Your cast iron skillet smokes because it’s too hot, has excess oil buildup, or you’re using oils with low smoke points. Most cast iron smoking problems stem from temperature control issues combined with improper oil selection. The good news? These issues are straightforward to fix once you understand what’s happening in your pan.
Your cast iron smoking problem has a solution. Start by lowering your cooking temperature and switching to high smoke point oils—these two changes alone eliminate smoking for most people. Clean thoroughly after each use and apply only minimal oil. With consistent proper technique, your cast iron will develop excellent seasoning that cooks beautifully without filling your kitchen with smoke.
Cast iron retains heat far better than other cookware materials. This exceptional heat retention—while perfect for searing—means your skillet continues getting hotter even after you’ve achieved the right cooking temperature. When oils exceed their smoke point, they break down and produce visible smoke that fills your kitchen.
This guide covers why your cast iron produces so much smoke and provides actionable solutions to stop it.
Why Does My Cast Iron Skillet Smoke So Much? The Main Culprits
Your cast iron skillet smokes excessively due to six primary causes: excessive heat, old oil buildup, wrong oil selection, too much oil, deteriorating seasoning, or burning food residue.
Your Skillet Is Too Hot
High heat is the number one reason cast iron skillets smoke. Cast iron’s superior heat retention means it doesn’t need the same high temperatures you’d use with stainless steel or aluminum pans.
Why temperature matters:
Cast iron continues absorbing heat even on medium settings
The pan stays hot longer than you expect
Oils reach their smoke point faster on overheated surfaces
Most home cooking needs only medium or medium-low heat
Many cooks make the mistake of cranking the burner to high. This approach works with thinner pans that heat quickly and cool quickly. Cast iron behaves differently. The thick metal absorbs heat slowly but releases it just as slowly, creating a reservoir of thermal energy.
Old or Excess Oil Buildup on Your Cast Iron
Layers of old seasoning and residual cooking oils accumulate over time. When these layers get too thick or uneven, they carbonize and produce smoke during cooking.
Common buildup issues:
Thick, gummy residue from using too much oil during seasoning
Rancid oils that have oxidized during storage
Uneven patches where seasoning has pooled and hardened
Sticky surfaces that indicate improper seasoning technique
This buildup smoke differently than fresh cooking oil. The smoke often appears immediately when you place the pan on heat, before adding any food. A brownish or dark smoke with a slightly acrid smell typically indicates old oil burning off.
Different oils tolerate different temperatures before smoking. Using butter or extra virgin olive oil in a screaming-hot cast iron pan guarantees smoke.
Smoke Points of Common Cooking Oils:
Oil Type
Smoke Point
Best For
Avocado Oil
520°F
High-heat searing, frying
Refined Safflower Oil
510°F
High-heat cooking, seasoning
Grapeseed Oil
420°F
Medium-high cooking
Canola Oil
400°F
General cooking
Vegetable Oil
400°F
General cooking
Extra Virgin Olive Oil
350°F
Low-medium heat only
Butter
300°F
Low heat, finishing
Flaxseed Oil
225°F
Cold use only, not cooking
The smoke point represents the temperature at which oil breaks down and produces visible smoke. Exceeding this temperature creates not just smoke but also unpleasant flavors and potentially harmful compounds.
Using Too Much Oil or Fat
A common misconception is that cast iron needs lots of oil. Excess oil pools in the pan, heats unevenly, and smokes more readily than a thin coating.
How much oil you actually need:
For sautéing: 1-2 teaspoons for a 10-inch skillet
For shallow frying: Enough to come halfway up the food
For searing: Just enough to coat the surface when wiped with a paper towel
Think of oiling cast iron like moisturizing your skin. You want a thin, even layer that absorbs and protects—not puddles sitting on the surface. Too much oil has nowhere to go except up in smoke when heated.
Your Seasoning Is Breaking Down
Cast iron seasoning consists of polymerized oil bonded to the metal surface. When this protective layer deteriorates, the exposed iron heats unevenly and causes the remaining seasoning patches to smoke.
Signs of seasoning breakdown:
Dull, gray patches appearing on the cooking surface
Food sticking where it previously didn’t
Flaking or peeling spots
Rust formation in worn areas
Seasoning breakdown occurs from acidic foods, aggressive scrubbing, or simply wear over time. The degraded seasoning smokes because it’s no longer properly bonded to the iron. These loose particles burn at lower temperatures than intact seasoning.
