Cast Iron Seasoning: What the Side-by-Side Oil Tests Actually Showed

20 YouTube videos analyzed · 15 channels · 4h 3m of video

Cast Iron Seasoning: What the Side-by-Side Oil Tests Actually Showed

Key Takeaways

• Flaxseed oil flakes and cracks over time. Despite marketing hype from a viral 2010 blog post, multiple real-world tests document that flaxseed-seasoned pans develop brittle, peeling coatings within months to a couple of years of use, requiring re-seasoning. This brittleness is a direct result of flaxseed's extreme polymerization—it hardens too aggressively Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 01:00, What's The BEST OIL FOR CAST IRON SEASONING? IT Is NOT Flaxseed Oil! @ 08:28, Don't Use Flaxseed Oil! Best Methods and Oils to Season Carbon Steel @ 01:01.

• High smoke point oils (grapeseed, sunflower, avocado) outperform low smoke point oils. According to Dr. Zach Hudson, a polymer scientist, unsaturated seed oils with higher smoke points create more durable seasoning than flaxseed's 225°F smoke point. Polymerization happens well below the smoke point (around 330–350°F), so reaching or exceeding smoke point actually degrades the oil and risks brittle, carbonized layers The Truth About Seasoning Cast Iron (According to Science) @ 05:06, NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 05:05.

• Oil fiber content matters more than oil type. Refined oils from any category—vegetable, canola, grapeseed—produce consistent results because they lack the fiber particles that create stickiness and poor adhesion. Cold-pressed and organic oils trap fiber and flaxseed oil vendors often deliver inconsistent products with no quality standard What is the best Seasoning Oil for Cast Iron and Carbon Steel Cookware @ 04:05, Don't Use Flaxseed Oil! Best Methods and Oils to Season Carbon Steel @ 01:01.

• Cooking builds seasoning better than repeated oven seasoning. Side-by-side egg tests show that even one or two initial oven coatings followed by regular cooking produces non-stick results equal to or better than six oven cycles with flaxseed. Continuous use and cooking fat accumulation create a more resilient, self-repairing seasoning layer Cast Iron Skillet Seasoning - A Detailed How-To Video @ 30:45, Seasoning Cast Iron (Flaxseed vs. Old School methods) @ 04:05.

• Temperature control, not smoke point achievement, is the seasoning goal. Polymerization occurs below smoke point with long heating duration. Reaching visible smoke creates carbon buildup and accelerates flaking. The industry standard (including Lodge and Field) aims for 350–450°F oven temperatures with refined oils, not flaxseed's low-heat workaround NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 06:06, Cast Iron Skillet Seasoning - A Detailed How-To Video @ 24:39.

Executive Summary

The flaxseed oil myth—amplified by a 2010 metallurgist blog post and embraced by boutique cookware marketers—promised a superior, dishwasher-proof seasoning layer. Actual side-by-side tests across twenty sources show the opposite: flaxseed produces a glossy but brittle finish that flakes within months, while refined seed oils (grapeseed, sunflower, canola) at 25°F above smoke point create durable, smooth seasoning that improves with regular cooking. The key distinction is fiber (not oil type) and polymerization temperature (not reaching smoke point). Mass-market oils work as well as premium boutique blends because chemistry, not price, determines seasoning durability.

Flaxseed Oil's Brittleness Problem: Real-World Evidence

The central claim of the flaxseed oil movement—that cold-pressed flaxseed creates the "hardest, most durable, and most nonstick surfaces"—rests on 2010 blog analysis by Sheryl Canter (a software engineer with degrees in psychology and fine arts, not metallurgy as some claim) Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 02:01. Subsequent real-world testing contradicts this.

After six seasoning cycles with pure flaxseed oil, a cast iron pan developed a visible satin finish that performed adequately for frying eggs. However, when tested with acidic foods (boiled red wine), the seasoning stripped away entirely—no different from standard oil seasoning Seasoning Cast Iron (Flaxseed vs. Old School methods) @ 06:07. More critically, multiple cooks report that flaxseed-seasoned pans begin flaking within a couple of years, requiring complete re-seasoning Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 01:00, What's The BEST OIL FOR CAST IRON SEASONING? IT Is NOT Flaxseed Oil! @ 09:30.

The brittleness stems from flaxseed's extreme polymerization. Dr. Zach Hudson (polymer scientist, University of British Columbia) confirmed that flaxseed's very high alpha-linolenic acid (ALA) content—approximately six times that of canola—causes it to cross-link so aggressively that the resulting polymer becomes rigid and prone to cracking under thermal stress and metal-spatula use The Truth About Seasoning Cast Iron (According to Science) @ 06:08. Field Company and Lodge—manufacturers with decades of seasoning expertise—have both moved away from flaxseed, instead using refined seed oil blends with controlled ALA levels that create durable, flexible coatings NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 08:08.

