QUESTION

A woman who is nursing a seven-week-old baby feels that it will be difficult for her to fast while drinking with shiurim (measured intervals). What is the ruling?

ANSWER

First, I would ask whether it would be manageable to drink at intervals of 30 seconds, within the range of opinions for kedei shetiyat revi’it (the time it takes to drink a revi’it; Shulchan Arukh, O.C. 612:9-10; 618:8, Sha’ar HaTziyun 210:11, Aruch Hashulchan 202:8)

In practical terms, it would be almost like doing shots: drink one shot-glassful (about 1.5 ounces), wait 30 seconds, and then drink the next one.

If that is still not realistically manageable, then yes, she may drink normally, without shiurim, if there is a real concern that limiting her drinking in this way will significantly affect her milk supply and thereby compromise the baby’s needs. (Bi’ur Halakhah, O.C. 617; Chazon Ish, O.C. 59:3–4; Siach Nahum 36.)