Food Residue and Debris Are Burning
Leftover food particles from previous cooking sessions burn and smoke when you heat the pan again. Even tiny bits of stuck-on food create disproportionate amounts of smoke.
A clean cast iron skillet should look dark and relatively smooth. If you see brown or black crusty bits, those will burn and smoke during your next cooking session.
How to Stop Your Cast Iron Skillet From Smoking
Stop your cast iron from smoking by lowering your cooking temperature, choosing high smoke point oils, using less oil, cleaning properly, and maintaining good seasoning.
Solution 1: Lower Your Cooking Temperature
Start with medium or medium-low heat for almost all cast iron cooking. The pan needs 5-10 minutes to preheat properly, but this gradual approach prevents overshooting the target temperature.
The proper preheating method:
Place your cast iron on a cold burner
Turn heat to medium or medium-low
Wait 5 minutes for 10-inch skillets, 7-8 minutes for 12-inch
Test temperature by flicking water drops on the surface
If water immediately evaporates with a hiss, you’re ready
Temperature testing without a thermometer:
Too cold: Water pools and sits on the surface
Just right: Water beads and dances around the pan (the “mercury ball” effect)
Too hot: Water explodes into steam instantly
Most recipes calling for “high heat” in regular pans need only medium heat in cast iron. The thermal mass does the heavy lifting. For searing steaks or achieving a hard sear on proteins, medium-high occasionally makes sense. But even then, watch for smoke and adjust down if needed.
Solution 2: Choose High Smoke Point Oils
Match your cooking oil to your cooking temperature. High-heat cooking demands high smoke point oils.
Best oils for cast iron at different temperatures:
Save your expensive extra virgin olive oil for dressings and low-heat applications. When cooking above medium heat, refined oils with neutral flavors and high smoke points work better and won’t fill your kitchen with smoke.
Solution 3: Use Less Oil
Apply oil in thin, even coats rather than pouring directly into the pan. This technique dramatically reduces smoke while providing adequate lubrication.
The paper towel method:
Add 1/2 to 1 teaspoon of oil to your preheated pan
Use a folded paper towel held with tongs
Wipe the oil around the entire cooking surface
The pan should look glossy but not have visible oil pools
Add more only if food sticks during cooking
This minimal oil approach works because cast iron’s seasoning already provides non-stick properties. You’re supplementing the seasoning, not creating a swimming pool for your food.
For deep frying or shallow frying, you’ll obviously need more oil. But for everyday cooking—eggs, vegetables, pan-seared proteins—a teaspoon goes surprisingly far.
Solution 4: Clean Your Cast Iron Properly
Proper cleaning between uses prevents residue buildup that causes smoking. Your cast iron needs thorough cleaning, not just a quick wipe.
Step-by-step cleaning to prevent smoke:
Clean while still warm (not screaming hot)
Use hot water and a stiff brush or chain mail scrubber
Add a small amount of soap if needed (modern dish soap won’t harm seasoning)
Scrub away all food particles until the surface feels smooth
Dry completely with a towel immediately
Heat on the stove for 1-2 minutes to evaporate remaining moisture
Apply a micro-thin layer of oil while still warm
For stubborn residue:
Coarse salt + oil makes an effective scrubbing paste
Chain mail scrubbers remove stuck food without damaging seasoning
Plastic pan scrapers work for flat bottom cleaning
Bar Keeper’s Friend (used sparingly) tackles tough spots
The myth that you can’t use soap on cast iron is outdated. Modern dish soaps don’t contain lye like old-fashioned soaps did. A small squirt of Dawn won’t strip your seasoning. What will damage seasoning is leaving food residue to carbonize during the next cooking session.
Solution 5: Strip and Re-Season If Necessary
When buildup becomes excessive or seasoning is severely degraded, starting fresh solves persistent smoking issues.
When to strip and re-season:
Thick, gummy residue that won’t clean off
Extensive rust coverage
Severe flaking or peeling seasoning
Persistent smoking despite trying other solutions
Inherited or thrift store finds with unknown history
Basic re-seasoning overview:
Strip old seasoning using oven cleaner, electrolysis, or the self-cleaning oven method
Scrub down to bare metal
Dry thoroughly and apply thin coat of high smoke point oil
Wipe away excess until surface looks almost dry
Bake upside down at 450-500°F for 1 hour
Repeat seasoning 3-5 times for best results
A fresh seasoning gives you a clean slate. The process takes time but eliminates years of accumulated problems. Your properly re-seasoned cast iron will smoke far less during normal cooking.
