We are beginning siman 8, where the Chayei Adam discusses bishul achar bishul regarding a davar lach. The Chayei Adam discusses a case of recooking a fully cooked item, and avoids discussing an item which is partially cooked, known as maachal ben derusai. If something is cooked to a minimum such that it is no longer raw and would be eaten in extenuating circumstances, it is considered cooked to the threshold of maachal (the food of) ben derusai. (Ben Derusai was a known bandit who was always on the run. He would cook his food minimally in order to avoid remaining in one spot for too long.)
- Cooking food from raw to maachal ben derusai is certainly considered bishul, because it has changed its status. However, seeing that most people would not eat such a food unless it is extenuating circumstances,
- bringing a food from maachal ben derusai to mevushal kol tzorcho (fully cooked) arguably should be bishul as well.
- Once a food is mevushal kol tzorcho, there is a concept of mitztameik veyafeh lo, that even after being fully cooked a food continues to improve by being left on the fire.
- Bishul achar bishul regarding a davar lach will depend on the state of the food. If the food is anywhere between maachal ben derusai and mevushal kol tzorcho, we are machmir for bishul achar bishul to cook it further.
- This is true with a davar yavesh as well.
