- One who eats food less than a kazayis(the size of an olive) or drinks a beverage less than the volume of a revi’is (86cc/2.9 fl. oz. – 150cc/5 fl. oz.) recites the initial blessing but not the after-blessing (Shulchan Aruch and Mishnah Berurah210).
2. Some say that if the person ate a whole item — such as a complete grape or pomegranate kernel, or a whole bean or granule [but a pitted olive is not considered a whole item] — even if it was not the size of a kazayis does require an after-blessing on account of its stature. It is therefore proper to be careful and not eat a whole item if one will not be eating the full amount of a kazayis (ibid. and Kaf HaChaim ad loc.).