Solution 6: Ensure Proper Ventilation
Good ventilation manages smoke even when you’re doing everything right. Some smoke during high-heat cooking is normal and expected.
Effective ventilation strategies:
Turn on your range hood before preheating
Open a window on the opposite side of the kitchen to create cross-ventilation
Use a box fan in a window to actively exhaust smoke
Close doors to other rooms to contain any smoke
Ventilation doesn’t prevent smoking, but it makes cast iron cooking more pleasant. Even professional chefs deal with smoke when searing proteins at high heat. The difference is commercial ventilation systems that remove it instantly.
Understanding Cast Iron Seasoning and Smoke
Cast iron seasoning is polymerized oil bonded to the metal surface through heat, creating a natural non-stick coating that can produce smoke when applied incorrectly or when it breaks down.
What Is Cast Iron Seasoning?
Seasoning forms when oil heats past its smoke point in a controlled environment. The heat causes the oil’s fatty acids to break down and reorganize into a hard, slick polymer layer bonded to the iron.
The polymerization process:
Oil heats beyond its smoke point (400°F+)
Fatty acid molecules break apart
These molecules reorganize and bond to the iron surface
Multiple thin layers create a durable, non-stick finish
This is why seasoning in the oven at 450-500°F works. You’re deliberately taking oil past its smoke point to trigger polymerization. The key difference between seasoning smoke and cooking smoke: seasoning smoke happens in a controlled process with minimal oil, while cooking smoke indicates a problem.
Why New Cast Iron Skillets Sometimes Smoke More
Factory pre-seasoning on new skillets varies in quality. Some manufacturers apply thick, uneven coats that smoke excessively until they’re worn down through use.
What to expect with new cast iron:
First 5-10 uses may produce more smoke than expected
Factory seasoning can smell odd when first heated
The surface improves as you cook and add your own seasoning layers
Breaking in new cast iron takes patience
Give your new skillet several cooking sessions before judging its performance. Each time you cook, you’re adding micro-layers of seasoning that improve the surface. The break-in period typically lasts 10-20 cooking sessions.
The Connection Between Seasoning and Smoking
Well-seasoned cast iron with thin, even layers smokes less than poorly seasoned pans with thick, uneven coating.
Good seasoning characteristics:
Smooth, hard surface that feels almost glassy
Even black or dark brown color across the pan
Natural sheen without stickiness
Food releases easily with minimal oil
Poor seasoning that causes smoke:
Sticky or tacky feeling when touched
Uneven coloring with thick patches
Flaking or peeling areas
Rough texture with visible buildup
Think of seasoning like paint on a car. Multiple thin coats create a better finish than one thick coat. Thin seasoning layers bond properly and don’t produce smoke. Thick globs of half-polymerized oil smoke at the slightest provocation.
Common Cast Iron Smoking Scenarios and Solutions
Cast iron smokes in specific situations that require targeted solutions beyond general advice.
Why Does My Cast Iron Smoke When Empty or Preheating?
Empty cast iron pans smoke during preheating because residual oils from previous seasoning or cooking sessions are burning off at high temperatures.
Causes of preheating smoke:
Oil residue left from the last cooking session
Over-oiling after cleaning
Heat set too high from the start
Old, rancid oil in the seasoning layers
Solutions:
Wipe the pan with a dry paper towel before heating to remove excess oil
Start with lower heat and increase gradually
Clean more thoroughly after each use
Re-season if smoke persists despite cleaning
Some preheating smoke is normal, especially if you oiled the pan after the last cleaning. But heavy smoke before you add food indicates too much residual oil or heat that’s too high.
Why Does My Cast Iron Skillet Smoke in the Oven?
Cast iron smokes in the oven when you’re seasoning it because you’re deliberately heating oil past its smoke point, or because oven temperature exceeds your cooking oil’s smoke point.
