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How to Season Cast Iron Grill Grates

How to Season Cast Iron Grill Grates

Cast iron grills are quite popular among professional, and home pits masters due to their unmatched durability. Cast iron grills are great for cooking because they conduct heat quickly, cooking the meat evenly while adding a distinct charbroiled flavor that most people love.

Unfortunately, cast iron is very porous, meaning it soaks in fats and excess oil into the pores where they harden-hence the need for seasoning.

Seasoning is the method of burning high-temperature oils to seal the pores on a cast iron, creating a black patina that gives the surface a non-stick black patina that prevents rust and ensures durability. Our article will teach you how to season your cast iron grill grates and why it’s important.

Should all cast iron grill grates be seasoned?

Cast iron is naturally susceptible to the elements, thus requiring more care. It is necessary to season your cast iron grill grates to avoid foods from sticking. Also, seasoning your cast iron cookware makes it durable and rust and protects it from corrosion from acidic foods and natural wear.

How do you season a new cast iron grill?

You’re supposed to season your new cast iron grill grates before using them to prevent stickiness, rust, and corrosion. Also, you will need to repeat this seasoning process every few months unless you notice food sticking on the grill grates. Follow the steps below for cast iron grill seasoning.

Things you need

  • Warm water
  • Dishwashing detergent
  • Scrub pad or nylon-bristled brush
  • Oil: avocado oil, vegetable oil, peanut oil, soybean oil, canola oil, rice bran oil
  • Charcoal


Propane gas grills

  • First, you need to clean your new cast iron grill and grates. Use warm water, dishwashing soap, and a scrub pad to remove the paraffin wax applied to them from the factory.
  • Rinse thoroughly, then dry with a towel. Do not air-dry your grill grates or put them in the dishwasher, as rust will likely form.
  • Spread a thin layer of the vegetable oil over the surface of the cast iron grills with a basting brush or oil mister. The best cast iron grill seasoning oils are organic cold-pressed cooking oils with a high smoke point.
  • Turn the burners on your gas grill to the medium heat setting and preheat it for 15 minutes with the lid closed.
  • Then the grill to the low setting, open the lid, and place the cast-iron grates on the grill.
  • Close the lid and leave the grates in for about two hours.
  • Turn off the grill with the lid closed and allow it to cool down. The grill grates are now well-seasoned and ready for a barbecue.
  • Store your cast iron grill grates in a dry environment to avoid rusting.

Charcoal grills

  • Scrub your charcoal grill grates with warm water and mild dishwashing detergent to remove the protective paraffin coating manufacturers apply to prevent rusting while on transit.
  • Rinse all grates with running water to remove the soap residue.
  • Use paper towels or a clean rag to dry the grates. This step is essential since any moisture remaining in the cast iron pores will prevent oil from absorbing into them during the seasoning process.
  • Lightly spray or spread your vegetable oil over the surface of the grates with a basting brush. Make sure you fill all the pores to ensure they season evenly.
  • Place your charcoal evenly on the bottom of the grill. Use enough charcoal to burn for three hours.
  • Open the vents on the grills completely, ignite the charcoal and bring the grill up to about 350-400°F.
  • Place the cast iron grates on the grill and close the lid for about two hours.
  • Close the vents after two hours and allow the charcoals and grates to cool down completely.

How to season cast iron grill grates in the oven

There is an easy way to season your grill grates in the oven when you don’t want to turn on the grill just yet. Here’s how to season cast iron grill grates or trivets in the oven.

  • Preheat your oven to 275°F to 350°F (135°C to 175°C).
  • While it preheats, wash your grill grates to remove dirt and residue with warm water and mild dishwashing detergent. If your grill is old, use a grill brush or metal scraper to eliminate caked-on residue and crust.
  • Rinse the grates thoroughly with running water and dry with a paper towel or a clean cloth.
  • Lightly coat the grill grates with vegetable oil with a high boiling point and wrap it with aluminum foil.
  • Once the oven has heated, place the covered grill grates in the oven.
  • To avoid oil dripping, you can place a baking sheet on the rack below the grill grates.
  • Bake the grill grates for 30 minutes to an hour.
  • Wear some oven mittens, take out the cast iron grill grates from the oven, and place them in a dry place to cool.
  • Repeat the baking process twice or thrice for well-seasoned cast iron grill grates until the grill grates develop a smooth and even dark patina. Baking it repeatedly deepens the seasoning into the pores, guaranteeing a non-stick surface.

How to season grill grates with onion

Although most people know to season any cast iron cookware with high-temperature vegetable oil like canola or grapeseed oil, some chefs worldwide know the secret to seasoning with onions.

Onions are a great alternative when you do not have high-temperature oils for seasoning your cast iron grill.

Onions and alliums contain sulfur compounds that react with the bare metal to form a hard, non-stick sulfide coating when heated. This sulfide layer is hard to 1000°F. Also, onions have antibacterial properties that will leave your grill grates clean and safe to cook on. Follow the easy guide below to learn how to season cast iron grill grates with onion.

Things you’ll need

  • Large onions
  • Grill gloves or long-handled tongs


  • If your grill is new, clean it with warm water, mild dishwashing soap, and a scrubbing pad to remove oils applied from the factory.
  • Turn on the grill and get it to high heat.
  • Cut the large onion into two halves.
  • Wear your grill gloves or hold your tongs,  then rub the open side of the onion vigorously along the grates.
  • Go over the rails with the onion several times while applying aggressive pressure.
  • After several minutes of doing this, the sulfur compounds from the onion will oxidize and penetrate the cast iron pores, giving a dark layer for non-stick grilling.

Note: Never use salted fats like butter or margarine to season your cast iron cookware.

How to season porcelain-coated cast iron grill grates

Porcelain-coated cast iron grill grates do not require seasoning when they are new. The porcelain coating gives the grill grates non-stick properties and rust resistance without diminishing the benefit of excellent heat retention of the cast iron. However, the porcelain coating is relatively delicate, and abrasive cleaning tools and chemicals will compromise the protective quality of the porcelain.

But proper care, you may never have to season your grill grates. These steps will teach you how to prepare your porcelain-coated grill grates for cooking and maintain their non-stick properties;

  • Turn the grill on high and preheat the grates for about 10 to 15 minutes
  • Then brush the grates clean with a grill brush.
  • After that, adjust your burners to your desired grilling temperatures.
  • After cooking, spray a light coating of high-temperature oil and turn the heat to high to burn food residue off the grates.
  • After about 10 minutes, turn off your grill, brush away the burnt leftover food with a non-abrasive grill brush and then put it into storage.

However, if your porcelain-coated grates are old and are developing rust, they are losing their protective porcelain coating and exposing the bare cast iron. Therefore you will need to clean them, dry them with paper towels and season them with any high-temperature vegetable oil.

To avoid losing the porcelain coating, avoid using abrasive metal scrapers or brushes, and also do not drop the grates as the coating can chip off. Instead, use a grill brush with brass bristles or a wooden scraper to avoid scratching off the porcelain coating.

How often do you season cast iron grill grates?

After seasoning your cast iron grills grates the first time before grilling, continue to re-season them at least every four to five cooks. For frequent grillers, you can re-season your cast iron grill grates after every use to maintain its protective black patina for longer.


Cast iron grills are strong, versatile, and retain heat extremely well, making them excellent for grilling various foods. However, cast iron is high maintenance and requires seasoning to give the surface a non-stick coating. Seasoning your cast iron grill grates when they are new prevents your food from sticking and prevents rust. You will also have to re-seasoning it regularly to maintain its new non-stick surface.