The Fiber Myth: Why "Refined" Beats "Cold-Pressed"

One of the most misunderstood aspects of oil seasoning is the relationship between smoke point and seasoning quality. Sellers of premium oils exploit this confusion: they market cold-pressed, organic, unrefined oils as superior while labeling the smoke point (the temperature at which oil begins to smoke) as a target to hit during seasoning.

The reality is the opposite. What consumers call "smoke point" is actually the combustion point of oil fiber—the organic particles (pulp, skin fragments) left in unrefined oils. A refined olive oil with fiber removed has the same molecular smoke point as expensive, first-pressed variants, but the fibers burn off at a lower temperature, making the oil appear to have a "lower smoke point" What is the best Seasoning Oil for Cast Iron and Carbon Steel Cookware @ 04:05.

When seasoning cast iron, fiber creates sticky, poorly adhering layers because those particles don't polymerize; they char. Consequently, cheap refined vegetable oil, canola, or grapeseed from a mass-market retailer produces superior seasoning to expensive, artisanal cold-pressed versions of the same oils What is the best Seasoning Oil for Cast Iron and Carbon Steel Cookware @ 05:06. A $3 tin of Crisco polymerizes and bonds identically to a $20 boutique blend—the iron chemistry is identical The Seasoning Oil Scam (STOP WASTING MONEY) @ 03:04.

Flaxseed compounds this problem: boutique flaxseed vendors cannot guarantee consistency. One bottle may be cold-pressed and shelf-stable, another refrigerated and nearly oxidized. Some contain vitamin E or other additives marketed as "preservatives" that interfere with polymerization Cast Iron Skillet Seasoning - A Detailed How-To Video @ 07:08, Don't Use Flaxseed Oil! Best Methods and Oils to Season Carbon Steel @ 01:01. By contrast, a gallon of Wesson canola or Crisco shortening is identical whether you buy it in Miami or Maine, ensuring reproducible results Don't Use Flaxseed Oil! Best Methods and Oils to Season Carbon Steel @ 02:02.

Polymerization Below Smoke Point: The Science That Overturns the "Smoke Point = Seasoning" Rule

A pervasive myth holds that to season cast iron, you must heat oil to or past its smoke point. The flaxseed campaign leaned on this: proponents claimed flaxseed's low 225°F smoke point made it "foolproof" because even a weak oven would reach that threshold and trigger polymerization.

Actual polymer chemistry proves the opposite. Dr. Zach Hudson confirmed that polymerization—the cross-linking of oil molecules into a plastic-like polymer—occurs at temperatures well below the smoke point, often 50–100°F lower. If an oil's smoke point is 425°F, polymerization may begin at 330°F and proceed faster at higher temperatures without ever reaching smoke NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 05:05.

Reaching visible smoke (i.e., burning oil) creates carbon buildup, which is desirable for aesthetics but undesirable for durability. Carbon layers are brittle and flake; polymerized oil layers are flexible and self-repairing through continued cooking. This is why the gold standard is 350–450°F in an oven for 30–60 minutes—hot enough to drive polymerization but cool enough to avoid aggressive carbonization The Truth About Seasoning Cast Iron (According to Science) @ 09:23, NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 06:06.

Flaxseed's low smoke point became a liability rather than an asset: its extreme reactivity causes it to char and over-polymerize at standard oven temperatures, resulting in a hard but brittle layer prone to cracking NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 08:08.

Side-by-Side Cook Tests: Grapeseed and Flaxseed Perform Identically (Then Flaxseed Fails)

The most direct evidence comes from cooks who seasoned two identical cast iron pans—one with flaxseed, one with grapeseed—using the same oven process (500°F for one hour, repeated six times). After seasoning, both pans cooked eggs with similar results: minimal sticking, good release Cast Iron Skillet Seasoning - A Detailed How-To Video @ 26:40, Cast Iron Skillet Seasoning - A Detailed How-To Video @ 30:45.

The difference emerged weeks later. The grapeseed-seasoned pan continued to improve with regular cooking. The flaxseed pan began to show hairline cracks, and after a few months of acidic or high-heat cooking, the seasoning peeled in flakes Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 01:00. A second independent test produced identical findings: flaxseed and grapeseed showed no functional difference immediately post-seasoning, but only flaxseed developed the characteristic brittleness Seasoning Cast Iron (Flaxseed vs. Old School methods) @ 04:05, Seasoning Cast Iron (Flaxseed vs. Old School methods) @ 06:07.

These results align with manufacturing best practices. Field Company, a premium cast iron maker, confirmed they use three oven seasoning cycles with refined seed oils, not six cycles with flaxseed, because the result is more durable and flake-resistant NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 28:52.

The Myth of Six Cycles: Cooking Beats Repeated Oven Seasoning

The flaxseed protocol endorsed six to eight oven seasoning cycles (typically 1 hour per cycle at 500°F), consuming 6–8 hours of oven time and labor. Multiple tests show this is overkill and unnecessary.

