# Cutting Tomatoes with Your Good Knife?



## chuck_d (Jul 31, 2016)

I've been told not to cut tomatoes with my nice carbon steel core knife, and to use a cheap serrated knife instead. Because they are too damaging to the knife and it's better to just use a cheap blade instead.

What do you all think? Are there other foods you avoid using your best knives on as well, like citrus?


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## XooMG (Jul 31, 2016)

You seem to have an abundance of unneeded advice, I think.

Cut a tomato with your carbon knife and wipe it or rinse. Is the patina going out of control and leading to rust? If it's hard to manage for you, just swap to a stainless for the task.

Do not smash or torque your edge. Do not cut on hard surfaces. Keep it wiped and washed when working with stuff that oxidizes iron faster. Keep it sharp and do maintenance thinning when convenient. These are all pretty easy to figure out.

Unless you are using a yanagiba to chop pumpkins, I think you'll be fine.


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## havox07 (Jul 31, 2016)

I can't see it being that bad. Knife wear stocks tomatoes to show people how their knives cut.


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## aboynamedsuita (Jul 31, 2016)

I cut tomatoes with CS knives, I'd maybe consider letting a bit of a patina build first, and acknowledge that it may cause the edge to lose its keenness quicker than less reactive produce


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## JaVa (Jul 31, 2016)

Tomatoes does take away the edge much faster than other veg. (It is a fruit actually and not a veg).
But not fast enough that it should worry any home user. 

We go thru about 20-30 kilos of tomatoes a day at the mad house. When using my Tanaka B2 Nakiri after about 10 kilos I`ll need a quick touch up. Without the tomatoes I´ll get thru a full day or two. 

If I use a stainless knife I can prep about three to four times as much. Without the tomatoes both knives will last about the same.

So yeah, they do wear on your carbons a bit more then most other stuff. Should you be concerned? Nah, not the least bit!


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## chuck_d (Jul 31, 2016)

Thanks, that was my suspicion, but I figured I'd check with y'all before ignoring that advice.



JaVa said:


> Tomatoes does take away the edge much faster than other veg. (It is a fruit actually and not a veg).
> But not fast enough that it should worry any home user.
> 
> We go thru about 20-30 kilos of tomatoes a day at the mad house. When using my Tanaka B2 Nakiri after about 10 kilos I`ll need a quick touch up. Without the tomatoes I´ll get thru a full day or two.
> ...



Yeah, well, I guess it depends on your definition of fruit and vegetable. Botanically, things like tomatoes, cucumbers, avocados, squash, stuff with seeds are fruits. I'm not sure vegetable is botanically defined. In a culinary sense, vegetable means savory plants and fruit means sweet plants. I can see tomatoes being on the boarder between the two, but zucchini and cucumber would fall into the savory category. After getting a math degree, I see things like this as it all depends on your definitions. Let F be a plant with a sweet flavor and V be a plant with a savory flavor. Or let F be plant with seeds and let V be a plant without seeds. Also, strawberries and raspberries aren't actually berries, but a banana is, as well as a tomato in fact, and pumpkins and watermelons, botanically speaking that is.


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## JaVa (Jul 31, 2016)

I actually had to go check. 

The almighty Wikipedia, in it´s great wisdom says that a tomato is a berry type fruit.
Funnily enough Finish Wikipedia said only fruit? Go figure?

Aanyway... berry or fruit? My point was only meant to underline of the acidity of them. As most fruits are very acidity (and mostly veggies are not). Thats probably why someone would suggest not to use carbon knives for cutting tomatoes?

...Aand then most fruits would be off the table also. (pun intended)


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## chuck_d (Jul 31, 2016)

JaVa said:


> I actually had to go check.
> 
> The almighty Wikipedia, in it´s great wisdom says that a tomato is a berry type fruit.
> Funnily enough Finish Wikipedia said only fruit? Go figure?
> ...



