Guest Article: Flower Pot Tandoor
Andrew is one of my favourite cooks on Twitter and Instagram. He is constantly turning out really unique and innovative dishes on a weekly basis. One of the things I try to do is cook different things on the BBQ, and Andrew really shows that almost anything can be cooked over a naked flame.
Some of the cooks Andrew has cooked have been done using his Flower Pot Tandoor. This is such a great idea and you will see from some of the photos below what a wide range of cooks he has produced and how great they look. I need to say a huge thank you to him for writing up this article and sharing how you can build your own Flower Pot Tandoor.
I’d love to see a few more of these popping up!!
What is a tandoor?
A tandoor is a cylindrical oven traditionally made from clay. Heat is generated from a charcoal or wood fire in the base and thick clay walls retain heat resulting in much higher temperatures than conventional ovens. Tandoors are most commonly associated with Northern Indian cuisine, although their use is more widespread. Food can be cooked in the central chamber of the oven, often on skewers such as tandoori chicken or directly against the heated walls like naan bread. The high heat and smoke created from dripping juices give a delicious flavour profile.
Why make a tandoor?
Commercial tandoor ovens are very large and costly and I began reviewing designs that could be made at home, light enough to be portable and relatively low cost. This is where I came across the flower pot tandoor. This is not my original idea, in fact, there are so many variations online dating back many years it is difficult to identify where the design first came from. Through trial and error, I have worked through several designs, which I share below to hopefully help you avoid my mistakes. If you find any ways to improve this method please do share!
What is it made from?
Garden flower pots are commonly made from terracotta, a form of baked clay, they are readily available, low cost with good heat retention capacity. The walls of a clay tandoor oven are much thicker than the average terracotta flower pot, for this reason, the flower pot version requires an extra layer of insulation to retain heat. This one uses vermiculite, a naturally occurring lightweight mineral used for commercial insulation that can be found in builder’s yards. Vermiculite also retains water like a sponge so another place to find it is in garden centres where it is used in hanging baskets and failing that could always be ordered online.
- Angle grinder and safety equipment (goggles, mask and gloves)
- Drill with masonry drill bits (to avoid cracking pots)
- 3 unglazed terracotta flowerpots as shown in the diagram below. Glazed can contain lead-based paint and should be avoided.
- One large external pot (blue)
- Two smaller pots that fit end to end to make the cooking chamber (green) and firebox (yellow). The base of cooking chamber removed with an angle grinder to make a lid (red dotted line). Charcoal represented by black
- Inverted terracotta plant saucer or rim of the terracotta pot to raise cooking chamber (orange)
- Vermiculite (grey shading)- volume will depend on size (I used about 1/3 of 100L bag)
- Terracotta feet or house bricks to lift tandoor allowing inward airflow from underneath
- Optional extras
- Smaller terracotta dish to sit inside firebox and support charcoal for ease of cleaning
- Cover or lid to protect from elements
How to assemble
The two internal pots can be any size but should fit together snuggly ideally with the cooking chamber (green) pot overlapping the firebox (yellow) to give a tight seal and allow a ledge to form making it easier to position skewers. There should be at least a 2cm gap from the edge of the cooking chamber to the external pot (blue). The amount of charcoal required is relatively small so if possible go for a larger cooking chamber as shown in the diagram. I found a bowl-shaped pot for the firebox works best and the rim inside allows easy placement of a cooking grate for searing.
The firebox (yellow) needs to be elevated so it is not sitting directly on the external pot to avoid the risk of cracking. You can use an upside-down plant saucer with drilled holes or a circular off-cut from another pot, this works well and easier for height adjustment.
When you are happy with the fit and height of the pots drill holes into the base of the external pot (blue) and firebox (yellow). The pots already have one large central hole for drainage and I have found another 4 provide enough airflow (but you can make more if needed). Ensure the holes are at least 1cm diameter to prevent blocking with ash. If you’re not confident start with a smaller drill bit and then increase the size. If using an inverted plant saucer (instead of circular off-cut) ensure the holes align with the firebox.
The top of the cooking chamber should be cut off 1-2cm from the end using the angle grinder (wearing appropriate safety equipment) to form a lid. You do need an angle grinder for this as initially, I got through quite a few saw blades. Some methods cut the lid into 2/3 and 1/3 sections like a cake as shown below, with the idea being that you can keep the tandoor partially covered while cooking. I think it is easier to keep the lid a whole and slide as necessary during cooking otherwise smaller portion can sometimes fall inside. You will need to use gloves when handling the lid once it’s fired up as it gets very hot!
When the components are in the correct position pour in the vermiculite around the sides lightly pressing down until 2cm from the top of the cooking chamber. Use the bricks or feet to elevate the external pot and you are ready to go! If you like you can place a flat plate underneath to catch any ash that falls through but there is usually so little I don’t bother.
The flower pot tandoor is remarkably energy efficient given the excellent insulation and requires only a small amount of charcoal. A third of a standard chimney starter of charcoal is usually enough for a cook lasting several hours. I previously used to light the charcoal in a chimney starter and pour into the chamber but on one occasion this caused the firebox to crack. If it does crack don’t worry too much it generally doesn’t affect the performance but now I light the charcoal in the firebox using odourless eco-friendly firelighters. Avoid using lighter fluid or blocks as the terracotta is porous and can absorb unwanted smells tainting the food. When lighting keep the lid off for 15-20 minutes until the coals are glowing then replace it until reaches the desired temperature.
I have used both charcoal briquettes and lumpwood. I have reached higher temperatures using the briquettes probably as they fit more uniformly into the fire bowl, but they do produce a lot more ash which can affect the airflow after an hour or two. Now I stick to lumpwood and very easily hit temperatures above 370C (700F) within 1 hour of lighting using an infrared thermometer gun to guide me when it’s time to start cooking.
When it comes to cooking there are many ways to use for flower pot tandoor and the fun is in experimenting. You can use skewers, place above the firebox for searing, hang food into the cooking chamber or cook naan bread on the walls.
Cleaning and storing
I find using a small plant saucer at the base of the firebox helps with the clear up but you will need to drill holes to align with firebox for air flow. This can then be lifted out when cool and the ash disposed of. Any remaining ash can be pushed through using a soft brush. To remove ash from the bottom (orange) section carefully tilt the flower pit tandoor and use a bottle brush bent to 90 degrees to sweep around and you’re ready to go again. The tandoor can be kept outside but as vermiculite is very absorbent it can take a long time to dry out if it gets waterlogged and limit the temperatures you can achieve until it is fully dried out so I keep mine in a sheltered spot using a plastic plant saucer as a cover.
Thank you for reading and please let me know any questions or improvements!