Seasoning and maintaining your cast iron cookware

What is the process of seasoning and why is it important to the condition of your cast iron?

Early in its life, a cast iron pan is prepared for use by a process known as ‘seasoning’ (occasionally called ‘curing’), which gives the pan its protective finish, nonstick-ish qualities and black color. A pan is ‘seasoned’ by applying a thin fat or oil (like canola oil or Crisco) to the pan and heating the pan greater than the smoke point of that oil for a period of time. (Example: Crisco smokes at 440 degrees F; You’d season the pan at roughly 490-500 degrees for about an hour).

This process changes the oil from liquid state to a more hardened solid (through a process known as polymerization – fancy word for ‘turn oil to plastic’). This process is usually repeated a few times which makes the pan rust resistant. And unlike most cookware, as you continue to use cast-iron cookware, that super thin layer of seasoning gets stronger and stronger. (And the pan gets increasingly more non-stick and rust-resistant). For example, I have a cast-iron pan that’s been in my family and in continual use since the mid 50’s. (Take that Teflon 🙂 )

Most (if not all) commercially available cast iron pans come from the factory already seasoned. However, if you have stripped a pan, or want to add additional layers to a pan that you have, it is nice to have a process that you follow for seasoning.

As with nearly all things, there is usually more than one way to do it. Described in this document is my method.

What oil to use?

When seasoning, your selection of oil has a number of requirements that you need to balance:

• Ubiquity – How easy is it to find?
• Durability – How long does the seasoning last & how much maintenance does it require?
• Cost – Kinda self explanatory
• Consistency – Do you get reproducible results?

The best oils are generally monounsaturated oils which are neutral in flavor. Oils in this category include (but aren’t limited to) flaxseed, canola, avocado, safflower, olive, grapeseed. Monounsaturated oils generally polymerize better, and you’d want a neutral oil so as to not impart weird flavors. (For example, don’t use sesame oil)

My go to oil of choice is plain Crisco as it is solves all of these. Additionally, when I learned how to season cast-iron from my father and grandmother, this is what they used, and there is some value in “if it ain’t broke, don’t fix it”.

From time to time, I hear someone say, “I use $THIS oil, because it is ‘better'”. Is another oil such as coconut or avocado oil qualitatively better? That’s arguable. I haven’t seen a proper ‘double-blind’ measurement of seasoning oils to confirm or deny. I take the model of ‘if it works for you, then it is the best oil.

In my opinion, why would I spend extra for exotic oils when Crisco gives me the same results? Plain Crisco also solves the consistency & cost requirements quite well. You can find it anywhere and it is quite affordable. And as a bonus, I can fry my chicken in it.

A counter-example is flaxseed oil. Chemically, it appears to be the best oil for seasoning pans, but it doesn’t hold up to the rigors of being used in a daily-driver. More on this later.

What about beeswax?

There are many hybrid oils, such as Buzzywaxx and Crisbee, which include beeswax as an additive to the seasoning fat.

Beeswax has many qualities that make it ideal for usage in cast iron seasoning application. It is water-resistant (which is useful for something you don’t want to rust), dries/hardens at room temperature (which helps with durability – considering that you are going to be actually using the pan), and it is food safe (which is obviously important for cookware).

Given its properties, it is definite worth considering incorporating beeswax into your seasoning methods. And you even get to support a small business in the process if you purchase one of the blends mentioned above.

What about flaxseed oil?

I have been seasoning with flaxseed oil on and off for some time, and I’ve learned a few things:

• The ‘drying effect’ of flaxseed is real. It is one of the reasons why the hybrid fats (like Crisbee and Buzzywaxx) add Beeswax. Beeswax has a similar drying effect.
• Not all flaxseed oils are created equally. The difference between unrefined and refined flaxseed is HUGE. (unrefined flax has a super low smoke point ~225° F; refined flax has a smoke point ~500°F). I have found that not all vendors label this well. Many of the inconsistencies that folks have with flaxseed oil when seasoning can be attributed to this.
• Flaxseed oil takes a decent number of seasonings to get just right. When using flaxseed oil, I do a minimum of 6 rounds of seasoning.

With the above guidance, I have been successful with flaxseed oil. That being said, flaxseed oil is expensive and finicky. Any flaxseed oil that you’d use for seasoning is the expensive stuff that requires refrigeration, so it is hard to justify the cost when there are alternatives (good ole fashioned Crisco and/or the hybrid fats like Buzzywaxx and Crisbee) that are excellent. The juice doesn’t justify the squeeze.