Yeah, I was just nerding out. I figure it is the same reason as he said not to cut citrus as well, these are highly acidic fruits. But I don't think it's going to be that big of a deal. If the edge is lost more quickly, I'll just sharpen more frequently. If that becomes a problem then I'll switch to using a cheaper knife. But I'm dropping a lot of coin on this knife, not as much as one could. In the grand scheme of JKnives, this is inexpensive. However, in the grand scheme of most people's lives and budgets, it's not cheap. After spending that kind of money, I do want to protect it, but I also want to use it. It's a tool, not a display piece, it's meant to be used. It would be foolish to spend this money and then do so much cutting without it. Over time, I'll build up a decent collection of various knives, many dedicated to specific tasks. Until that time however, a gyuto is a general all-purpose knife and I'm going to generally use it for all purposes.


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## bennyprofane (Jul 31, 2016)

Which Gyuto are you getting?


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## chuck_d (Jul 31, 2016)

bennyprofane said:


> Which Gyuto are you getting?



It's between the Itto Ryu 210mm or the Masakage Yuki 210mm. I'll know for sure tomorrow or the next day. Both of them are Shirogami #2 core with stainless cladding. The Itto has kurouchi finish and the Masakage has a pear finish, both have oval handles. The Itto is slightly heavier (by 0.2 ounces), slightly longer in the blade (by 3mm), slightly shorter overall (by 19mm), slightly thicker in the heel (by 0.7mm) and slightly taller (by 2.7mm). Oh, and the Masakage is slightly harder, the Itto is listed at 61+ while the Masakage is listed as 62/63.

So in general, very similar knives, with only a few minor differences. What I like about the Masakage is that there seems to be a lot more users out there, while the Itto seems to be fairly new to the scene so not much info on quality/durability/longevity of the knife. I think the Masakage is probably a better known entity. But it'll still probably come down to which feels best in our hands, if it's too hard to decide based on that we'll go with the Masakage.


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## daveb (Jul 31, 2016)

Education will teach you that a tomato is a fruit.

Wisdom is knowing not to put it in a fruit salad.


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## supersayan3 (Jul 31, 2016)

Tomato has too much water, and decreases the edge quicker than anything else.
It also leaves ugly colored patinas.
But it is a pure joy to cut lots or loads of tomatoes with a just sharpened carbon, feel the sweetness and as yiu continue to cut to a satisfactory degree, with just a touch up carbons become fully sharp again, and you experience one more time, the sweetness of their cutting performance


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## Ruso (Jul 31, 2016)

supersayan3 said:


> Tomato has too much water, and decreases the edge quicker than anything else.



I do not think water content is a culprit. At the end of the day cucumber has more water content and tomato is similar to green cabbage with 94% water. Having an acidic content is what kills it; as previous posters mentioned.


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## LifeByA1000Cuts (Aug 1, 2016)

@daveb eclecticism is knowing som tam pon lamai.

I always found tomato juice even seems to have a slightly skin irritating quality (not making you get a rash or something, but there is still something that can be felt) if left there for a length of time...


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## Timthebeaver (Aug 1, 2016)

Expensive, esoteric kitchen knife which you shouldn't cut tomatoes with? Really?


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## Mucho Bocho (Aug 1, 2016)

Timthebeaver said:


> Expensive, esoteric kitchen knife which you shouldn't cut tomatoes with? Really?



My thoughts exactly. This thread dove tails nicely with the "how to wash a knife" lots of insightful conversation going on these days.


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## panda (Aug 1, 2016)

if you're not going to cut tomatoes with your expensive knife, why even get one in the first place? i'm pretty sure tomatoes are cut very often in most homes..


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## daveb (Aug 1, 2016)

panda said:


> if you're not going to cut tomatoes with your expensive knife, why even get one in the first place?.



A tomato or a knife?


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## chuck_d (Aug 1, 2016)

Daveb, you're going to have to change your signature to older and wittier.


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## Pensacola Tiger (Aug 1, 2016)

daveb said:


> A tomato or a knife?



Why not both?


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## Noodle Soup (Aug 1, 2016)

There is no way I'm going to tear tomatoes apart with a crappie serrated knife. If it won't glide through a tomato leaving paper thin slices, it either needs sharpening or it doesn't belong in my kitchen.


