Ideally, you can start feeding your 4 to 7-month-old babies with baby food jars. In other words, your munchkin must be old enough to eat course and chunkier food items. And apparently, most store-bought food jars contain solids. Also, do not ever feed your baby directly from the store-bought jars. Transfer the contents onto a plate or bowl, as per your convenience, and then feed them. If you have just started new food items in a jar for your baby, they may refuse for once due to the new texture of the food. However, don’t force it. Try it next week, and if the baby continues to refuse, consult your doctor.