Rabbi, If one has a doubt whether he said or not brochoh acharona (shehakol, al hamichya, etc.), does he has to say it “again”? Thanks, RG
For most berachos, where one has a doubt as to whether the berachah was said or not, one should not say it over again.
However, where the berachah is obligated on a Torah level, in cases of doubt one will have to recite the berachah again. Therefore, if a person has eaten his fill in a bread meal, and is therefore obligated in Birkas Ha-Mazon on a Torah level, and he has now forgotten whether he benched or not, he must bench again out of doubt.
However, if he is only obligated on a rabbinic level — he has not eaten his fill, a new berachah is not recited.
Concerning the berachah of Al Hamichyah there is a dispute among authorities as to whether it is a Torah berachah or only rabbinic (see Rabbeinu Yonah, Berachos 32 of Rif; Tur, end of 209). The Rambam rules explicitly that even for a doubt of Al Hamichya, a new berachah is not recited, and this is the halachah.