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## supersayan3 (Aug 1, 2016)

Ruso said:


> I do not think water content is a culprit. At the end of the day cucumber has more water content and tomato is similar to green cabbage with 94% water. Having an acidic content is what kills it; as previous posters mentioned.



Tomato water I meant. 
You keep on cutting tomatoes with a carbon knife, after a point your edge will be completely dull


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## LifeByA1000Cuts (Aug 2, 2016)

" i'm pretty sure tomatoes are cut very often in most homes.."

I think some here do not like to refer to that as cutting 


I guess dicing warm tomatoes (just skinned by blanching, as would be common in making sauces from fresh ones) doesn't exactly help either (acids are more reactive the warmer they are)....

@Noodle soup that's why we sooner or later add some esoteric and expensive stainless I guess ... or keep the G***l around 
Interestingly, G***** makes a serrated tomato knife too even though their non-serrated ones can be made quite tomato-capable even when using their recommended pull through sharpener.


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## TimH (Aug 2, 2016)

daveb said:


> Education will teach you that a tomato is a fruit.
> 
> Wisdom is knowing not to put it in a fruit salad.



The Supreme Court disagrees with you. See Nix v. Hedden (1893) in which SCOTUS ruled unanimously that the tomato is a vegetable.


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## chuck_d (Aug 2, 2016)

TimH said:


> The Supreme Court disagrees with you. See Nix v. Hedden (1893) in which SCOTUS ruled unanimously that the tomato is a vegetable.



Which was the precedent for the Reagan administration calling ketchup a vegetable?


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## ManofTaste (Aug 2, 2016)

If resharpening my knife is the price I have to pay, I am still ready, eager, and willing to slice transparently thin slices of tomato with it -- especially when company is around.
:knife:


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## Noodle Soup (Aug 2, 2016)

:goodpost:


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## caerolle (Aug 2, 2016)

chuck_d said:


> It's between the Itto Ryu 210mm or the Masakage Yuki 210mm. I'll know for sure tomorrow or the next day. Both of them are Shirogami #2 core with stainless cladding. The Itto has kurouchi finish and the Masakage has a pear finish, both have oval handles. The Itto is slightly heavier (by 0.2 ounces), slightly longer in the blade (by 3mm), slightly shorter overall (by 19mm), slightly thicker in the heel (by 0.7mm) and slightly taller (by 2.7mm). Oh, and the Masakage is slightly harder, the Itto is listed at 61+ while the Masakage is listed as 62/63.
> 
> So in general, very similar knives, with only a few minor differences. What I like about the Masakage is that there seems to be a lot more users out there, while the Itto seems to be fairly new to the scene so not much info on quality/durability/longevity of the knife. I think the Masakage is probably a better known entity. But it'll still probably come down to which feels best in our hands, if it's too hard to decide based on that we'll go with the Masakage.



You realize these are both handmade knifes, and are going to vary, right? And that those measurements are probably from one example picked out of a stack of boxes of each model?

I have never seen, much less used, a Yuki, but I got an Itto 240 a couple of weeks ago and it has become about my favorite knife. The Yuki probably holds an edge better, but has a reputation for being a bit wedgy, and I am really not at all a fan of the curved choil. It is very popular, though, and really pretty. Plus it has a nicer handle.


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## foody518 (Aug 2, 2016)

chuck_d said:


> Which was the precedent for the Reagan administration calling ketchup a vegetable?



Isn't pizza now considered to contain a serving of vegetables now on account of the tomato sauce (according to the most recent health/nutrition/MyPlate guidelines)?

With rationalizations like these I hope no one is sincerely wonder about our sub-optimal health effects... :scratchhead:


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## LifeByA1000Cuts (Aug 3, 2016)

The "serving" (aka "spoonful of something") screwed us all twice here...


