# Carbon steel knife care/maintenance



## halmstad

Just purchased my first carbon steel knife and am wondering if there is anything I should be aware of in it's maintenance.

Of course, I wash and dry all of my knives after each task. That goes without saying. I will be cutting a lot of lemons, onions, etc that will rust or discolor the blade. Does this occur only if I let them sit too long after cutting or is it something that I will just have to accept owning carbon steel?

I own the Norton combination water stones-440/1000 and 4000/8000 along with the stone leveler(not sure what it's called). So I think I'm set on sharpening. What about a honing rod? I've read in some places that you shouldn't use honing rods with Japanese knives and others that recommend ceramic rods only.

Is there anything else I should know or just cut away as usual? Not sure what exactly to ask. Just looking for some pointers.

Thanks


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## phatch

It will darken over time and use. Depending on which carbon steel it is, it can darken very quickly, particularly with fruits.

Cleaning quickly is the main thing and not worrying about discoloration as it occurs.

BDL espouses a baking soda and scotchbrite regimen.


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## chrislehrer

If you cut lots of lemons and onions, you should plan to spend the first couple of weeks with a slightly damp towel and a very dry one within immediate reach. Every time you finish cutting something like this, wipe well with the damp towel, and if you are pausing for even a minute or so follow up with the dry. After a time, the knife should develop a distinct dull-gray-blue patina. Until it does so, some of your first slices of acidic foods are going do discolor fast if you don't do something about it -- this is particularly true of onions. So you may want to have a bowl of cold water to dump your cut onions into, which will rinse off the weirdness fast.

One great solution is to do something like make French onion soup, or set up your prep station to break down a huge mass of onions all in one go. Make sure you've already started the patina -- cutting almost anything for a day or two will do that. Then just wade into your onions, wiping damp often as you go. By the end of the shift (or task, if this is at home), your knife will be very far along the way to a great patina that will not react with onions and lemons in the future.


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## halmstad

CL-Thanks for the great advice.

It is a Misono Swedish Steel. Once I actually receive the knife, I will bring it to work and make a grand amount of caramelized onions, wiping as I go. And i'll probably cut a large amount of onions for the day guy's French onion soup.

Is the "weirdness" an irony kind of smell or something different? Will the onions also discolor/stink if I don't drop them into a cold water bath?

I can't wait for this knife to arrive! I've used a few but never owned carbon steel knives and always wanted one.


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## chrislehrer

At first, yes, the onions will discolor and possibly smell funny if you don't drop them in water. How much, and how strongly it smells, depends enormously on the knife. But this effect goes away quite quickly -- especially with the quantities you're going to be cutting. Just don't freak out when, after a single day of onion prep, the knife looks much different from the way it did when you got it.

Some steels will take a continual light polish, no matter what they cut, and will develop a very light misty-gray color. I personally have only seen this in fairly high-end usuba, but then I don't have the widest experience. Most people don't try to maintain a constant polish on a gyuto anyway, so you just let it dull to where it wants to go. My Masamoto KS-3127, for example, quickly takes on a strangely attractive dull color that to my eye says, "I am evil and wish to do dreadful things to foods. Let's go play." It's what some people seem to see in certain motorcycles, though I can't much identify with that one. By contrast, my Aritsugu usuba and my unnamed blue-steel yanagiba (long story, but it's medium high-end) simply have a faint not-quite-shiny thing that says, "I have a sufficient patina, so don't worry about it." And then there are people who use mustard and stuff to force a really deep blue-gray patina.

I can't speak to the knife you're going to be using, but I do think that for the first day or two of heavy service, you're going to need to assume that anything strongly acidic may not only affect but be affected by the knife, and work around that.


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## halmstad

That's cool. All carbon steel knives I've used were very old and already had a very good patina to them. The thing is that they were always so sharp. I'm not at all concerned about steel discoloration, I am expecting it. More or less wondering how not to ruin the blade. 

Believe me, I'm very anal about the care of my stainless blades. Washing and drying after use is the norm. I don't want to baby the knife is what I'm getting at. If I have to come in early one day, send the prep guy home and cut 25lbs of onions so be it. I don't want a polished knife. I want my knife to have a character of it's own.


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## kokopuffs

After slicing acidic foods or any foods for that matter, I briefly rinse and then dry the blade.

When sharpening using my Norton stones, I spray them with water and not oil as a "lubricant" that floats off the particles.  Using water, I get a much sharper edge and achieve it more quickly than with oil.

If you insist on using oil for your stones, go to a tack and feed store (horse supply) and get yourself a gallon of mineral oil because it'll cost less than $15.  Don't bother with the commercial products labeled as honing oil since their usually mineral oil rebadged.


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## boar_d_laze

You'll smell the food reacting with the steel, not just the steel. In the case of onions the smell will be somewhat sulphrous; in the case of meat, somewhat coppery; etc. I suggest rubbing the knife down with a baking soda paste before each shift for the first week or so, whether or not you're ultimately going to force a patina. That will keep the stink down significantly.

This whole thing may be a red herring with me reacting to kokopuff's advice, but... Don't bother using oil stones on a Misono Sweden, whether dry, with water or with oil. They're too slow. Furthermore, I own and use Norton India stones for a lot of different knives, but neither they nor Crystolons will not give you anywhere near the finish a Sweden should have. I forget (or never knew) where we stand _vis a vis_ your knowledge of water stone lore, but if you don't know which stones are appropriate for you, your level of expertise, your budget and your Sweden, just ask.

