Do the New Gas Grills Use Lava Rocks?

Gas Grill Function

• A gas barbecue grill uses either natural gas or propane as an energy source. The gas is burned through a burner mechanism with two or more burners. Between the burners and the grill where food is placed there needs to be a material to evenly distribute the heat generated by the gas flames -- a heat diffuser. Gas grill owners control the amount of heat produced by a grill by adjusting the size of the burner flame. High temperatures are necessary to sear meat and lower temperatures can be selected for slow grilling.

Types of Grill Diffusers

• Modern gas grills come with one of several types of diffuser materials. Lava rocks are the traditional diffuser material, but are rarely included in the newer models of grills. Lava rocks have been replaced by compressed pumice or ceramic briquettes. Other grill manufacturers use ceramic grills or plates as heat diffusers. A third option is steel diffusers, often with a corrugated shape to help grease drippings disperse. One manufacturer refers to its steel diffuser as heat distribution plates.

Use of Lava Rocks

• If you buy a new grill with lava rocks, the rocks are intended to absorb and retransmit the heat from the gas burner flames. The rocks should be evenly spread in a single layer and not stacked or piled up. Lava rocks may catch grease droppings from your grilled foods and could possibly flame up in the future, so be careful with rocks that have been used for a while. The lava rocks should be replaced after one or two seasons of regular grilling.

Shopping for a Grill

• If you are in the market for a new gas grill, remember that most new grill models do not use lava rocks, but do need some form of heat diffuser. Check out the design and material of the diffuser for any grill you are considering. Points to consider are if the diffuser can be cleaned, whether it will catch or divert drippings and how effective it will be in its purpose. Look at several grill types and manufacturers to see how each solves the diffuser issue.