During seasoning:
Smoke is expected and normal
Peak smoke occurs 10-20 minutes into the seasoning cycle
Smoke should decrease as oil fully polymerizes
Proper ventilation is critical
During cooking:
You’ve used too much oil on the pan surface
Oven temperature is too high for the oil type used
Food drippings are burning on the pan or oven bottom
How to minimize oven smoking:
Use only a microscopic amount of oil when seasoning (wipe until the pan looks dry)
Choose oils rated above your oven temperature
Place a sheet pan on the rack below to catch drips
Open windows and run ventilation before starting
The key to smoke-free oven seasoning is using far less oil than you think necessary. After applying oil, wipe the pan aggressively. It should look like you didn’t oil it at all.
Why Does Cast Iron Smoke More Than Stainless Steel or Non-Stick?
Cast iron smokes more because it retains significantly more heat and has seasoning layers that can burn, unlike stainless steel or non-stick surfaces.
Material comparison:
Factor
Cast Iron
Stainless Steel
Non-Stick
Heat retention
Very high
Low-medium
Low
Smoke-producing coating
Yes (seasoning)
No
No
Thermal mass
High
Low-medium
Very low
Temperature control
Slow to adjust
Quick to adjust
Quick to adjust
Cast iron’s thick construction stores tremendous heat energy. When stainless steel cools down quickly after reducing burner heat, cast iron keeps climbing in temperature. This lag makes it easier to accidentally overheat cast iron past your oil’s smoke point.
The seasoning layer adds another smoke source that other pans lack. Stainless steel has bare metal—no coating to burn. Non-stick pans have synthetic coatings that don’t smoke (though they can release harmful fumes if grossly overheated).
Why Does My Cast Iron Smoke Even on Low Heat?
Cast iron that smokes on low heat has old oil buildup, rancid seasoning, or food debris that burns at temperatures below fresh oil’s smoke point.
Low-temperature smoking causes:
Carbonized food particles from inadequate cleaning
Scrub the pan thoroughly with hot water and a stiff brush
Use coarse salt as an abrasive if needed
Inspect closely for any stuck-on food or buildup
Re-season if the surface feels sticky or looks uneven
Low-heat smoking is abnormal and indicates a dirty pan rather than a temperature control issue. A clean, well-maintained cast iron skillet should not smoke at temperatures below 350°F.
Preventing Your Cast Iron From Smoking: Best Practices
Prevent cast iron smoking through consistent maintenance, proper temperature control, smart oil selection, and regular seasoning upkeep.
Proper Cast Iron Maintenance Routine
A simple after-cooking routine prevents the buildup that causes smoking.
After every use:
Clean while warm with hot water and brush
Dry thoroughly with a towel
Heat on stove for 1-2 minutes to eliminate moisture
Rub with a tiny amount of oil (optional for frequent use)
Store in a dry place
Monthly maintenance:
Inspect for wear spots or seasoning damage
Do a stovetop seasoning session if needed (heat with thin oil layer for 10 minutes)
Check for any rust spots and address immediately
Storage tips:
Store with a paper towel inside to absorb any moisture
Don’t stack directly on other cookware (scratches seasoning)
Keep in a dry cabinet or hang on a wall rack
Never put away even slightly damp
Consistency matters more than perfection. A cast iron pan used and maintained regularly develops better seasoning and smokes less than one that sits unused for months at a time.
Temperature Control Mastery
Learning your specific stove and cast iron combination eliminates most smoking issues.
Getting to know your setup:
Electric coils heat differently than gas flames or induction
Burner size affects how evenly the pan heats
Different sized skillets need different heat settings
Your stove’s “medium” might be another stove’s “medium-high”
The patience approach:
Minute 0-2: Cold pan on medium heat, no visible changes
Minute 2-5: Pan warming, you can feel heat radiating
Minute 5-8: Pan hot enough for the water test
Minute 8+: Fully preheated and ready to cook
Rushing this process by cranking the heat leads to smoke. Cast iron rewards patience. The gradual preheat distributes heat evenly across the entire cooking surface and prevents hot spots that burn oil.
Smart Oil Selection and Application
Build a practical collection of oils for different cast iron cooking scenarios.
Your cast iron oil toolkit:
For high-heat cooking:
Avocado oil (520°F smoke point) – expensive but worth it for searing
Crisco or vegetable shortening – traditional choice that works well
For finishing:
Butter – adds flavor after primary cooking
Extra virgin olive oil – for Mediterranean dishes at lower heat
Application technique:
Always use less than you think you need
Apply to a hot pan (not cold)
Spread with a paper towel for even coating
Add more during cooking only if food sticks
Switching to high smoke point oils for high-heat cooking might single-handedly eliminate your smoking problem.
