Why can we do some melachos for eating on Shabbos but not others?

Question

I learned that certain melachos are permissible on Shabbos in the course of eating or for the purposes of eating. For example, the question of borer in light of "derech achilah"/"derech melacha" is discussed here. It seems that certain permissible forms of food preparation, such as making a salad, are also permitted for this reason. (If not--if these were permitted because there is no melacha involved--I would wonder why some stipulate that the salad needs to be made shortly before eating. And, more generally, it seems clear that some of these permitted forms of food preparation, such as peeling vegetables, do involve what would otherwise be considered a melacha.)

If this is the case, and if we are in fact more lenient on many melachos because of derech achila, then why wouldn't cooking on Shabbos be allowed for the same reason? Although it is obvious enough that cooking is stringently prohibited on Shabbos, a secular Jew recently asked me this question, and I didn't know how to answer.

Answer 1

A general idea used throughout Shulchan Aruch is that The Torah does not forbid "derech achilah". This means that if through the normal act of eating, which is from the point of lifting the food until it is chewed and swallowed, you happen to perform something that can be called a melachah, that is generally not forbidden.

For instance, grinding is one of the melachos. While chewing food in the normal act of eating, you are indeed grinding it up. But, since it is "derech achilah" the Torah obviously did not forbid that kind of grinding.

Cooking is not "derech achilah". One's mouth is not hot so that if you put raw food into it, it will become cooked before you chew and swallow! :)

Since cooking happens outside the actual eating process, it has no aspect that would fall under the permit called "derech achilah".

Also, the allowances for various amounts of time before the meal, in preparation of the meal to perform borer and tochein, is allowed because these acts are just considered an "early form of the soon to be eating process." This is opposed to borer or grinding for storage, which obviously cannot be called an early part of the eating process.

This idea is only valid because borer and tochein do take place during eating anyway; so doing some of it early is the same thing. Cooking however, as we said above, does not happen at all during the eating process. see Tur, Beis Yosef, and Shulchan Aruch 321.

By the way, the Pri Megadim in 321 points out that we do not grind spices (like fresh pepper balls) even if done right before eating, because it is not considered a true food, but rather something that prepares the other food for eating.

I hope this helps. :)

Answer 2

Here's my take on it:

Borer is the act of sorting (anything, not just food). Bishul is the act of cooking. Both are prohibited on shabbos. Then there's an act called eating, which is (obviously) permitted.

When you "sort" food in a permitted way (as @sam mentioned in the comments), then this is no longer considered an act of borer, but rather an act of eating:

1. Ochel mitoch p'soles (taking food that you want out of whatever you don't want) - because if you want to eat something, you pick it up and eat it.
2. For immediate use (or in very close proximity to the meal) - because this shows you're doing it for the sake of eating, not for the sake of having your things sorted.
3. B'yad (with your hand - or at least, not a specialized tool) - because eating is done with your hands or simple cutlery; you don't typically eat with specialized tools.

Now that the act is one of eating, and you've made it clear you're not interested in the sorting aspect of your actions, it's perfectly permissible.

None of this is true of cooking, though, because the act of cooking is inescapably prohibited on shabbos. You can't apply the rationale of "I'm not cooking; I'm just eating", because you are cooking, even if you're also eating.