New Corten steel grills often produce smoke and odors during their first use, which is completely normal. This occurs because residues from the manufacturing process are burning off, and the steel is also beginning its natural “seasoning” process. This process typically lasts for the first one or two uses, and as long as the grill is operated correctly outdoors, it poses no health risks. This guide will explain the reasons behind this phenomenon and provide instructions on how to properly handle the important initial lighting of your grill.
1. Introduction
If your new Corten steel BBQ grill emits smoke or an unusual odor during its first use, the good news is that this is usually completely normal. Many first-time users worry that there is something wrong with the grill, especially when they notice white smoke, a metallic smell, or a slight chemical odor during the initial lighting. In most cases, this is simply part of the initial seasoning and curing process.
Unlike standard painted steel grills, weathering steel (Corten steel) has unique properties because it is a special alloy designed to form a protective layer on its surface over time. During the initial heating process, the grill undergoes several natural and manufacturing-related changes that may temporarily produce smoke and odors.
This guide explains the causes of smoke, how long it lasts, how to distinguish between normal and abnormal behavior, and when it is safe to start cooking.
This Is Completely Normal
First, it’s important to understand that smoke is normal during the first use. Almost all metal grills, especially high-end stainless steel grills, go through a “seasoning” phase.
This process removes:
► Factory protective oil
► Manufacturing lubricants
► Packaging dust
► Shipping residues
► Moisture accumulated during storage
For weathering steel, the first high-temperature cycle also helps accelerate the formation of the initial rust layer, which is key to its long-term durability.
What Causes the Smoke and Odor
Smoke typically originates from the following three main sources:
► Protective oils and anti-rust coatings are used during manufacturing
► Dust and fine particles are generated during packaging and shipping
► Oxidation reactions on the metal surface when heated
Each of the above situations may produce visible smoke and temporary odors.
Duration and When It Is Safe to Cook
Generally, odors and smoke will significantly decrease after the following periods:
► Initial preheating: 30–60 minutes
► Second preheating: 15–30 minutes
After two preheating cycles, the grill is usually ready for cooking.
2. Manufacturing Residues Burn Off
Factory Protective Oils and Coatings
During the manufacturing process, manufacturers typically apply a thin protective oil film to the surface of the steel to prevent flash rust and ensure the steel remains safe during shipping.
When heated for the first time, this oil will burn off completely, producing:
► White smoke
► Light gray smoke
► A brief chemical odor
This is completely normal.
Dust and Processing Residues
Even a properly packaged grill may have traces of:
► Cardboard dust
► Warehouse debris
► Fingerprints
► Polishing residues
These substances will burn off quickly during the first use.
Metal Treatment Compounds Vaporizing
Some BBQ grills are coated with a temporary rust inhibitor before shipping. When heated, these inhibitors evaporate and may produce a slight metallic or industrial odor. This does not indicate a defect in the material.
3. Corten Steel Seasoning Process
Initial Patina Formation at High Heat
Weathering steel is designed to form a stable, self-protective oxide layer—commonly referred to as a “rust layer.” Unlike the superficial rust found on ordinary low-carbon steel, this oxide layer is dense and strongly adherent, acting as a barrier that effectively slows further corrosion.
Upon initial exposure to high temperatures, the steel surface undergoes accelerated oxidation. The heat speeds up the chemical reaction between iron and oxygen, causing this protective layer to form sooner than it would under normal outdoor weathering conditions.
For this reason, the initial firing is not merely a cleaning step, but a controlled activation of the material’s long-term durability mechanism.
Initial Firing Accelerates Natural Weathering
Under normal ambient conditions, weathering steel may take weeks or months to show visible signs of weathering. However, the heat treatment during the initial firing process:
► Removes moisture and oils
► Activates surface oxidation sites
► Initiates the formation of a micro-layer of protective oxides
This process helps transform the grill from a “manufactured surface” into a fully functional, weathering-capable surface.
Understanding Smoke Types During Seasoning
The smoke produced during the first use of a grill is not always the same. Distinguishing between different types of smoke can help determine whether the process is proceeding normally:
► Light white/gray smoke → Burning of grease and residue (normal)
► Thin, bluish-gray smoke → Early oxidation and microparticles (normal)
► Thick, black smoke → Excess fat or contaminants present (requires close monitoring; extend seasoning time)
Recognizing these differences helps avoid unnecessary worry while ensuring a proper seasoning process.