Building and Maintaining Quality Seasoning
Good seasoning develops gradually through regular cooking and occasional intentional seasoning sessions.
Seasoning-building foods:
Fatty meats (bacon, sausage)
Shallow-fried foods
Sautéed vegetables with oil
Cornbread and other baked goods
Foods that strip seasoning:
Tomato-based sauces (acidic)
Wine or vinegar-heavy dishes
Citrus-based recipes
Long-simmered watery dishes
Stovetop seasoning touch-ups:
Clean and dry the pan completely
Apply a very thin coat of high smoke point oil
Heat on medium for 10 minutes until the pan smokes lightly
Let cool and wipe away any excess
You don’t need to season after every use. But if you notice food sticking more than usual or dull patches appearing, a quick stovetop seasoning session restores the surface. This 10-minute maintenance prevents bigger problems and reduces future smoking.
Troubleshooting: My Cast Iron Still Smokes
If your cast iron continues smoking despite following standard advice, deeper issues require investigation.
Checking for Hidden Issues
Systematic inspection reveals problems you might overlook during normal use.
Detailed inspection checklist:
Visual examination:
Hold the pan at an angle under good light
Look for shiny patches (over-oiled) or dull gray areas (worn seasoning)
Check for tiny food particles trapped in the cooking surface texture
Inspect the underside and handle for crusty buildup
Touch test:
Run your fingers across the cooking surface
Properly seasoned cast iron feels smooth and slightly slick
Sticky or tacky areas indicate seasoning problems
Rough patches suggest buildup or damage
Smell test:
Old, rancid oil has a distinctive unpleasant odor
Sniff the pan when cold
Rancid fat smells stale, like old crayons or paint
Heat distribution test:
Preheat the pan on medium for 5 minutes
Sprinkle a thin layer of flour across the surface
Flour should brown evenly
Hot spots that darken faster indicate uneven heating (not a smoking cause but worth noting)
When Smoking Is Normal (and When It’s Not)
Some smoke during cast iron cooking is acceptable. Excessive smoke signals problems.
Normal, acceptable smoke:
Brief wisps when searing a steak at high heat
Initial smoke when seasoning in the oven
Light smoke when cooking fatty meats like bacon
Occasional smoke from food particles (not pan itself)
Abnormal smoke requiring action:
Heavy smoke immediately upon heating an empty pan
Continuous thick smoke during normal cooking
Black or gray smoke (rather than white/bluish)
Smoke accompanied by acrid, unpleasant smells
Any smoke when cooking at medium-low heat
Health and safety considerations:
Smoke from burning oil creates indoor air pollution
Repeatedly breathing cooking smoke can irritate lungs
Damaged non-stick coatings release harmful fumes (cast iron doesn’t have this issue)
Excessive smoke can trigger smoke alarms
If your cast iron produces concerning amounts of smoke during normal use, address it rather than accepting it as inevitable.
Starting Fresh: Complete Restoration
When other solutions fail, stripping and re-seasoning gives your cast iron a fresh start.
When restoration makes sense:
You’ve tried everything else
The pan has unknown history (thrift store, inherited)
Seasoning is severely damaged or uneven
Persistent smoking despite cleaning and proper technique
Quick restoration overview:
Stripping methods:
Oven cleaner method: Spray with lye-based cleaner, seal in plastic bag for 24 hours, scrub
Self-cleaning oven: Place pan in self-cleaning cycle (controversial, can crack vintage pans)
Electrolysis: Most thorough but requires setup (battery charger, washing soda, container)
Vinegar soak: For rust removal (not full seasoning strip)
After stripping:
Scrub down to bare gray metal
Rinse and dry immediately (bare iron rusts quickly)
Apply first seasoning coat within minutes of drying
Follow oven seasoning method with thin oil layers
Repeat 4-6 times for durable finish
Complete restoration takes time—expect to spend a full day between stripping and multiple seasoning rounds. But you’ll end up with a pan that performs like new and doesn’t smoke during normal cooking.
FAQ: Cast Iron Skillet Smoking Questions
Is it dangerous when my cast iron skillet smokes?
