Question: At what age should children begin waiting between meat and milk?
Answer: The Shulchan Aruch (OC 343:1) writes that parents mustn’t feed their children non-kosher food. Thus, one can’t even feed a baby meat and milk together. How long children need to wait after eating meat before eating milky foods depends primarily on their age.
The Rema (OC 328:17) writes that very young children have a similar halachic status as a choleh shein bo sakanah (a bedridden patient), who doesn’t need to wait long between eating one meal and the next. Thus, R’ Shmuel Wosner (Shevet Halevi 4:84) and R’ Moshe Stern (Be’er Moshe 8:36:4) write that one can feed babies milk just after they’ve eaten meat, though the baby’s mouth should be cleaned first (See Chochmas Adam 40:13).
R’ Mordechai Yaakov Breish (Chelkas Yaakov YD:16; 17) writes that children only need to wait an hour until they’re nine. R’ Ovadia Yosef (Yabia Omer 1:YD:4; 3:YD:3) writes that if older children want to have a milky meal, they only need to wait an hour. He writes that one shouldn’t, however, utilise this leniency to give them chocolate treats, etc.
Other poskim disagree, however, writing that parents are obligated to begin educating children as soon as they are old enough to understand the concept of milky and meaty foods. R’ Moshe Stern writes that children should begin waiting an hour after eating meaty foods when they are 3 years old.
R’ Moshe Sternbuch (Teshuvos Vehanhagos 1:435) writes that children should begin waiting three hours when they are about five or six and wait (about) six hours when they reach nine or ten.
The Aruch Hashulchan (YD 89:7) writes that older children should wait longer than an hour unless they are weak.In conclusion, babies can be fed milk after meat providing their mouths are clean. As children mature, they should be trained to wait longer. Certainly, children who are weaker or have health issues shouldn’t be encouraged to wait too long.