We are continuing in siman 2, where the Chayei Adam is discussing melachos performed with a shinui or ki’lachar yad. We left off discussing the definition of shinui, and learned that the result must be less than optimal, or even if the result is the same, the performance of the action is in some way more laborious or difficult. For example, if a person needs to turn on an electrical appliance, if it is life-threatening or there is an immediate danger, one should not waste precious time on doing a shinui. If it is life-threatening but not immediate such that there is no time concern, it is preferable to minimize the melacha by performing the melacha through a shinui. Thus, if one uses their knuckle rather than their finger, the result (turning on the machine) is the same, but the process is more uncomfortable. Therefore, most poskim consider using one’s knuckle as a shinui for turning on machines or pressing buttons. Some poskim do not consider it a shinui, since the difficulty is minimal, but the majority of poskim consider it a valid shinui.
There are scenarios where the shinui is not in the melacha itself, such as putting a pot on the stove to cook with one’s weaker hand. Since the shinui takes place before the melacha, as the melacha is the cooking not the placing, to the point that if one takes the pot off the stove before it is cooked to the level of maachal ben derusai, they are not chayav. Therefore, some poskim hold this would not be a valid shinui. An example of a valid shinui when it comes to cooking would be to turn on the fire with a shinui, but once the fire is on, it is hard to come up with a valid shinui.
Parenthetically, when it comes to bishul, it would actually seem as though putting something on a fire is a grama of sorts, since it is the fire that “performs” the actual melacha of cooking, while the person only placed the item. However, part of the chiddush of meleches machsheves is that putting something in a situation which takes advantage of the forces of nature is considered melacha.
Summary
A shinui has to be in the melacha itself
and has to be something that either makes the result less than optimal,
or hinders the performance of the melacha in some way.