Cast iron skillet smoke is generally not dangerous in well-ventilated spaces, but breathing smoke from burning oil repeatedly can irritate your respiratory system and trigger smoke alarms.
Health considerations:
Burning oil produces particulate matter and volatile compounds
Short-term exposure causes minor irritation for most people
People with asthma or respiratory conditions should minimize exposure
Proper ventilation reduces risks significantly
When to be concerned:
Daily exposure to heavy smoke
Cooking in poorly ventilated spaces
Pre-existing respiratory conditions
Smoke that’s black or has chemical smells
Cast iron itself poses no danger. The smoke comes from oils breaking down at high temperatures. Good ventilation and proper technique eliminate most smoke, making the health concern moot.
Can I use my cast iron if it smokes?
You can use your cast iron skillet even if it smokes, but you should address the underlying cause for better cooking results and less kitchen smoke.
Short-term workarounds:
Open windows and turn on ventilation
Lower the heat immediately
Use less oil for the current cooking session
Cook outdoors on a grill if smoke is excessive
Impact on food:
Smoke itself doesn’t ruin food
However, oil that’s smoking has exceeded its smoke point and may impart bitter flavors
Food cooked in smoking oil can taste burnt or acrid
The pan’s seasoning won’t improve if it’s constantly smoking
Think of a smoking pan as a warning light on your dashboard. You can keep driving, but you should probably address the issue before it gets worse.
How do I know if my cast iron seasoning is causing the smoke?
Your cast iron seasoning is causing smoke if the pan produces heavy smoke when empty during preheating, feels sticky or tacky when cold, or has visible thick, uneven patches.
Diagnostic tests:
The empty pan test:
Heat the empty pan on medium for 5 minutes
If it smokes before reaching cooking temperature, the seasoning is likely the culprit
Fresh cooking oil doesn’t smoke until 350°F+ (depending on type)
The touch test:
Properly seasoned cast iron feels smooth and dry
Problematic seasoning feels sticky, tacky, or gummy
This stickiness comes from unpolymerized oil that will smoke when heated
Visual inspection:
Good seasoning appears uniform in color (black or dark brown)
Problem areas show thick patches, drips, or pooled oil
If these tests point to seasoning problems, strip and re-season the pan or do several stovetop seasoning sessions to even out the surface.
What temperature should I cook with cast iron to avoid smoking?
Cook with cast iron at medium or medium-low heat (approximately 300-375°F surface temperature) to avoid smoking, which is sufficient for most cooking tasks due to cast iron’s superior heat retention.
Temperature guidelines by cooking method:
Cooking Method
Heat Setting
Approximate Temp
Recommended Oil
Eggs, pancakes
Low-medium
250-300°F
Butter, any oil
Sautéing vegetables
Medium
300-350°F
Canola, vegetable
Pan-frying chicken
Medium
325-375°F
Canola, peanut
Searing steak
Medium-high
400-450°F
Avocado, safflower
Stir-frying
Medium-high
400-450°F
Peanut, grapeseed
Why lower heat works:
Cast iron distributes heat evenly across the surface
The thermal mass maintains stable temperatures
Food browns properly even at lower settings
Lower heat gives you more control and prevents burning
Start lower than you think necessary. You can always increase heat if food isn’t browning. You can’t undo an overheated pan that’s already smoking.
Will my cast iron stop smoking over time?
Your cast iron will stop smoking over time as you build better seasoning through regular use and maintain proper cooking techniques, typically within 10-20 cooking sessions.
What to expect:
First 5 uses:
Most smoke as you’re establishing technique
Factory seasoning may burn off and get replaced
Surface gradually becomes more non-stick
Uses 5-15:
Noticeable improvement in performance
Less smoke if you’re using proper temperature and oil
Seasoning becomes darker and more uniform
Uses 15+:
Well-established seasoning with minimal smoking
Pan performs reliably with proper technique
Only smokes if you overheat or use wrong oils
Factors that speed improvement:
Cooking fatty foods (bacon, sausage)
Consistent use (several times per week)
Proper cleaning and maintenance after each use
Avoiding acidic foods during the break-in period
What won’t improve over time:
Smoking from excess heat (technique issue, not pan issue)
Using low smoke point oils inappropriately
Poor cleaning that leaves residue
Cast iron improves with use, but you still need proper technique. A well-seasoned pan with poor technique will still smoke. A newer pan with good technique won’t smoke much at all.