Why Seasoning Affects Long-Term Performance
Properly performing the initial seasoning process can:
► Stabilize the surface
► Reduce odors during future use
► Ensure the formation of an even patina
► Prevent uneven oxidation spots
Skipping or rushing this step may result in:
► Uneven coloring
► Persistent odors during future use
► Uneven surface aging
4. Step-by-Step First Burn Instructions
Step 1: Prepare the Grill Before Ignition
Before lighting the fire:
► Remove all packaging materials
► Check the firebox for any debris
► Wipe away visible dust with a dry cloth
This helps reduce unnecessary smoke during the burning process.
Step 2: Perform a controlled dry burn (30–60 minutes)
Set the grill temperature to 300–400°F (150–200°C) and run it for 30–60 minutes.
Why is this temperature range critical:
► The temperature is high enough to burn off residues
► The temperature is low enough to avoid thermal stress
► It helps achieve a gradual and uniform break-in
Avoid extremely high temperatures during the first cycle, as rapid expansion can cause stress on new welds or joints.
Step 3: Maintain Adequate Airflow and Ventilation
Airflow plays a critical role in the following areas:
► Efficiently burning off residues
► Dispelling smoke
► Preventing the buildup of harmful fumes
Ensure that:
► Ventilation openings are fully open
► The barbecue grill is placed in an open area
► Wind direction blows smoke away from buildings
Step 4: Observe Changes in Smoke
Observe changes in the smoke:
► Initially thick → Normal
► Gradually decreases → Process is correct
► Remains unchanged → Extend searing time
This real-time feedback helps determine whether the process is complete.
Step 5: Perform a Second Searing
After cooling, perform a second searing for 15–30 minutes.
This step:
► Removes residues
► Further stabilizes the surface
► Ensures compliance with food safety standards
5. What to Expect During First Use
Smoke Behavior: A Predictable Burn-Off Curve
When you first light your outdoor grill, it will go through a gradual smoking process. This isn’t random—it follows a fairly predictable pattern closely related to temperature and the evaporation of residue:
► 0–10 minutes: Visible smoke begins to appear as surface grease reaches its vaporization temperature
► 10–30 minutes: Smoke peaks as deep-seated residue burns
► 30–60 minutes: Smoke gradually decreases as most contaminants are removed
Understanding this process helps prevent unnecessary worry. If the smoke gradually decreases over time, it indicates that the grill is functioning normally.
Color Changes on the Steel Surface
Weathering steel undergoes immediate visual changes when heated. You may observe:
► Thermal discoloration (blue/purple tones) caused by high-temperature oxidation
► Deepening of color to a matte gray or brown hue
► Uneven formation of early rust spots
This is not cosmetic damage—it is the formation of a protective oxide layer. Over time, exposure to moisture and air will gradually even out the color.
Odor Characteristics: Normal vs. Unusual Odors
The odor upon first use may vary depending on the manufacturing process and storage conditions. Common odor characteristics include:
► Tar-like odor → Evaporation of the protective coating
► Metallic odor → Reaction between heated steel and oxygen
► Mild chemical odor → Trace amounts of industrial residues
These odors typically:
► Are strongest during the initial burning phase
► Diminish significantly after 30–60 minutes
► Become barely noticeable after the second use
Residue Formation After Cooling
Once the Corten grill has cooled, the following may typically appear:
► Fine black or gray powder
► Slight ash-like residue
► A thin surface film
These are byproducts of burned grease and particles. Wipe them clean before using the grill again.
Acoustic and Thermal Characteristics
You may hear:
► A slight clicking or clinking sound
► A faint sound of expansion
These sounds are caused by the thermal expansion of the steel and are completely normal during the initial heating cycle.
6. When Smoke / Smell Is NOT Normal
Persistent Dense Black Smoke
Although a small amount of black smoke may appear at the start of combustion, it should not remain thick and persistent throughout the entire combustion process.
