# The physics of slicing cheese **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 16, 2017, 5:10am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612 "2017-12-16T05:10:22Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [December 16, 2017, 5:10am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/1 "2017-12-16T05:10:22Z")
Hard-ish cheeses, like supermarket cheddar, are hard to slice with a knife. I know this to be true from experience, but I don’t know why. But the bigger puzzle to me is why, when you slice a nice square block of supermarket cheddar with a wire cheese slicer (like [this](https://www.amazon.com/gp/product/B00UVKK2TI/ref=s9_acsd_newrz_hd_bw_b1DNY_c_x_w?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=merchandised-search-5&pf_rd_r=H6JF2EH1R9S3S1B4D53H&pf_rd_t=101&pf_rd_p=6fc432a6-4ef5-55a8-b04b-f1f03bcd023b&pf_rd_i=289760)) the sliced face of the cheese soon becomes convex, and gets more convex as you remove more slices. Each slice looks even from top to bottom, but the block of cheese looks distinctly not square any more. Can anyone tell me why this happens? Does it have to do with the roller? Or some arcane principle about semi-solid masses and steel wire? ---
**Author:** ![Telperion](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telperion/32/509_2.png) [@Telperion](https://boards.straightdope.com/u/Telperion)\ **Post date:** [December 16, 2017, 5:40am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/2 "2017-12-16T05:40:55Z")
My experience is that [this](https://www.amazon.com/Norpro-Stainless-Steel-Cheese-Slicer/dp/B000SSYY88/) kind of slicer cuts square blocks straight, but wedges curve uphill. I don’t know why. ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [December 16, 2017, 6:36am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/3 "2017-12-16T06:36:48Z")
I just cut some cheese. Does that count? It was pretty loud too. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [December 16, 2017, 6:41am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/4 "2017-12-16T06:41:20Z")
Oh, I thought that was the dog! ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [December 16, 2017, 7:18am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/5 "2017-12-16T07:18:35Z")
It was the dog! ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [December 16, 2017, 7:27am UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/6 "2017-12-16T07:27:18Z")
Quit feeding that dog cheese. ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [December 16, 2017, 9:28pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/7 "2017-12-16T21:28:45Z")
1. The difficulty in cutting cheese with a knife arises from two main factors: friction and deformation under pressure. Cheese has a relatively high coefficient of friction (though I have been unable to find exact numbers for particular cheeses), and a knife presents a relatively large, flat surface area in contact with the cheese. Consequently, friction between a knife blade and the cheese surface is high. A wire (or a cheese knife with holes through the blade) presents less surface area than a normal knife, and therefore is less impeded by friction. Cheese is also plastic, deforming under pressure, which raises two additional hindrances to cutting: the cheese in the path of the cutting edge is compressed, becoming slightly harder, and the force you want to exert is limited by the fact that you don’t want to squish (ahem, as distinct from “squeeze”) the cheese. 1. Plastic deformation is likely also involved in the answer to your main question, the curvature of a sliced cheese. Pressure from the wire causes the block of cheese to deform, bulging outward ahead of the wire. The roller follows the bulge, so the slice remains even, but it is cutting farther away from the original plane of the cheese block. When the pressure is removed, not all of the deformation reverts, so you’re left with curved surface on the block. IANAC(heeseologist), but this is my best guess. ---
**Author:** ![Tim\_R.Mortiss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim_r.mortiss/32/142_2.png) [@Tim\_R.Mortiss](https://boards.straightdope.com/u/Tim_R.Mortiss)\ **Post date:** [December 16, 2017, 10:02pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/8 "2017-12-16T22:02:05Z")
I agree with the friction theory, and also with the deformation theory, but I think we are looking at \*elastic \*deformation here, not \*plastic \*deformation. The same problem occurs when machining metal. The force of the cutting tool compresses the workpiece elastically, so when you cut where you think you should be, you are actually cutting in the wrong place. After the force is removed, the workpiece/cheese springs back, elastically, and you have a deformed surface. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [December 16, 2017, 10:04pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/9 "2017-12-16T22:04:26Z")