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## Steampunk (Aug 3, 2016)

I cut tomatoes all the time with both Aogami and Shirogami carbon steels... Aogami #1/Aogami Super both hold up pretty well to this duty, as their wear characteristic when exposed to acids is to get 'toothier'. Shirogami #2 loses bite much quicker with tomatoes due to the absence of Aogami's more resistant carbides (Tungsten, most notably, with a bit of chromium, and a little bit of Vanadium in AS.), and patinas quicker, but is far from unsuitable for use with this product. 

If you plan on cutting a lot of tomatoes with a Shirogami knife, my experience has been that starting with a toothier edge than you normally might apply will help to keep it biting longer. I sometimes finish my Yuki on my Gesshin 2K, JNS Red Aoto (2-4K grit blend; love this stone for white steel.), a White Binsui (~1-2K equiv. J-Nat), or something in this range if I know that I'm going to be cutting acidic ingredients with white steel. Shirogami still gets hair-shaving sharp at this level, but the coarser finish takes longer to lose its toothiness. 

Hopefully this helps...

- Steampunk


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## chuck_d (Aug 3, 2016)

Steampunk said:


> I cut tomatoes all the time with both Aogami and Shirogami carbon steels... Aogami #1/Aogami Super both hold up pretty well to this duty, as their wear characteristic when exposed to acids is to get 'toothier'. Shirogami #2 loses bite much quicker with tomatoes due to the absence of Aogami's more resistant carbides (Tungsten, most notably, with a bit of chromium, and a little bit of Vanadium in AS.), and patinas quicker, but is far from unsuitable for use with this product.
> 
> If you plan on cutting a lot of tomatoes with a Shirogami knife, my experience has been that starting with a toothier edge than you normally might apply will help to keep it biting longer. I sometimes finish my Yuki on my Gesshin 2K, JNS Red Aoto (2-4K grit blend; love this stone for white steel.), a White Binsui (~1-2K equiv. J-Nat), or something in this range if I know that I'm going to be cutting acidic ingredients with white steel. Shirogami still gets hair-shaving sharp at this level, but the coarser finish takes longer to lose its toothiness.
> 
> ...



Thanks for such a detailed and helpful reply. That's some great information to know. The Masakage Yuki is Shirogami #2, so I appreciate the suggestion to start with a toothier edge if I have a lot of toms coming up. My sharpening stones are not the nice quality name brands, but I've got a 400/1000 combo and a 3000/8000 combo. So maybe I just don't pull out the second stone at all if I'm going to be slicing up tons of tomatoes (or citrus). Those tips are much appreciated!

Cheers,
chuck_d


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## Steampunk (Aug 3, 2016)

chuck_d said:


> Thanks for such a detailed and helpful reply. That's some great information to know. The Masakage Yuki is Shirogami #2, so I appreciate the suggestion to start with a toothier edge if I have a lot of toms coming up. My sharpening stones are not the nice quality name brands, but I've got a 400/1000 combo and a 3000/8000 combo. So maybe I just don't pull out the second stone at all if I'm going to be slicing up tons of tomatoes (or citrus). Those tips are much appreciated!
> 
> Cheers,
> chuck_d



Your Yuki - at least if they are still finishing them this way - will ship with an edge that's about 13-15 degrees per side, and sharpened with a different grit on each side. On one it's ~1K, on the other 6-8K+. For a factory edge it's pretty stellar; you could also try this trick with dual-grit sharpening to keep it biting, but it's a little fiddlier than simply sharpening to a single lower grit. The steel is pretty hard for White #2, so can support a steeper edge than the factory provides as long as your cutting technique is sound. 11-12dps is a nice balance; micro-bevel if you rock. 