So many commas, so little time,

BDL


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## chrisbelgium

halmstad said:


> CL-Thanks for the great advice.
> 
> It is a Misono Swedish Steel. Once I actually receive the knife, I will bring it to work and make a grand amount of caramelized onions, wiping as I go. And i'll probably cut a large amount of onions for the day guy's French onion soup.
> 
> Is the "weirdness" an irony kind of smell or something different? Will the onions also discolor/stink if I don't drop them into a cold water bath?
> 
> I can't wait for this knife to arrive! I've used a few but never owned carbon steel knives and always wanted one.


I have no idea how your beautiful Misono carbon knife will react to acidic food.

But, the main reason why carbon knives aren't my favorites happened when I cut 3 pine-apples to make jam with a carbon knife. Unbelievable how fast and violent the acidity from these fruits react with the steel! It stinks, a lot! You also need to know I just mirror-polished that thing!

Couldn't be plain oxidation or the blade would show rust. Instead it showed most of the rainbow colors. Luckily enough the knife doesn't react all that much when cutting meat, the purpose I bought the knife for.


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## chrisbelgium

By the way, this is how the knife looked like after polishing for many hours... a week before I did the pine-apple jam!


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## kokopuffs

@BDL:  I was referring to older carbon steel and not some newly manufactured Misono knife.  I also find that my India stones perform their tasks much more quickly by using water instead of oil as the liquid of choice.

And based on the few photos I've perused of the Misono Sweden, I see no surface pitting on that blade and therefore I'm led to believe its metallurgy differs from the that of the older Sabatiers that I own.

And funny, I never noticed any off odors from my old Sabatier after cutting most any acidic food including fruit.  And to blazes with the mirror finish: it doesn't work for me.


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## boar_d_laze

Carbon Sabatiers can take, hold and benefit from a finer grit than a fine India.  They're in that happy group of knives which sharpen almost equally well on oil stones and water stones; a "Surgical Black" or Translucent Arkansas make good finishers for them, and so do coticules if you want that much polish.  I sharpen mine -- and I have a bunch -- on Indias, Arks, a variety of water stones, and a variety of strops and stropping compound.  They take such a great edge so easily it almost isn't fair.

A Misono Sweden gets just as sharp and certainly holds the edge better.  It just can't compete with Sabatier's profiles -- that takes a Masamoto.

The idea of using any liquid is not to lubricate the stone but to float the swarf and keep the stone from clogging.  Oil, the most viscous of the good liquids does that best, but unfortunately it also slows the process the most.  And ultimately the oil/swarf mix works its way into the stone's pores and is very difficult to clean -- making the stone very slow indeed. 

In my experience, sharpening dry on (nearly all) oil stones (specifically including but not limited to Norton India stones) works even better than water, which works better than soapy water, which works better than oil.  You'll have to clean your stones more frequently, but since the dishwasher does most of the work... 

However, it's something of a red herring since no one suggested sharpening on oil.  Or, did they?

BDL


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## kokopuffs

BDL:  when I transitioned my stones from oil to water, I soaked them for 2 to 4 months in kerosene to relieve them of their previous oil treatments as it were.  In your opinion, would it still be okay to clean them in the dishwasher without there being any residual oil odor or oil film coating the dishwasher?  In the dishwasher, do you also use dishsoap for cleaning the stones?  Do you place the stones in the dishwasher along with other kitchen plates and utensils?


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## boar_d_laze

In the dishwasher with soap and everything else.  Sometimes it takes more than one ride.  In extremis or as an alternative they may be boiled in water with a little dishwasher detergent in a non-reactive pot for ten minutes or so. 

If the stones are very dirty, they might need to be scoured with scouring powder and a brass bristled brush before washing.  I do this routinely. 

If the stones are old and stained and the combination of scouring, the dishwasher leaves them clean but still looking dirty, and you care, try rubbing them with Mr. Clean Magic Eraser.  I like to keep my stones pretty clean as a check on their effectiveness.  Clean stones are faster and scratch less.

You can also scour with mineral spirits or kerosene to remove staining, but must wash the stones very thoroughly after.

BDL


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## halmstad

BDL-I do have some questions about stones. I have been checking out Japanese water stones on a few websites and have read some posts both here and on foofieforums.  

My sharpening skills are what I would call average. I do sharpen my knives as needed but have never owned anything but Wusthofs and the global. Now with 3 new Japanese knives that will get much regular use, I of course want to keep them tip top. I don't have any problems sharpening the germans and I get a really nice edge on the global that last me a good amount of time.

I would be looking for a 1000 grit stone and possibly 6000-8000. I don't really know what my budget is right now. The only thing I can throw out there is paying $100 for each stone.

The main thing is getting stones that will work well with all 3 knives-Masamoto VG, Fujiwara FKM and Misono Swedish. My girlfriend will kill me if I spend as much money on the stones as I did the knives.....


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## aliesha11

Niiice reply!


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## amateur-cook

Interesting threat, and what I like the best is that there is no name-calling or other insulting here!


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