Often a common question among newcomers to Japanese knives is the decision to make between carbon and stainless steel. Which should you choose? There are a few points to consider when making your choice.
The most commonly used Japanese Carbon steels are Aogami (Blue), Shirogami (White). The most commonly used Japanese Stainless steels are VG10, Ginsan, AUS8. The hybrid powder stainless steels with the best of both worlds are SG2/R2, ZDP189, HAP40.
This is the key difference between carbon and stainless knives. Carbon steel knives require higher maintenance than stainless steel knives, as they lack chromium content which gives stainless knives their corrosion resistant properties. By definition, a stainless steel is a steel than contain more than 10.5% of chromium.
If you cut produce and leave a carbon steel knife wet on the cutting board, expect rust spots to appear within a matter of minutes. This is not the case for stainless steel. Some carbon steels like Shirogami (White) steel for example, will develop rust quicker than Aogami (Blue) steel, even though they are both carbon steels. This is due to the high purity of Shirogami, and the added elements in Aogami.
As a result of this lack of chromium (which make stainless steel stainless), these knives will also develop what’s called a patina, or a discolouring of the blade due to oxidizing of the steel. This is completely normal, and will produce blueish, purple hues across your blade that cannot be removed short of polishing the blade. Further reading about the patina can be found here.
Once this patina is fully developed, which may take several weeks of use, this will act as a protective barrier from elements which may rust your blade. It is good insurance against leaving your blade wet for a few minutes on the board.
2) Edge retention
On the whole, you will find that carbon steel will retain an edge longer than most stainless steels. Carbon steel has a finer grain structure, and as a result of being forged, the steel will hold an edge for longer than a softer stainless steel.
However, there are exceptions to this point. There exists stainless steels that have more carbon than carbon steel knives, that are also fully stainless. These are referred to as powdered stainless steels, and SG2/R2, ZDP189, and HAP40 are the most prominent of these steels used in knifemaking. These are widely considered to have the best of both worlds, with fantastic edge retention and stainless properties.
3) Ease of sharpening
From our experience, carbon steels will sharpen up easier, faster, and to higher levels than most stainless steels. Shirogami, being the purest carbon steel, will sharpen to a scalpel like edge with ease. Aogami is very similar to sharpen, but will require a small amount of extra effort to reach similar results.
Softer stainless steels like VG10 and AUS8 can be trickier to sharpen than carbon steels, but this also depends on the quality of the heat-treatment of the steel.
The harder powder stainless steels can be the most difficult to sharpen. Due to their high hardness, it is recommended these are sharpened with at least a 500 grit stone to speed up the initial burr forming process.
The final point to consider when choosing a carbon or stainless steel japanese knife is the price difference. This price difference will be mainly due to the amount of time required to finish a particular piece, as well as the materials used.
Knives using Shirogami and Aogami carbon steels can be found relatively cheaply, $80-$150) if the process to finish these knives is not very time consuming. Obviously, some knives made using Shirogami or Aogami can be extremely expensive as the time required to finish these pieces to perfection is high.
VG10 is increasing in price and popularity, so it can be difficult to find good, authentic VG10 knives for less than the cost of carbon. Some seemingly reputable knife shops in Australia and the world will source knives made using Chinese “VG10” equivalent, or outright deceive you by saying the steel is from Japan when it is not, and sell these knives cheaply, passing them off as “Japanese”. Beware of these imitations.
The SG2 and powder stainless knives are generally more expensive than the rest of the other steels, starting at around $300 for the Takamura SG2 Gyuto and rising from there. These are often the best quality and value for money out of the stainless steels.
There are many factors that contribute to whether a knife will suit your requirements or not. If you don’t mind some extra care and maintenance, and would prefer to stick to a lower budget, then an entry level carbon steel knife will be your best choice.
If you’d rather spend the extra money and would rather a lower maintenance knife, SG2 or a powder stainless steel will be a great choice you will be sure to love. Just take care around cutting hard objects as to not chip the blade, and you’ll be enjoying your knife for many years.