I have a set of serrated Henckels steak knives and they are totally the best thing I’ve ever found to slice either hard or soft cheeses. I have no idea why – probably the way they’re serrated, and a blade width that is fairly normal but much smaller than a typical kitchen knife. Whereas even the best utility or chef’s knife does not, probably for the reasons given above. ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [December 16, 2017, 10:07pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/10 "2017-12-16T22:07:34Z")
> [@Tim\_R.Mortiss](#): > > I agree with the friction theory, and also with the deformation theory, but I think we are looking at \*elastic \*deformation here, not \*plastic \*deformation. Well, it’s some of both. Elastic deformation is reversible, while plastic deformation is not. If the deformation in the cheese were all elastic, I think the remaining surface would be concave, rather than convex as described by the OP. It’s possible the OP got convex/concave reversed, as that’s a pretty common error. In that case, elastic deformation would be dominant as you suggest. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [December 16, 2017, 10:17pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/11 "2017-12-16T22:17:59Z")
> [@Tim\_R.Mortiss](#): > > I agree with the friction theory, and also with the deformation theory, but I think we are looking at \*elastic \*deformation here, not \*plastic \*deformation. The same problem occurs when machining metal. The force of the cutting tool compresses the workpiece elastically, so when you cut where you think you should be, you are actually cutting in the wrong place. After the force is removed, the workpiece/cheese springs back, elastically, and you have a deformed surface. That seems odd, unless incredibly terrific force was being applied, as metals tend to have a very high elastic bulk modulus. Most types of steel, for example, have a bulk modulus 80 times that of water, which in everyday terms is damn near incompressible. ---
**Author:** ![Snowboarder\_Bo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowboarder_bo/32/229_2.png) [@Snowboarder\_Bo](https://boards.straightdope.com/u/Snowboarder_Bo)\ **Post date:** [December 16, 2017, 10:19pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/12 "2017-12-16T22:19:48Z")
Elastic, plastic, deformation, reformation, friction… all cheese should henceforth just be [laser cut cheese](https://www.youtube.com/watch?v=EpTmbr8SUOs). ---
**Author:** ![Tim\_R.Mortiss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim_r.mortiss/32/142_2.png) [@Tim\_R.Mortiss](https://boards.straightdope.com/u/Tim_R.Mortiss)\ **Post date:** [December 16, 2017, 11:04pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/13 "2017-12-16T23:04:48Z")
> [@wolfpup](#): > > That seems odd, unless incredibly terrific force was being applied, as metals tend to have a very high elastic bulk modulus. Most types of steel, for example, have a bulk modulus 80 times that of water, which in everyday terms is damn near incompressible. Oh, engineering steels are very much compressible, maybe not in “everyday terms,” but certainly to a scientifically significant extent. If they weren’t, we wouldn’t have such phenomena as work hardening and residual stresses, and wrought iron would be no better than cast iron. Rather important points in precision metalworking. ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [December 19, 2017, 9:22pm UTC](https://boards.straightdope.com/t/the-physics-of-slicing-cheese/804612/14 "2017-12-19T21:22:54Z")
> [@wolfpup](#): > > I have a set of serrated Henckels steak knives and they are totally the best thing I’ve ever found to slice either hard or soft cheeses. I have no idea why – probably the way they’re serrated, and a blade width that is fairly normal but much smaller than a typical kitchen knife. Whereas even the best utility or chef’s knife does not, probably for the reasons given above. These guys? [![](https://images-na.ssl-images-amazon.com/images/I/51VvBhucO5L._SL500_AC_SS350_.jpg) ](https://images-na.ssl-images-amazon.com/images/I/51VvBhucO5L._SL500_AC_SS350_.jpg) I have those also and agree with your findings re: cutting the cheese.