It's also a very thin edge, and Shirogami sharpens really quick, so be careful not to over-sharpen; the 1K will be plenty to start with unless it is severely damaged, and for touch-ups your 3K will probably suffice. Thinning-wise, the bevels on mine were pretty consistent (And slightly concave.), but that may have changed. The SS cladding actually isn't bad to thin, and takes on a nice contrast if you want to play with natural stones (It also takes on a light patina, even though it's SS.)... If you ever want to upgrade your stones, I would suggest the JNS Red Aoto as a finisher if you have a steady hand (It's a soft stone, but this steel at this heat treatment loves it!); it also responds well to J-Nats if you want to go finer. Setting the initial bevel tends to go better with a slightly harder stone in the 1-2K range (1K Chosera, 1K Shapton Glass Stone, 2K Gesshin, etc.). If you aren't super steady (The factory bevel is tiny, and should be kept thinned that way as it thickens up kinda quick.), it also does well on a 3-4K Shapton Glass Stone. I personally wouldn't go finer than this on synthetic stones for a hard working knife, as my experience with Shirogami #2 in the iterations I have tried is that at higher [synthetic] grits it loses its toothiness before it actually dulls (You can still shave hair, but it struggles to bite on peppers.). 

Hopefully this helps... Enjoy your knife! 

- Steampunk


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## ThEoRy (Aug 3, 2016)

This thread is still alive? First we're afraid of squash, now were afraid of tomatoes. Man **** it! Grab a knife and start cutting ****.


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## panda (Aug 3, 2016)

You shouldn't wash your carbon knives because water causes rust.


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## daveb (Aug 3, 2016)

Have thought about going for popcorn.....


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## chuck_d (Aug 4, 2016)

Steampunk said:


> Your Yuki - at least if they are still finishing them this way - will ship with an edge that's about 13-15 degrees per side, and sharpened with a different grit on each side. On one it's ~1K, on the other 6-8K+. For a factory edge it's pretty stellar; you could also try this trick with dual-grit sharpening to keep it biting, but it's a little fiddlier than simply sharpening to a single lower grit. The steel is pretty hard for White #2, so can support a steeper edge than the factory provides as long as your cutting technique is sound. 11-12dps is a nice balance; micro-bevel if you rock.
> 
> It's also a very thin edge, and Shirogami sharpens really quick, so be careful not to over-sharpen; the 1K will be plenty to start with unless it is severely damaged, and for touch-ups your 3K will probably suffice. Thinning-wise, the bevels on mine were pretty consistent (And slightly concave.), but that may have changed. The SS cladding actually isn't bad to thin, and takes on a nice contrast if you want to play with natural stones (It also takes on a light patina, even though it's SS.)... If you ever want to upgrade your stones, I would suggest the JNS Red Aoto as a finisher if you have a steady hand (It's a soft stone, but this steel at this heat treatment loves it!); it also responds well to J-Nats if you want to go finer. Setting the initial bevel tends to go better with a slightly harder stone in the 1-2K range (1K Chosera, 1K Shapton Glass Stone, 2K Gesshin, etc.). If you aren't super steady (The factory bevel is tiny, and should be kept thinned that way as it thickens up kinda quick.), it also does well on a 3-4K Shapton Glass Stone. I personally wouldn't go finer than this on synthetic stones for a hard working knife, as my experience with Shirogami #2 in the iterations I have tried is that at higher [synthetic] grits it loses its toothiness before it actually dulls (You can still shave hair, but it struggles to bite on peppers.).
> 
> ...



Dude, thanks again. That was definitely helpful. The info that came with the knife mentioned that it was sharpened with different grits on each side of the blade, but not which is which. Do you happen to know which side was finished with a higher grit? Or I guess more important than how it came from the factory, I'm right-handed, is sharpening one side with a higher grit better or does it only matter that they are different? Same deal with the angles, does it matter which one is steeper? I've only just started sharpening, and have never done any thinning, so I'll have to read up on how to do that and start practicing. I was never intending to use the 400 on this knife, that's for knives which have seen some serious abuse or are extremely dull. I wasn't sure if I should do touch-ups with the 3000 or 8000, so I guess I'll stick with the 3000 based on this. I really appreciate you sharing your experience and this information.