If thick black smoke:
► Has not decreased after 60 minutes
► Persists during the second combustion
This may indicate:
► Excess fuel
► Incomplete combustion due to restricted airflow
► Contaminants inside the combustion chamber
Sharp, Acrid, or Synthetic Odors
A mild metallic odor is normal. However, a strong, pungent odor—especially one resembling:
► Burning plastic
► Chemical solvents
► Rubber
is not normal and may indicate:
► Residual packaging materials
► Foreign matter introduced during storage
► Contamination during manufacturing or transportation
Viscous or Asphaltic Residue
After cooling, the surface should feel dry to the touch. If you observe:
► Viscous patches
► Shiny, asphaltic residue
► An uneven film that is difficult to wipe off
This indicates incomplete sintering or contamination.
Surface Integrity Issues
Weathering steel should not exhibit:
► Peeling
► Bubbling
► Paint-like flaking
If such symptoms appear, they may indicate:
► Improper surface treatment
► Coating contamination (this typically does not occur with genuine weathering steel)
When to Report a Problem
You should contact the manufacturer if any of the following conditions occur:
► An unusual odor persists after 2–3 ignition attempts
► Heavy smoke continues without improvement
► Visible defects appear on the steel surface
Early diagnosis ensures that performance and safety are not compromised.
7. Safety During First Burn
Ventilation Is Critical
Smoke production is heavier during the first ignition than during normal use. Please ensure the following:
► Place the unit completely outdoors
► Ensure adequate airflow
► Keep it away from walls or enclosed structures
Poor ventilation can cause smoke to accumulate, increasing the risk of inhalation.
Beware of High-Temperature Areas
During the first ignition, temperatures may fluctuate as residue burns off. The exterior surface may become extremely hot to the touch.
Please maintain:
► A safe distance around the modern grill
► A safe distance from flammable materials (wood, fabric, plastic)
Supervision is Essential
Unlike regular cooking, the initial ignition must never be left unattended because:
► Unexpected flare-ups may occur
► Smoke levels may need to be monitored
► Airflow adjustments may be necessary
Safety Precautions for Users
To ensure safety:
► Do not lean directly over the grill
► Wear heat-resistant gloves when adjusting the vents
► Stand upwind whenever possible
Environmental Considerations
Wind direction affects:
► Smoke dispersion
► Flame behavior
► Heat accumulation
Position the grill so that smoke drifts away from living areas and neighbors.
8. After First Burn Care
Controlled Cooling: Protecting Structural Integrity
After the initial firing is complete, be sure to allow the BBQ grill to cool naturally and slowly. Rapid cooling (such as pouring water onto hot steel) can cause thermal shock, leading to:
► Slight warping of the surface
► Stress in welded joints
► Uneven early oxidation
Although weathering steel can withstand thermal cycling, controlled cooling helps maintain its dimensional stability, especially during the initial tempering phase.
Post-Seasoning Surface Restoration and Cleaning Procedures
Once the grill has cooled to ambient temperature, perform a light cleaning to remove combustion byproducts. Specific steps include:
► Wipe down interior surfaces with a dry or slightly damp cloth
► Use a brush to remove loose carbon residue from the grill
► Clear fine ash from the firebox
Avoid using chemical cleaners during this stage. The purpose of cleaning is not deep cleaning, but rather to remove loose contaminants that could affect the second preheating or initial cooking.
Understanding Residues
The following are normal occurrences:
► Fine black powder (carbonized oil residue)
► A thin layer of gray ash
► Slight discoloration in high-temperature areas
These signs indicate that the scorching process has been completed effectively. However, if the residue appears sticky or greasy, it may indicate incomplete scorching, and it is recommended to extend the duration of the second scorching.
Secondary Heating as a Stabilization Cycle
Secondary heating is not an optional step—it is a critical refinement stage in the seasoning process. An additional 15–30 minutes of heating over medium heat will:
► Eliminate any remaining volatile compounds
► Stabilize the initial oxidation protective layer
► Ensure the environment is free of odors
This step transitions the grill from its “factory-new” state to an operational state that meets food safety standards.
Surface Preparation Before First Use
Before placing food on the grill:
► Confirm that the cooking surface is free of visible residue
► Ensure that odors are minimal or completely gone
► Optional: Apply a thin layer of cooking oil to the grill (if applicable)
This provides a cleaner surface for food contact and enhances cooking performance.
9. Long-Term Prevention
Maintaining Clean Combustion Efficiency
Among the factors that determine the long-term performance of a barbecue grill, combustion quality is often the most overlooked. Incomplete combustion can lead to:
► Excessive smoke
► Soot buildup
► Unpleasant odors
To maintain efficient combustion:
► Use dry, high-quality fuel (for wood-fired grills)
► Ensure vents are unobstructed
► Avoid overloading the firebox
Efficient combustion reduces residue buildup and extends maintenance intervals.
