Why knife skills matter

 Sometimes when reading a recipe you come across words like chop, dice, mince and slice. If you are making a puree of broccoli soup you might wonder what's the difference how I cut my onions since they're all eventually going into the blender anyway. In short, the answer is that it matters quite a bit.

 Most soups and sauces call for a mirepoix in the beginning, which is essentially a mixture of some aromatic vegetables which build the foundation of flavor for the final product. Paying close attention to detail here really is important because it can have a profound impact on the flavor at the end. Minced onions might taste burned if they are included in a mirepoix with big pieces of carrot and celeriac. Conversely, rough chopped vegetables might give too much of a raw vegetal taste to a sauce.

 Recipes should indicate how to cut the vegetables for the mirepoix, but if they don't a good rule of thumb is that they should be somewhat uniform in size and shape. You might want to cut hard vegetables like carrots and parsnips slightly smaller than softer ones like onions and celery.

 Now the reason why I titled this post "Why knife skills matter" is because how you get the mirepoix cut is probably more important than why you cut it to begin with. The First Commandment of mirepoix cutting is "Thou shall not use a food processor". Even a brand new one with a razor sharp blade will tear and crush the vegetables instead of chopping or dicing them. This is really important because vegetables naturally have a high water content. If they're crushed the water weeps out of them immediately, contributing off-flavors which won't cook out.

 Think about waking up in the morning and having a delicious glass of celery juice. Is this the flavor that comes to mind when you taste Coq au Vin or Ratatouille. These dishes both depend heavily on how the vegetables are cut. No machine can do it properly.

 Hand cut vegetables also make a big difference in things like coleslaw. Machine chopped cabbage is so watery that even a thick dressing will result in soupy coleslaw.

 Try chopping, slicing and dicing by hand the next time you make something that calls for vegetables to be cut and you will see what I mean.