I, like many folks gave flaxseed oil a try after reading this blog. I was getting inconsistent results. And honestly, I was having a bit of a crisis. Was it my technique? Was it my pans? Was it the oil? One of these was suspect. So like a proper geek and inspired by ‘The Martian’, I scienced the s!@# out of this. I bought three 8 inch Lodge pans (you know, for science 🙂 ), stripped them bare, and seasoned them. (one with Crisco as the control, and the other two with 6 rounds of different flaxseed oils).

In the process I learned a lot about flaxseed oil. And as much as the pretentious half of me wanted to have my pans seasoned with organic, non-GMO, free-range flaxseed oil that I sourced from a farmer’s market on a sunny Saturday morning, Occam’s Razor (aka my wallet) disagreed. 🙂

Our choice in oils are subject to both selection & confirmation bias. It is similar to cooking or BBQ in that everyone wants to believe that they have that one special spice, or special technique that sets what they are doing apart. But at the end of the day, a LOT (if not most) of the work is just pure science.

Hell, I am guilty of this myself. Half of why I tried flaxseed oil was because it was ‘better’. Prior to switching to flaxseed oil, I did all of my seasoning with Crisco (like granny and dad taught me). And what I learned is not that I’d veto flaxseed oil, but it requires a little more research before using. The difference between unrefined or refined flaxseed oil matters a ton. And there is something to be said for known quantities. That’s why I primarily season with Crisco or one of the blended oils which contain beeswax. Consistent products = consistent results. Flaxseed is expensive and finicky, caveat emptor.

Included in this document is a listing of various fats and their smoke points to help in your selection of an appropriate oil

Ok, enough with the theory, what’s your technique?

Supplies required:

• lint-free cloth. I use Scott’s Shop Towels
• Your oil.

• Preheat your oven to ~ 200°F
• Place the item (s) in the oven for 20-25 minutes. The goal is to ensure that the pan is completely dry AND warm enough to melt a fat which is solid at room temperature (such as Crisco), but still be easily handled while wearing an oven mitt. Additionally metal expands when heated, so it makes it easier to get the oil into all of the pores of the pan.
• remove the pan from the oven.
• using your lint-free cloth, apply, in a circular motion a very thin layer of your oil to every surface of the pan, inside and out, including the handle. Applying fat to a cast iron pan is like polishing shoes: thinly applied layers are better. Otherwise, the oil will pool and form clumps.
• if necessary, use a clean cloth to remove any excess oil. If you can ‘see’ the oil,you’ve applied too much
• place the pan back in the oven.
• set your oven to ~ 50°(F) higher than the smoke point of your oil. Crisco smokes at 440°, so I set my oven to 490°.
• once the oven reaches temperature, set a timer for 1 hour.
• at the 1 hour mark, turn the oven off and allow the pans to completely cool in the oven.

Repeat 2-4 times. Included below is a video demonstrating how I apply oil to my pans.

Maintaining your cast iron

When you are done using your cast iron pan, cleaning it up and returning it to pristine is pretty simple. After use, hand wash the pan with a mild soap and dry the pan. Then put it on the stove for a couple of minutes (to make sure it is super dry) and then spray with a little spray cooking oil or wipe with about a half-teaspoon of neutral oil. Allow the pan to cool and then put it away. Note: if you have a pan with a lid, it is advised to NOT store the pan with the lid attached. It may trap humid air and cause rusting.

Frequently asked questions

Q – How often should I reseason a pan?
A – Ideally never. With proper care, a pan doesn’t need to be stripped and reseasoned.

Q – When seasoning a pan, I see a lot of people placing their pans in the oven upside down. Is it required?
A – This depends on your technique for applying your oil. I strive to apply oil extremely thinly, so the likelihood of excess oil is next to nil. It doesn’t hurt. (And if by chance you did apply way too much oil, an upside-down pan allows it to drain off)

Q – Should I season a pan that I purchased commercially?
A – This is not strictly required and depends on how much you trust the manufacturer and how much confidence you have in your technique. I generally will add 1-2 rounds of my own seasoning to a brand-new pan, after giving it a nice hot soapy wash. Pans that I have acquired from another person or from antique shopping, I’ll completely strip to bare and reseason from scratch.

Q – Should I use soap on my pans?
A – Modern soap is perfectly fine to use. As mentioned higher in this document, the process of seasoning a pan turns oil into a polymer (read: the high heat in the seasoning process turns the oil into plastic). The only thing that can remove the seasoning from a pan is lye (sodium hydroxide) which isn’t added to most soap anymore or electrolysis.

Q – I have some baked on food that I need to scrub off, what is the best utensil/tool to use?
A – A chain mail scrubber such as one of these or one of these with a built in sponge.