I have more fun cooking on Lava Rock than should be allowed. Its a secret you see, right in front of you but hidden. You know if somebody fights or complains about flares on lava rock they dont have the right idea about a secret talent lava rock has, that is unparalleled in the various grill anti flare, heat source protecting, drip catching methods. And its really clean. In fact, its probably the cleanest way to cook because its grilling with steam. Imagine some Hawaiian with some pork cooking on some dying lava on the edge of the sea. The heat makes steam, but the rock is hot enough to sear. Its easy to imagine the quantity of water involved is high. The porous rock produced when hot lava hits cold water has a huge surface area and can hold a great deal of water. The holes caused by the original heat and water created steam tunnels which all lead outside the rock. When I am cooking with Lava Rock its on my grill, which is a high heat source. When I smoke, I could use them in my pan, but usually I am boiling the water enough to keep a moist smoker so I dont worry about it. No, I like Lava Rock on my grill.
I will fire the grill and throw on the burgers say, or sausages. Usually on a medium grill, but tonight it was cool and raining so I had it on high. It sits on the edge of a gazebo so it catches a little rain.
Anyway, under high heat dry lava rock is famous for flaring uncontrollably, but thats just because it misses the ocean. When you add water, or my case I love hops flavored steam so I use beer, things begin to change in that respect. If you run a real hot fire you have to attend it a bit more by adding more liquid, but you can create a cooking condition that is neither pure steam nor pure dry heat but a combination of both. The flares tell you where the rock is dry and thirsty. Give it a good drink and close the lid. Its like pyrotechnics to watch, steam boiling or flares crackling high. The purifying effects of the steam keep the food moist and cleans the grill neatly, and even if the grill flares a bit it doesnt burn the moist food like you would think because the food is moist. If I cook on a low temp, there are no flares as I moisten the rock along the cook, but not much and not often like a high fire would require. Medium heat is in between for time between waterings. To clean too much buildup, which lots of cooking on low can create, imagine it to be like the black coating on a cast iron ware. Black and oily. Fire the grill high and dry and it will self clean. When the fire starts let it burn until the rocks are clean and porous again and you are ready to go. My wife is suspicious, but tonight I cooked 4 lbs of hamburger and toasted the skin on 10 Brats and the grill drank 3 beers.
Afterwards, no greasy build up, even a polished clean hot spot in the middle of the grill. All the black on the grill is carbonized material at this point.