Knives: why a harder blade holds its edge longer
Razlika između nemačkog i japanskog noža nije u imenu nego u dve cifre: procentu ugljenika i tvrdoći po Rockwellu.
A knife that cannot cut through a ripe tomato is not a bad knife. The bad thing is that for seven years it traveled in the drawer along with the forks, washed in the machine at 65 degrees and never once saw a stone. Steel remembers each of those moves.
U radnji se, međutim, ne prodaje održavanje nego blok sa dvanaest komada, po ceni po kojoj bi se kupio jedan pošten nož. Šest komada iz tog bloka nikada neće izaći iz drveta. Kupili smo takav set pre nego što smo naučili šta piše na sečivu, pa je ovaj tekst delom i račun za tu grešku.
Rockwell is the only number on the box that means anything
Sve ostalo na ambalaži je marketing: forged, professionally, damask. Damast je, uzgred, samo sloj mekšeg čelika presavijen oko jezgra — ukras, a jezgro radi posao. Ono što stvarno određuje kako se nož ponaša jeste sastav čelika i tvrdoća merena po Rockwell C scale (HRC).
It is a European standardX50CrMoV15: half a percent of carbon, 15 percent of chromium, some molybdenum and vanadium. It is hardened to 56 to 58 HRC. JapaneseVG-10it has about one percent of carbon and the addition of cobalt, so it comes out at 60 to 61 HRC. SG2 powder steels go over 63. A difference of five degrees on that scale sounds insignificant until you notice that one knife calls for stone every month and the other twice a year.
| Čelik | Carbon | Tvrdoća | Angle to the side | Gde je jak |
|---|---|---|---|---|
| X50CrMoV15 | oko 0,5% | 56–58 HRC | 20° | bone, pumpkin, negligence |
| AUS-8 | about 0.75% | 57–59 HRC | 15–18° | jeftin ulaz u japansku geometriju |
| VG-10 | oko 1,0% | 60–61 HRC | 15° | fish, vegetables, thin cut |
| SG2 / R2 | about 1.4% | 63–64 HRC | 12–15° | drži oštricu najduže |
Hardness is not a quality rating but a character description. Softer steel bends, harder steel bends. One forgives you, the other teaches you.
Tvrdo seče duže, ali oprašta manje
The carbon in the structure builds carbides — tiny hard grains that work like microteeth on the very edge of the blade. The more there are and the harder they are, the longer the edge stays an edge. The price is brittleness: at 61 HRC the blade does not bend but breaks. One swing through a chicken bone or one chop on a glass board is enough to leave a half moon on the edge that cannot be returned with a honing steel.
Uz tvrdoću ide i geometrija. Nemački nož ima leđa debela 2.2 to 2.5 mm i blago zaobljen trbuh, pravljen za ljuljanje po dasci. Japanski je na 1.8 to 2 mm, ravniji, pravljen za povlačenje unapred ili unazad. Ako sečete tehnikom ljuljanja, santoku sa ravnim profilom će vam delovati nespretno — nije loš, nego ga držite pogrešno.
The sharpening angle is the third part of the same story. Twenty degrees per side gives an edge that lasts, fifteen gives an edge that goes into the meat without pressure. You can sharpen the same knife to 12, but it will hurt you on the bow that retained the soil in the head. In our country, twenty degrees is taken for sharpening, and that is why the Japanese knife comes back sharp to the touch and dull in practice: its geometry has been eaten away.
Tri noža rade devedeset odsto posla
Boss knife from20 do 21 cmdo everything that has mass: meat, cabbage, pumpkin, onion. Shorter than 18cm starts to force you to cut in two strokes.Petty od 13 do 15 cmis one that will actually be in the hand — peeling, garlic, small fish, quartering figs. The third is serrated,22 do 25 cm, and you don't sharpen it, but change it every few years.
Santoku od 16,5 do 18 cm je alternativa šef nožu, ne dodatak njemu. Nakiri, pravougaoni nož za povrće, najpotcenjeniji je komad u celoj priči: ravna ivica seče do daske po celoj dužini, pa se glavica luka raspadne na kockice bez onog poslednjeg nepresečenog sloja koji vas uvek sačeka.
U radnji se, međutim, ne prodaje održavanje nego blok sa dvanaest komada, po ceni po kojoj bi se kupio jedan pošten nož.
