Daily Halacha - Can Food Baked Before Shabbat Be Cooked?

Can food baked before Shabbat be cooked?

Just as there is no cooking after cooking, there is no cooking after baking. Therefore, it is permissible to pour hot water from a primary vessel onto coffee, and it is also permissible to add soup croutons to hot soup even in a primary vessel (Shulchan Aruch 318, 5, Yabia Omer 8, 35).

Similarly, there is no baking after baking, therefore it is permissible to place a slice of bread on a hot plate even though it will become toast.

Is it permissible to wash dishes on Shabbat with water heated by a solar water heater?

It is permissible to use a solar water heater on Shabbat for washing dishes and similar purposes, but one should not bathe in water heated by a solar water heater due to the "decree of bathhouse attendants" (Yabia Omer 4, 34).

Is it permissible to wash dishes with water heated by a boiler that was turned on by a Shabbat timer?

One should not use a boiler with a Shabbat timer, even for washing dishes (see Yabia Omer 10, p. 116).

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