Routine Cleaning and Maintenance Schedule
Consistent, simple daily maintenance can prevent major issues. After each use:
► Clear out the ashes once the grill has cooled completely
► Clean the grates
► Check the airflow passages
Ashes are hygroscopic (they absorb moisture), which can lead to:
► Trapping moisture inside the grill
► Accelerating localized corrosion
► Blocking airflow over time
Perform Regular High-Temperature “Self-Cleaning” Burn-Ins
Occasional high-temperature burn-ins (similar to the initial seasoning process) help to:
► Burn off accumulated grease
► Remove organic residues
► Restore internal cleanliness
This procedure is particularly effective after cooking high-fat foods multiple times.
Moisture Management and Environmental Exposure
Weathering steel performs exceptionally well in cycles of wet and dry conditions, but prolonged exposure to damp environments can compromise its optimal performance. Please avoid:
► Water accumulation inside the firebox
► Accumulation of debris that traps moisture
► Prolonged exposure to rain without proper drainage
Using a breathable cover or placing the grill in a partially shaded area helps maintain ideal conditions and promotes the formation of a stable rust layer.
Annual Inspections and Preventive Maintenance
Conduct a more detailed inspection at least once a year:
► Check welded joints for signs of stress
► Ensure that vents and drainage holes are unobstructed
► Check for any unusual signs of corrosion
This proactive maintenance approach helps identify issues before they affect performance or safety.
Management of the Weathering Layer Over Time
The appearance of weathering steel continues to change over time. As time passes:
► The color will gradually deepen from orange to dark brown
► The surface will become more uniform
► The protective layer will stabilize
Unless addressing a specific issue, avoid sanding or vigorously cleaning the surface, as this may reset the rust layer formation process.
Conclusion: Fire up Your Corten Grill
If your new Corten grill smokes or smells during first use, this is almost always a normal seasoning process rather than a defect. Once seasoned correctly, your Corten grill can provide decades of reliable outdoor cooking performance with minimal maintenance.
Enjoy the process—the first burn is simply the beginning of your grill’s long service life.
FAQ About Corten BBQ Grills
Q1: Can I Cook Immediately After the First Burn?
We strongly recommend waiting until at least two preheating cycles are complete before use. The first preheating cycle removes most residues, while the second ensures:
► Complete vaporization of remaining compounds
► Stabilization of the surface
► A safe cooking environment
Q2: How Long Does It Take for the BBQ Grill to Become Completely Odor-Free?
The process for most grills is as follows:
► First preheat: Noticeable smoke and odors
► Second preheat: Significant reduction in odors
► Third use: Almost no odor or completely odor-free
Environmental factors such as humidity and airflow may slightly affect the duration of this process.
Q3: Is Black Residue After First Burn Harmful?
The black residue is a byproduct of fat burning and carbon buildup. While it does not damage the grill’s structure, you should:
► Remove it before cooking
► Avoid contact with food
Proper cleaning ensures food safety and prevents food from absorbing unwanted odors.
Q4: Why Does the Grill Change Color Over Time?
Weathering steel is designed to evolve. Its color changes result from:
► Continuous oxidation
► Exposure to the elements
► Thermal cycling during use
This transformation enhances both its aesthetic appeal and corrosion resistance.
Q5: Will the Barbecue Grill Stop Smoking Completely?
After proper seasoning, heavy smoking should cease. However:
► Minor smoke during cooking is normal
► Occasional smoke during high-temperature cleaning and burning is expected
► Persistent heavy smoking typically indicates a maintenance or fuel issue, not a material defect.
Q6: What Is the Ideal First-Use Timeline?
Follow the proper preheating procedure:
► First ignition: 30–60 minutes (to remove major residues)
► Allow to cool naturally
► Wipe down the surface
► Second ignition: 15–30 minutes (to stabilize)
► Final cooling
► Ready to start cooking
Q7: Does Weather Affect the First Burn Process?
Yes. The following factors:
► High humidity
► Low temperatures
► Poor air circulation
can all affect combustion efficiency and smoke dispersion. In such cases, extending the burn time appropriately may improve results.
