbecue has seen better days. The fire pan has rusted away, the air vents have rusted either open or closed and the grill height adjustment controls have fallen off.

In my pursuit of a new barbecue, I came across some amazing, and very expensive products. Being the Yorkshireman I am, I couldn't bring myself to fork out hundreds of pounds on a top of the range all singing and dancing barbecue, and I had also wondered why products in general seemed to be quite polarised in their design. For example, I started gaining interest in smokers - lower temperatures, smoke and long cook times resulting in (apparently), amazing food. But what if I just wanted to barbecue the food like normal - most seemed to be designed to be a smoker or a barbecue. And the smokers, in particular the big green egg, are unbelievably expensive.

With a bit of research I started to come across some quite amazing DIY creations emulating and sometimes bettering the commercial products to come up with versatile and very successful smokers, and all at a fraction of the cost of the commercial products.
So I decided to have a go at creating a smoker. I'd describe what I have now as a working prototype. One main reasons for it being just a prototype is that my little boy (2¾ old) knocked my terracotta pot over, chipped the rim, and sent a hairline crack down the pot (more on that later...).

So, here's what I started with:

One 37cm terracotta pot, bought locally for about £10. The chip and hairline crack hardly noticeable (at this stage).

A grill that fits almost perfectly into the pot. A very similar (but not quite identical) grill is listed on amazon here. The reviewer evidently doesn't like it, but I though for £8 (which is what I paid at a local camp store), it's surprisingly good.

Also in view is a stainless steel kitchen utensil holder to hold the coals, a pan to put on top for the wood chips, and my little boy's leg. Both were bought from Dunelm Mill for less than a fiver combined.

Wow, our grass is bad!

The grill plate: There's also a handle to remove the grill when hot, and under the grill is a drip tray. There's a better picture later. I think this is pretty good, and it fits especially well.

Here I show the utensil holder sitting above the ventilation hole in the pot.

And here it is with the coals burning (lumpwood).

And now with the little pan on top with the wood chips soaking in beer.

Then with the grill in place.

However, after a little while things weren't really getting going. Here you can see the lid - an old terracotta planter I happened to have spare - it was never very good as a planter so I was happy to use it as a lid. I had measured this prior to buying the terracotta pot and you''ll see I was able to get a near perfect match on diameter.

The thermometer was bought on ebay for £4.40 delivered - it took a couple of weeks to arrive.

After some time I realised it was never going to get up to temperature. I suspected that perhaps the pan with woodchips on top of the coals was slowing airflow and lowering the burn temperature so I decided to remove.

Here's the same set up but with the pan removed. I decided to put the wood chips and beer into the drip tray of the grill. Unfortunately this arrangement, whilst a bit warmer, was still nowhere near enough to reach the required temperature. As a further modification I drilled another 8 vent holes into the base of the pot - again, a slight increase in temperature, but not enough. I decided that the utility basket I had chosen for the coals wasn't allowing enough airflow, and moved on to something else...

Here's a new fire basket. It's an old steamer tray for a pan - we've lost the handle that would go in the middle, and we have't used it in at least 5 years so it seemed like a reasonable sacrifice ;o)

Here it is burning. Obviously there's quite a bit more charcoal here, and look at that hairline crack my son created! It's getting bigger.

But this time it had absolutely no problem getting hot. 280°F is on the hot side for smoking, and it actually reached 300°F. I found if I covered the top vent hole with the large round pebble you can see, it came back down to 250°F, so I have about 50°F of control with the pebble.

250°F is perfect for poultry, so on went the chicken thighs and legs.

Chicken going on. I put them on a roasting rack as I realised the grill would be very hot due to the direct heat from the coals, and I want to smoke them, not grill them.

Here's a photo of it cooking. Once it got up to temperature I replaced the pebble and it remained at 250°F for the 1.5 hour duration of the cook.

That hairline crack is starting to get huge though! I think the new fire basket is part of the problem as the coals burn right against the terracotta. Inevitably though I will need to replace the pot for one my son hasn't broken! I reckon a fair bit of heat must be escaping through there as well.

Here's the finished food though. I was pretty impressed with what I saw when I took off the lid - I used a couple of meat thermometers to be sure the meat had cooked and it had, in fact I could possibly have removed it a little earlier. I had checked 30 minutes before and it wasn't quite there. Either way, we simply couldn't believe the flavour and tenderness of the meat. Completely different to a barbecue.

So what next?

• Well obviously a new pot. If I get the same one I know the grill and lid fit, so that's not a big deal.
• Some thermal rope to seal the lid. I was quite surprised at the amount of smoke to come out of the join between the pot and the lid. I've seen others use a seal around this edge so I've ordered some rope (the sort used round stove doors) to create a seal. 
• The roasting rack arrangement isn't ideal. I was thinking I would cook on the grill, but it would be far too hot. I probably need either a well fitting round roasting rack, or better I think, a better arrangement with the fire and wood chips:
• I've ordered a small stainless steel colander - It's wider than the utility holder I tried originally so I think it will make for a hotter burn with better airflow, but won't touch the sides of the pot, so should help reduce the risk of it cracking. Also, others have spoken about roasting for hours with a small amount of charcoal. Mine ran for about 5 hours at a usable temperature (though probably too high). Hopefully the smaller colander will lower the burn rate a bit as I would like to drop the temperature by about 40°F.
• Also, I'm hoping I could put a pan on top for the wood chips, or maybe something in the middle to hold them. I'd really like something to help disperse the heat so it's not so direct on the grill and so I could put food directly on it, rather than have to use a roasting rack....
• Temperature control. OK, the pebble is crude, and there's no control at the bottom. I need to do a bit more research here. I do want to keep it simple, but I definitely need to get the thing burning cooler, and have a bit more than 50°F range. I think sealing the lid better will definitely help, but I suspect I'm going to need to open up the bottom of the pot more, and add a better control. I may need a better control on the lid as well.
• Handles on the lid.
• A stand to mount the pot in - I love the idea in the Cadillac smoker (link below) and the ikea table he's used is only £35. I think once I've settled on an end design and perfected the smoker I might mount it like this.

It feels like winter is coming (September in the UK), so I'm not sure how much more I'll do this year. So far it has been an interesting first endeavour in the surprisingly tasty world of smoking! On the cheap...

Links to other interesting products:
Ceramic Flowerpot Smoker - I found this after building my terracotta prototype. I might keep an eye out for a pair of ceramic pots going cheap as I reckon they are probably thicker walled, more resistant to higher temperatures, the obvious concern being if the glaze contains lead (apparently a lot still do).
Some massive smokers - Some good ideas, but a bit lacking in detail in other areas. Like the colander as a fire box at the bottom.
Build The Cadillac of DIY Flower Pot Smokers to BBQ in Style - This one's really good. I guess this sets the ultimate benchmark in home made smokers. I found this after I made mine!
OMG - this one is something else!!!
Another similar to mine - like the dampers on this one. Quite surprised it burns hot enough with the coals in a flower pot and that my original design didn't. There's a lot to get right in the airflow I think. Maybe the holes were too small in my original firebox.