A pan seasoned twice in the oven with refined grapeseed oil, then used for regular cooking (eggs, potatoes, vegetables), developed seasoning quality indistinguishable from a six-cycle flaxseed pan within a week Cast Iron Skillet Seasoning - A Detailed How-To Video @ 26:40. The reason: each time you cook with fat (butter, oil, meat drippings), you add a thin polymerized layer of seasoning. The heat, metal contact, and fat create the same polymerization reaction as the oven NO SMOKE NEEDED. The ultimate guide to oven and stove top seasoning without smoke @ 27:52.

One source summarized the consensus from lodge and manufacturer testing: two oven coats followed by regular cooking produces optimal results faster than six oven coats followed by storage Cast Iron Skillet Seasoning - A Detailed How-To Video @ 29:44. This inverts the flaxseed recommendation, which discouraged cooking during the initial seasoning phase and instead prescribed repetitive oven cycles.

The practical implication: new cast iron owners should apply one or two oven seasons with inexpensive refined oil (grapeseed, canola, vegetable), then start cooking immediately. Cooking with fat—sautéing, frying, roasting—builds seasoning 10 times faster than oven alone.

Recommended Oils: The Consensus Hierarchy

Across all sources, a clear ranking emerges:

Flaxseed appears universally in the "avoid" category, not because it fails to create initial seasoning, but because that seasoning degrades faster than alternatives and costs 4–10 times more What's The BEST OIL FOR CAST IRON SEASONING? IT Is NOT Flaxseed Oil! @ 08:28, The Seasoning Oil Scam (STOP WASTING MONEY) @ 04:05.

Lodge pre-seasons with refined vegetable or canola; they do not use flaxseed What's The BEST OIL FOR CAST IRON SEASONING? IT Is NOT Flaxseed Oil! @ 04:11. This choice by the largest cast iron manufacturer is revealing: if flaxseed truly produced superior seasoning, manufacturers would use it. Instead, they optimize for cost-effectiveness and durability, both of which favor refined seed oils Don't Use Flaxseed Oil! Best Methods and Oils to Season Carbon Steel @ 06:11.

Why the Boutique Oil Myth Persists

The flaxseed narrative benefits multiple stakeholders:

1. Boutique sellers can charge $15–25 per bottle of flaxseed marketed as "artisan" or "superior," compared to $3 for generic Crisco The Seasoning Oil Scam (STOP WASTING MONEY) @ 02:03.

2. Conflicting advice online creates anxiety among newcomers, making them susceptible to premium brands claiming to solve a non-existent problem The Seasoning Oil Scam (STOP WASTING MONEY) @ 02:03.

3. The 2010 blog post, written by a non-expert and citing only proprietary testing, was never peer-reviewed or reproduced by independent labs. Yet it ranks highly in search results and has been cited by Cook's Illustrated and thousands of YouTube channels, creating false authority Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 03:02.

4. Cast iron enthusiasts who invested in flaxseed emotionally defend their choice, creating survivor bias: "My flaxseed pan still works," without comparing directly to cheaper alternatives Calling BS On This Cast Iron Conspiracy Theory (Flaxseed Oil Seasoning) @ 06:04.

One commenter documented her experience: she spent two days running her oven at 500°F in the middle of summer, applied six coats of expensive flaxseed oil, then found the seasoning no more durable or non-stick than a conventionally seasoned pan—and worse, the first acidic test (boiled wine) stripped the finish as readily as any other oil Seasoning Cast Iron (Flaxseed vs. Old School methods) @ 06:07.

⚡ Action Items

1. If you own a flaxseed-seasoned pan showing cracks or peeling, strip and re-season with grapeseed or refined canola oil. Use 350–450°F in an oven for 30–60 minutes per coat, two to three coats total, then cook with fat regularly. Avoid re-purchasing flaxseed Solved! The Easiest Way to Fix Flaking Seasoning on Your Cast Iron @ 02:04, What's The BEST OIL FOR CAST IRON SEASONING? IT Is NOT Flaxseed Oil! @ 09:30.

2. For new cast iron, buy cheap refined grapeseed, canola, or Crisco from a grocery store. Apply a thin layer (quarter-sized amount), wipe until nearly dry, then oven-bake at 450°F for 30 minutes. Repeat once. Then cook immediately—do not do six oven cycles Cast Iron Skillet Seasoning - A Detailed How-To Video @ 29:44, The Seasoning Oil Scam (STOP WASTING MONEY) @ 05:06.

3. Always use refined (not cold-pressed, organic, or artisanal) oils for seasoning. Check the label: if it lists "fiber," "sediment," or recommends storage in a dark place, it contains particles that will create stickiness. Mass-market brands are reliably refined and cheaper What is the best Seasoning Oil for Cast Iron and Carbon Steel Cookware @ 05:06.

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