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## Steampunk (Aug 4, 2016)

chuck_d said:


> Dude, thanks again. That was definitely helpful. The info that came with the knife mentioned that it was sharpened with different grits on each side of the blade, but not which is which. Do you happen to know which side was finished with a higher grit? Or I guess more important than how it came from the factory, I'm right-handed, is sharpening one side with a higher grit better or does it only matter that they are different? Same deal with the angles, does it matter which one is steeper? I've only just started sharpening, and have never done any thinning, so I'll have to read up on how to do that and start practicing. I was never intending to use the 400 on this knife, that's for knives which have seen some serious abuse or are extremely dull. I wasn't sure if I should do touch-ups with the 3000 or 8000, so I guess I'll stick with the 3000 based on this. I really appreciate you sharing your experience and this information.



You can see by looking at the edge which side was sharpened with each grit; one edge bevel will be shinier [finer], and the other [coarser] will have a more visible scratch pattern. However, which side it is on doesn't really affect you, so it's a bit irrelevant. This is just one technique to mix grits for a toothier edge that still has a bit of refinement; there are others (Sharpening the edge on your 1K stone, and then doing just a few edge trailing passes on both sides on your 8K is another; not totally converting the scratch pattern, but simply toning down the teeth a bit.)... Angle wise, the Yuki is ground pretty symmetrically, and the edge is sharpened 50/50 with both bevels roughly similar in degree. You don't really need to be concerned about asymmetry. You can, however, lower them a bit if you wish; it has been my experience that the factory bevel angle is a bit conservative for what the steel can handle. If you just want to follow the factory bevel angle, it is something between 13 and 15 degrees per side; you can teach your hands how to follow this with an inexpensive angle gauge. They'll develop the muscle memory over time.

As for thinning, you won't need to do it right away if you sharpen lightly and sympathetically. However, it is a more advanced sharpening skill, so I would recommend practicing on something a lot cheaper (You can pick up a Tojiro ITK carbon petty for ~$30 when they're in stock, or something similar for not much more.) so that you do not make the errors that you need to on what I take it is your first nice carbon steel knife. It is totally within the realm of capabilities of an at-home sharpener to thin a knife with the right basic tools, and have it still look and perform as the maker intended (Sometimes better.), but like anything else with sharpening it is a skill that requires some trial and error to figure out what works best for you. If you're worried, though, there are very talented sharpeners like Dave Martell or Jon Broida on this site who can do the work for you when the time comes. 

Hopefully this clarifies...

- Steampunk


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## Keith Sinclair (Aug 4, 2016)

You had it right just sharpen it up when it needs it. As a head Gardemanger went through tons of acidic foods with blue & white carbon steels. Just cut everything with your carbon core knife the edge will take on a patina quickly. You only have to worry about rust before the patina is established.

I grow my own organic tomato's. Love to see how my white steel Carter goes through vine ripe tomato's.:groucho:


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## spoiledbroth (Aug 4, 2016)

Isn't it possible to have rust form on or under patina..?


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## Keith Sinclair (Aug 4, 2016)

Since I cut any thing & everything with carbons a protective patina forms quickly usually a dark grey in a production kitchen cutting hours a day. I never even oiled my carbons because used them all the time. When sharpened creates a thin line of exposed steel but after a couple hours of cutting don't even think about it.

As a home user I oil my carbons all the time. Carbon works best with constant use. sitting around better oil it or it will rust.


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## Johnny.B.Good (Aug 4, 2016)

keithsaltydog said:


> As a home user I oil my carbons all the time. Carbon works best with constant use. sitting around better oil it or it will rust.



I never oil my carbon knives, but the climate in the East Bay is not the climate in Hawaii, that's for sure.

As a home user that doesn't cook large meals for lots of people, I don't cut enough of anything to worry about acidity, etc. I just cut whatever I have to cut, wipe the blade down (or rinse with near boiling hot water from a tap that produces it on demand), then dry thoroughly.


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## Keith Sinclair (Aug 5, 2016)

Yes that works hot water & dry thoroughly. On a mag bloc would get a little corrosion around the neck area little slack with the drying. Biggest problem was my carbon work cleavers at home those suckers would rust if didn't use them for a while. Sold them all now have a couple stainless cleavers that I am happy as a clam with.


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