The Japanese term santoku [三得] means “three virtues,” which has a distinct Buddhist connotation. Somewhere around 1920 or so, this term was applied to a hybrid Western-style knife, manufactured in Japan and constructed with the modern Japanese housewife in mind. Far more recently, the term has come to refer to an approximate blade shape that has gained a large market-share in Western, perhaps especially American, home kitchens. Despite the hype and advertising schemes applied, the knife in question is in no reasonable sense traditional to Japan. No clear figures are available, but it appears that in Japan the santoku has in the last few decades become the most popular knife shape among home cooks.
Of the various knife styles still in functional use in Japan, the santoku is among the most recent, arising from Western influence. In this context, Japanese knife makers begin experimenting with truly double-beveled knives, which had not been used to any significant degree, in culinary knives at least, for quite some time. The first step is simply to copy Western knives for the use of Western and Western-trained cooks. This is where the gyuto comes from, for example — it’s a chef’s knife.
Now speculation must come in strongly, because documentation is scant and ill-researched. It seems that knife-makers and non-professional cooks start noticing this odd (to them) thing, that Western knives are not strictly segregated. A Western vegetable knife isn’t a “vegetable knife” in the sense that it can never ever touch any kind of flesh, but rather a knife that is particularly well-suited to cutting vegetables. By contrast, a nakiri or usuba never touches flesh, ever. (It’s unclear whether this segregation also covered the use of the heel of a deba for heavy herb mincing.) The other thing that happens is that suddenly everyone can feel free to eat meat openly, and in fact all of a sudden it’s stylish and clever to do so. The first chicken restaurant in Kyoto opens around 1880, and by 1900 things like yakitori (grilled chicken on a stick) and teriyaki and sukiyaki and so on are all the rage.
So by roughly 1920 or so, the housewife needs a new knife, one for cutting meat. The thing is, her mother never had such a thing. And knives aren’t cheap. So somewhere along the line somebody says, “hey, ladies! You don’t need all that junk, the nakiri and the deba and all that old-fashioned nonsense. You’re young and hip and chic and Western! You need a Western knife, one that can cut anything! And here you have it!”
What gets sold this way is sort of like an unholy marriage of a chef’s knife (gyuto) and a nakiri. Presumably it was thought that this shape would be reasonably comfortable to a lady who’d grown up with a nakiri, but it was truly double-beveled and curved and pointed like a Western knife and could thus be used effectively for meat as well as veggies. For fish, the deba still reigns, but you can buy cut fish from the fishmonger.
This knife eventually settled down with two principal names: santoku and bunkabocho [文化包丁]. “Santoku” does indeed refer to the three Buddhist virtues (of which there is more than one set), and seems to have been a marketing device: “this knife is thrifty and Japanese as well as clever and Western!” Bunkabocho literally means “cultural knife,” but actually the term “bunka” had in the 1910s-20s a connotation of “clever, modern, Western,” and thus this is the “clever, modern, Western knife!”
It is unclear how and when this new knife supplanted the nakiri, but there can be little question that it has done so. Among serious culinary professionals, the usuba has been partly displaced by the gyuto (French chef’s knife), but the santoku has no significant presence here.
Uses, Advantages and Disadvantages
A santoku is intended to be used as the principal knife in a home kitchen. It is very ineffective for butchering of any kind, including of fish, but it will give at least adequate service when used with the range of vegetables and basic pre-cut meats and fish that the Japanese housewife is likely to need to cut regularly.
The santoku is most effectively used with an exaggerated form of the classic French chef’s knife technique for basic cutting. The handle begins high, the point aimed sharply down toward the board, the tip of the blade resting on the food. In the cut, the handle moves forward and also down, ending with its butt very close to the board, the heel of the blade on the board at the rear edge of the food. Done smoothly, this motion makes the knife dip and swoop, but a closer examination will show that it is not fundamentally different from the standard railroad-engine piston motion of a chef’s knife in classic French cutting, only more rounded.
One advantage of this motion is that the total depth of space used in a cut is rather smaller than with an equivalent-length French chef’s knife. Simply, a santoku allows for a shallower cutting space and board. On a closely-related note, the santoku and its preferred cutting motion maximizes the length of the edge, such that you gain less from a longer edge. In other words, there is very little, if anything, to be gained by purchasing a santoku more than about 7.5" long, whereas a French chef’s knife comes into its “sweet spot” at about 8".
Some users have found that these same qualities make the santoku a superior design for cooks with small hands, but others dispute this point.
The fattish area near the point of the knife — fat by comparison to a chef’s knife, that is — makes it work reasonably well for lifting and moving cut foods, akin to but less effective than the way Chinese cleavers are used as spatulas for cut materials.
The principal disadvantage of the santoku profile is the same as its principal strength: that funny dip-swoop motion and its necessarily efficient use of edge length. In essence, this sets a sort of upper limit on what technical proficiency can achieve. If a beginner can use a santoku with confidence, there is in this sense no such thing as a master with a santoku: there is nowhere to go with skill. One might contrast this against the Japanese professional vegetable knife, the usuba, which is extraordinarily difficult for a beginner but has an enormous potential to shine as the cook’s skill improves.
Concretely, this is all to say that a santoku is fundamentally somewhat inferior to its obvious counterparts, the French chef’s knife and the usuba. However, because it is remarkably easy to use, requires very little space, and may possibly be especially accessible to those with small hands, it is an excellent choice for the casual cook.
Purchasing a Santoku
Most major lines today offer a santoku or an “Asian chef’s knife,” which is usually the same thing. Length should be between 6" and 7.5" (15-19cm). Assuming the purchaser seeks a knife for a casual cook, a knife that will cause no trouble and demand no effort, the ideal characteristics will be light weight, tough edge, easy sharpening, low price.
Weight: a santoku should not weigh as much as an equal-length Western-made chef’s knife. It should feel light and dexterous in the hand.
Tough edge: a knife like this must stand up to a good deal of usage between sharpenings. On a related note, a durable stainless alloy is the best choice here.
Easy sharpening: the knife should run to one of the standard grinding angles, probably 15/15, so that it can be passed through an inexpensive electric grinder like the Chef’s Choice. It should be of a metal that will tolerate this well. For this reason, a “damascus” cladded blade is a poor choice, since the attractive pattern will scratch and grind away too easily.
Low price: in Japan, knives fitting these characteristics can be had for under $30. In America, this is not so simple. Nevertheless, a purchaser should make an effort to stay under about $60, unless non-functional considerations (color, shine, famous endorser, etc.) are significant for the end-user.