Question from a Carbon Steel Noob.

[brentjharris]

So, at the risk of sounding OCD (and probably a little bit of a sociopath), I have some questions regarding my Aogami #2 steel santoku (Tanaka).

I've attached some photos here. I've used this knife twice now. I've cut some onions, shallots, garlic, carrots, etc. To say I've taken care of cleaning the knife would be an understatement. I'm a home cook so, taking my time is not an issue. Cleaned the knife with a wet cloth and then dry cloth literally after every vegetable. Then cleaned and dried by hand with mild soap and warm water. Dried by hand and laid out to dry before placing back in knife guard and back into its box.

Already I'm noticing some very minor staining. Is this to be expected? Would a rust remover get rid of this? Or should I just leave it? Aside from being obsessive with my new knife, I just want to make sure I'm taking care of it properly and that this is to be expected.

 

[M1k3]

As long as you aren't getting any textured orange/red spots, you're fine. Some foods can leave an orange/red colored patina, mainly garlic. The textured feeling is the thing you'll want to keep an eye out for. Eventually the colors will turn grey to a light black. It's just a patina forming. The darker it is, the less reactive the steel will be. It'll never be like stainless though.

 

[kayman67]

Take a cotton pad, some simichrome and gently clean the blade. The best thing about this is that it won't affect the contrasting layers and will remove anything that resembles a patina or surface rust.
Wash the knife well after.

Honestly, I would just let it be, but just for your peace of mind, that's one way to clean it once in a while.

 

[brentjharris]

As long as you aren't getting any textured orange/red spots, you're fine. Some foods can leave an orange/red colored patina, mainly garlic. The textured feeling is the thing you'll want to keep an eye out for. Eventually the colors will turn grey to a light black. It's just a patina forming. The darker it is, the less reactive the steel will be. It'll never be like stainless though.

Thanks M1k3. Although it's probably hard to see in the photos, this is far from textured - just a very light staining that really is only visible to the obsessive person owning his first Carbon Steel knife. I will take this advice and keep a close eye on it. Thanks!

 

[brentjharris]

Take a cotton pad, some simichrome and gently clean the blade. The best thing about this is that it won't affect the contrasting layers and will remove anything that resembles a patina or surface rust.
Wash the knife well after.

Honestly, I would just let it be, but just for your peace of mind, that's one way to clean it once in a while.

More great advice and put my mind at ease. Thanks kayman67!

 

[Ruso]

Steel “discolouration” is called patina and its normal for carbon steel. If you do not like it, bar keepers friend on a dump sponge will remove it not time. Just wash the knife with soapy water right after.

 

[brentjharris]

Steel “discolouration” is called patina and its normal for carbon steel. If you do not like it, bar keepers friend on a dump sponge will remove it not time. Just wash the knife with soapy water right after.

Thanks Ruso. While I have done a fair amount of reading on patina, I've never seen it in person, so I wasn't sure what I was looking at to be honest. Thanks.

 

[M1k3]

Here's a healthy, stable patina

peaking out from the cladding.

 

[Nemo]

Patina is good. It provides a degree of resistance to rust. A degree.

Having said that, I have read that Japanese chefs tend to polish patina off on a daily basis.

 

[ian]

Having said that, I have read that Japanese chefs tend to polish patina off on a daily basis.

That's bonkers to me. I'm always waiting impatiently for patina to form.

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I'm convinced that patina also gives your knife a somewhat nonstick surface, similar to how your cast iron pans improve with seasoning. (Maybe this doesn't matter much if it's just the core in a stainless clad knife, though.) Welcome the patina. It's amazing.

 

[lemeneid]

That's bonkers to me. I'm always waiting impatiently for patina to form.

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I'm convinced that patina also gives your knife a somewhat nonstick surface, similar to how your cast iron pans improve with seasoning. (Maybe this doesn't matter much if it's just the core in a stainless clad knife, though.) Welcome the patina. It's amazing.

Sushi chefs at least, need to stand in front of guests while preparing food. Not a good impression to whip out your discolored blade for diners to see.

Also single bevels need to be sharper and tend to be sharpened more so patina is removed regularly always.

 

[ian]

Sushi chefs at least, need to stand in front of guests while preparing food. Not a good impression to whip out your discolored blade for diners to see.

Also single bevels need to be sharper and tend to be sharpened more so patina is removed regularly always.

Good points. Also, I take it they regularly (like every day?) sharpen the full bevel, not just the edge.

 

[lemeneid]

Good points. Also, I take it they regularly (like every day?) sharpen the full bevel, not just the edge.

Wouldn’t have the slightest clue on this, not a chef. But I guess definitely enough to not let the guest see an ugly knife. Also, I notice sushi chefs wipe their blades extremely frequently, my guess it’s to reduce flavour transfer, so it should patina as hard or as frequently too.