I am a top down fire convert.
At first, I was skeptical. Traditionally, most people are taught to build their fire with the kindling down low, with progressively bigger logs on the top, as flames and heat want to travel upwards. This method of building a fire worked wells so I used it to build fires in my wood fired pizza oven for several years, you can see a photo of this traditional method below.
I recently decided to do some more in depth research on the Top Down Fire, and what I learned surprised me. Now, while it is true that the hottest part of a fire is at the tip of the flame, and fire does like to travel upwards, there are a lot more physics involved. A properly built top down fire will actually outperform a conventional fire every time in more ways than one. Fire knows exactly what to do when given the right set of circumstances, and with a top down fire the flames are actually given the freedom to consume just the right amount of wood and oxygen that is necessary for a completely controlled chain reaction.
How It Works
One of the reasons why top down fires work so well is because the oxygen that is required for combustion can easily travel through the kindling, while the hot expanding gases are in unimpeded, setting the stage for a perfect combustion. The heat at the combustion site travels in all directions equally, so as long as there is fuel (wood) close enough to the heat source (combustion) it will ignite whether it is a move or below. In a conventional fire, the hot gasses have to travel though the kindling, which can choke the fire, causing some of the wood to not fully combust and you are left with unburnt gas (smoke). Additionally, in a conventional fire, the weight of the logs on the top tend to collapse in on itself, whereas with a top down fire the coals drop down to the wood below, helping to preheat and eventually ignite into a controlled reaction.
What You Will Need
How To Build
You can build your fire directly in your pizza oven, or if you want you can build it on a pizza peel like we did here, and slide it into the pizza oven after you have finished stacking your wood.
Start with 3 logs and lay them longways front to back and close together. Place three more logs perpendicular and close together, about 1/2” or less air gap between the logs.
Next place the larger kindling pieces perpendicular to the logs with a small air gap and 1/4” between the kindling
Repeat this step with the medium kindling
Finally, do the same thing with the small kindling, this time leaving only an 1/8” air gap.
Place the tinder on top of your wood pile in the middle. You can soak this in lighter fluid to help your fire start, or place a fire starter on top.
Use special care on damp and high humidity days, this can make it difficult to start the fire.
Bark and rounds are harder to ignite, if you use these do so after the fire has started
Store your wood in a dry, well ventilated area
Invest in an inexpensive moisture reader for the wood
Overall, in my opinion, the Top Down Fire is the ideal way to start a fire in any wood fired oven, regardless of what you are cooking. It has overall less smoke, consistent and faster start, results in a cleaner flue/ventilation and is complete combustion providing more heat and energy per log than a standard fire. Thank you for reading!