It's a cliche that there are a lot of opinions about seasoning cookware. Wow is that true - there is very little consensus on a standard approach. Different oils, temperatures, times, goals.

The primary shocking revelation and the reason I am writing this blog post

When seasoning cookware, one should not use heat that is above the smoke point of the oil.

How to pick an oil (probably)

• higher smoke point
• less saturated
• less flavor is better
• less fibers is better

Read on for why...

Findings

• The goal is oil polymerization
• Polymerization happens below the smoke point
• There is no reason to go above the smoke point
• We want to get hot enough to facilitate polymerization, but we do not want to go above the smoke point of the oil, because then it will burn and not polymerize
• this is very rarely stated, even in theoretically reliable sources such as Lodge's own recommendations
• Oils polymerize at any heat below the smoke point (e.g. paintings made with oil paints "dry" over the course of years at room temperature). The hotter, the faster.
• Unsaturated fats polymerize more quickly than saturated fats
• some guides say that in order to achieve polymerization, we must go above the smoke point - I believe these are clearly wrong
• a couple guides, probably overlapping with the above, say: we want both polymerization and burning, because the black ash is part of the finish we are going for
• other guides respond: we don't want to do that, people who want to do that are only going for aesthetics. oddly, some of these same guides which warn against burning do not suggest to pick your temperature based on the smoke point of your oil
• I've only seen one guide (linked below, although I think it's content farmed from some unknown original article) out of dozens which explicitly says to pick your temperature based on the smoke point of your oil, and to stay below it. The second link below says to stay "at or below" - i think "at" is risky.
• Other guides say things which support this, but don't explicitly say this. I really can't emphasize enough how there are many very long elaborate guides, which even talk about the importance of a high smoke point, but do not specify that you should keep your temperature below the smoke point.
• Flaxseed oil was in vogue for a while, and now some people are saying it flakes after a while. It has a very low smoke point of 225! So I suspect people using it, while using typical temps of 450, are putting on tons of layers of ash - it looks great but doesn't actually result in much polymerization.
• Grapeseed oil seems to be an emerging favorite. I wonder if part/much of this is because it has a higher smoke point than Canola oil, so people are accidentally achieving less burning (if using same temp for both).
• some oils have fibers, which creates a lower smoke point. so, even if other things are equal (such as the polymerized oil being just as good for any oil), the presence of fibers is probably bad, because after seasoning, they will burn during cooking (although maybe this will be very fast and minor). A higher smoke point probably generally correlates with fewer fibers. So higher smoke point oils could be preferable for (at least) this reason.
• The presence of flavor implies the presence of non-oil compounds, and we probably want as much oil as possible and nothing else, so a less-flavorful oil is probably preferable for this reason.
• Lodge uses soybean oil in their factory
• Lodge seasoning spray that they sell to you is 100% canola oil
• You can also season other types of cookware, such as aluminum baking sheets and muffin pans (which I have done with good initial results), and carbon steel, using the same method. People also talk about seasoning stainless steel. I think the seasoning won't stick as well to this shiny surface but I haven't tested it.

Questions

• After different oils polymerize fully, do they have differnt attributes?
  • strength/durability
  • non-stickness
  • max heat
• how long does it really take for the thin layer of oil to fully polymerize? Does this differ significantly by oil?

My method for now

I've done 3 layers with coconut oil at 325 and it looks fantastic and to my eye seems pretty non-ashy. Don't know how it performs yet.

My experiments so far were pretty inconsistent because I was researching and doing it at the same time so I used different temps and durations in different phases.

Going forward, I'm going to use avocado oil at a higher temp (well below smoke point).

If the theory that the temp doesn't need to be super high to have good polymerization is correct, that could make the process more convenient- it's more convenient to work with 350F vs 450F+ as items go in and out of the oven.

