Written by the team of Rabbanim from the Orthodox Union:

Rabbi Eli Gersten , Rabbi Yaakov Luban and Rabbi Moshe Zywica

Rema (Orach Chaim 583:2) writes that some are careful not to eat egozim (walnuts) on Rosh Hashanah. This is because the gematria (numerical value) of the Hebrew word “egoz” is the same as the numerical value for the word chait (sin). Additionally, nuts cause an increase in phlegm, which can disturb one’s prayers.

Magen Avraham (583:4) points out that according to this second reason, all nuts, even those that are not referred to as “egoz,” should be avoided. Mateh Efrayim (583:3) extends this minhag to include not eating beans (or peanuts).

However, Be’er Moshe (3:97) writes that ground nuts (other than walnuts) that are cooked together with other ingredients as part of a recipe do not pose a concern. This is because the two reasons mentioned above do not apply.  

• Other nuts (e.g.  almonds, filberts) are not referred to as egoz. Their numerical value is not equivalent to chait.  

• When cooked as part of a recipe, the taste of the nuts is not so apparent, and you need not be concerned that it will cause an increase in phlegm.  

He also mentions that some poskim permit eating all types of nuts, including walnuts during the day meal on the second day of Rosh Hashanah. Presumably, because by this point we have already heard the shofar, and there is less of a concern that the phlegm will cause a disturbance.

However, others write that because of the association with chait, you should refrain from eating walnuts the entire aseret yimei teshuva (from Rosh Hashanah through Yom Kippur).