What is not seen in the shop istrn— extension of the blade inside the handle. A full mandrel runs through the entire shank and is seen as a strip of steel between two plates; the half-thorn stops halfway and that's where, after a few years, the handle starts to wobble. The rule for checking is simple: grasp the knife at the point where the blade enters the handle and let it swing on your finger. If it tips over, you'll have wrist fatigue after twenty minutes of cutting. Handle materials, stabilized wood and micarta withstand moisture without cracking; varnished wood cracks in the first year, and smooth plastic slides as soon as the grease gets in.
Postoji i cela kategorija koju evropska kuhinja gotovo ne poznaje: single-edged Japanese knives, poput jangibe za sirovu ribu ili debe za rasecanje. Kod njih je samo jedna strana pod uglom, a druga je ravna ili blago udubljena, pa nož sam skreće u rezu. Za tanko sečenje sirove ribe nema mu ravnog. Za sve ostalo je nepraktičan, a oštri se drugačije i gotovo isključivo na kamenu — zato ga ne kupujte kao prvi japanski nož.
For fish you need a flexible blade of16 do 18 cmwhich follows the spine. If you chose the right fish at the counter according to the rules in the text on how to recognize itsveža riba na ribarnici, don't ruin it with a stiff, rib-jumping chef's knife. Forpršutis the reverse of the rule: a long, narrow, fully rigid blade of 28 to 30 cm and a cut that pulls, not pushes. And when the meat goes on the grill, the pieces that the butcher keeps for himself —bavette i flat iron— they are looking for a cut transverse to the fibers, which does not work cleanly with a knife duller than 58 HRC.
Ono što nikad ne uđe u set
The first question that no one asks in the shop: is the bladekovano ili isečeno iz table. Forged is made from a piece of steel that is heated and shaped, so it is thicker at the handle and lighter at the top. Cut from sheet metal, it's the same thickness from heel to toe, it's lighter and cheaper, and it's plenty for most kitchens — but it feels like a tool in your hand, not a knife. The difference in the price of the same steel for those two procedures goes up to two times.
Drugo je hump, ono zadebljanje između sečiva i drške koje se na nemačkim noževima spušta sve do pete. Izgleda kao kvalitet, a u praksi znači da poslednji centimetar i po sečiva nikad ne dodirne kamen. Posle nekoliko godina oštrenja tu ostane ispupčenje koje smeta pri sitnom seckanju. Grbina koja staje iznad pete, ili je uopšte nema, taj problem nema.
The third is a sander. It is found in every major market, usually in a series with keyholes, and this is where the fate of the 60 HRC knife is decided. One question is enough: how many degrees does it sharpen. If the answer is that it doesn't matter, take the knife back — it will be returned to you sharp to the touch and dull in operation, with a bit of geometry that no one returns afterwards.
Daska je deo opreme koliko i nož. Drvo i mekana plastika su jedini prihvatljivi izbor; staklo i kamen unište ivicu iz prvog poteza, a bambus je tvrđi nego što izgleda i tupi brže od oraha. Mašina za sudove je najbrži način da ubijete i sečivo i dršku: deterdžent nagriza čelik, para razdvaja drvo od trna.
And one entry that no one recommends out loud: a used knife fromugljeničnog čelika, the gray one that catches the patina and must not spend the night wet. It is easier to harden, sharpens in two minutes to #1000 and cuts better than most stainless for three times the money. Just wipe it off before you leave the board.
Nož se ne bira po broju komada u bloku nego po tome koliko ste spremni da ga održavate. Ko neće da vidi kamen dvaput godišnje, neka ostane na 57 HRC i biće mu bolje.
Questions & answers
short and to the point- Which is better, German or Japanese knife?
- Nijedan nije bolji uopšteno. Nemački na 56-58 HRC prašta kost i nemar, japanski na 60-61 HRC seče tanje i duže drži oštricu, ali se krza. Ako u kuhinji ima kostiju i smrznutog mesa, uzmite evropski.
- Na koliko stepeni se oštri kuhinjski nož?
- European at 20 degrees per side, Japanese at 15. The same knife sharpened at 12 degrees cuts better, but its edge slips on harder vegetables and onions that have retained their soil.
- How much does an honest chef's knife cost?
- For X50CrMoV15 with full mandrel 6,000 to 12,000 dinars, for VG-10 from 12,000 to 25,000. Under 3,000 dinars, steel is usually not even listed, which is enough information in itself.