Appendix

• https://www.prolinerangehoods.com/blog/how-to-season-cast-iron-coconut-oil/
• https://www.castironcollector.com/seasoning.php (i discovered this after my initial research and while writing this - i didn't read it carefully yet, will do so eventually)
• https://www.youtube.com/watch?v=2NOZwyiNSZg
• https://chemistry.stackexchange.com/questions/169685/after-an-oil-polymerizes-what-is-its-smoke-point (in typical SE fashion, downvoted but still useful almost-answers in the comments )
• https://en.wikipedia.org/wiki/Template:Smoke_point_of_cooking_oils
• https://www.lodgecastiron.com/cleaning-and-care/cast-iron/oils-cast-iron-cooking-and-seasoning
• https://www.lodgecastiron.com/discover/cleaning-and-care/cast-iron/all-about-seasoning
• https://www.lodgecastiron.com/product/lodge-seasoning-spray-oil
• https://fieldcompany.com/pages/how-to-season-cast-iron-pan-skillet
• Lodge Factory: https://www.youtube.com/watch?v=NEQP94YbYFo

Thanks to Zachary Hudson, Associate Professor at The University of British Columbia Department of Chemistry, for answering a couple questions!

Very          Water                              Very
Cold        Freezes               Nice            Hot
-20C             0C                20C            40C
  0F            32F                70F           100F
   |              |                  |              |
   --------------------------------------------------
                      |    |               |
                    40F  50F             82F
                     4C  10C             28C

Read on to learn about how this amazing cultural and scientific product came to be...

Here's a funny and informative graphic that was going around a while ago:

So from here we can see that Fahrenheit is clearly the superior scale for human environments.

But how does someone familiar with Celsius understand what it's like outside based on the Fahrenheit weather, and vice-versa?

This Hank Green tweet proposed a simple way to think about Celsius:

Hey, having a hard time with Celsius? Ignore the second number and it’s basically just how hot it is on a scale of 0 to 5.

Pretty good, but I thought, it could be better. I'd like to have a mental scale that I think of as analogous to 0–100 in F. Let's start with a few facts:

• around 70 F is "nice"
• 70 F is 21 C
• 32 F - water freezes
• 0 C - water freezes
• 0 F is -18 C
• 100 F 38 C

So if we're going for a good enough mental scale, maybe we can say that the range of Celsius aligning with Fahrenheit is about -20–40. There is also the sort-of pattern that frozen water is about a third from the bottom of the range, nice weather is about 2/3 from the bottom.

So we have:

Fahrenheit

• 0 is Very Cold
• 32 is Frozen Water
• 70 is Nice
• 100 is Very Hot

Celsius

• -20 is Very Cold
• 0 is Frozen Water
• 20 is Nice
• 40 is Very Hot

In addition to that, a few other mnemonics/markers:

• 40F is 4.4C
• 50F is 10C (as in 50.0̅ is 10.0̅ which is very shocking to me)
• 82F is 28C

I could make separate lists for single-payer vs. single-provider, but there are enough hybrid models and variations that it's probably interesting enough to just make a single list with qualifiers.

I'm limiting systems to those which cover all costs for all people. So for example in the case of the countries which have mixed public/private insurance, people in those systems have the option to only use the public offering, and get almost all their needs covered by it.

This list is probably very incomplete!

1. Brazil - single-payer/provider - 220MM
2. US All Systems - single-payer/provider - 128MM
3. US Medicaid - single-payer - 75MM
4. United Kingdom - single-payer/provider - 66MM
5. France - public/private-payer mix - 65MM
6. South Korea - single-payer - 51MM
7. Spain - public/private-payer mix - 47MM
8. US Medicare - single-payer - 44MM
9. Canada - single-payer- 37MM
10. Nordic Countries - single-payer/provider - 27MM
11. Australia - public/private-payer mix - 25MM
12. Taiwan - single-payer - 24MM
13. US VA - single-provider - 9MM enrolled (2014)

Notes

• If I'm wrong about anything here, please let me know! I just whipped this together with an hour of research.
• There are a few large systems where I didn't have time to figure out what percent of people's needs were covered. Examples are Pakistan and Russia.
• Japan seems to have a very well regulated and effective healthcare system, but also seems to have a large portion of the population on private insurance, so I chose not to include them in the list.
• There is no wikpedia page about single-provider healthcare systems. The concept of single-provider is seen as a subtopic of single-payer.
• I couldn't find a comprehensive list comparing healthecare systems in the world, on wikipedia or anywhere else.