If someone is in sofek whether they made a bracha or not, poskim say you can be make the bracha “b’hirhur” and then continue to eat. However what if the person did this then realized they are for sure they didn’t make a bracha before, may they make it now or is it a problem since they already were m’harhar the bracha.
Answer:
When one has a doubt over having made a berachah or not, poskim advise making a berahcah in one’s mind (a “mental reading”), without articulating the words, which is a valid berachah according to the Rambam (Berachos 1:7).
However, the principle halachah does not follow the Rambam, and this advise is only given by way of a lechatchilah practice: in a situation where a full berachah cannot be made, one should at least think the berachah in one’s mind.
However, even after making this berachah “in thought,” if one remebers that one did not made the original berachah, one can (and must) articulate the berachah out loud, because we rule (not like the Rambam) that a berahcah that is not spoken out is not valid (see Shulchan Aruch 62:3; 185:2; 206:3).
Although concerning reading the Shema the Shulchan Aruch (62:4) writes that one “fulfills one’s obligation” with a mental reading (see Peri Megadim, who explains that although one does not fulfill the rabbinic enactment this way, it is fine on a Torah level), the Mishnah Berurah (62:4, based on Rabbeinu Yonah, as cited by the Taz) writes that this should not be understood literally, but rather that the obligation is not fulfilled, yet the mental reading is nonetheless virtuous.
Therefore, after making a mental berachah, and then remembering that one didn’t make the original berachah, a new berachah can and should be made.
