The difference between the words 'βαπτίζω' and 'βάπτω' is well illustrated by a recipe for pickles written in the 2nd Century BC by Nicander, a Greek poet and physician. In his recipe, he states that turnip roots can be first dipped [βάπτω] into boiling water and then soaked [βαπτίζω] in a potent salt solution. The dipping is a temporary action, but the soaking changes the very nature of the vegetable. The complete text, in Greek and English, follows below.
ὅτι δ᾽ ἤσθιον διὰ ἀναστόμωσιν καὶ τὰς δι᾽ ὄξους καὶ νάπυος γογγυλίδας σαφῶς παρίστησι Νίκανδρος ἐν δευτέρῳ Γεωργικῶν λέγων οὕτως:
γογγυλίδος δισσὴ γὰρ ἰδ᾽ ἐκ ῥαφάνοιο γενέθλη
μακρή τε στιφρή τε φαείνεται ἐν πρασιῇσι.
καὶ τὰς μὲν θ᾽ αὕηνον ἀποπλύνας βορέῃσι,
προσφιλέας χειμῶνι καὶ οἰκουροῖσιν ἀεργοῖς:
θερμοῖς δ᾽ ἰκμανθεῖσαι ἀναζώουσ᾽ ὑδάτεσσι.
τμῆγε δὲ γογγυλίδος ῥίζας （καὶ ἀκαρφέα φλοιὸν
ἦκα καθηράμενος） λεπτουργέας, ἠελίῳ δὲ
αὐήνας ἐπὶ τυτθὸν ὁτὲ ᾿ν ζεστῷ ἀποβάπτων [dip]
ὕδατι δριμείῃ πολέας ἐμβάπτισον [soak] ἅλμῃ,
ἄλλοτε δ᾽ αὖ λευκὸν γλεῦκος συστάμνισον ὄξει
ἶσον ἴσῳ, τὰς δ᾽ ἐντὸς ἐπιστύψας ἁλὶ κρύψαις.
πολλάκι δ᾽ ἀσταφίδας προχέαις τριπτῆρι λεήνας
σπέρματὰ τ᾽ ἐνδάκνοντα σινήπυος. εἰν ἑνὶ δὲ τρὺξ
ὄξεος ἰκμάζουσα καὶ ὠμοτέρην ἐπὶ κόρσην
ὥριον ἁλμαίην αμυσαι κεχρηόσι δαίτης.
The Deipnosophists, Volume II, Book IV, 133c-133e
But they also ate as an appetizer turnips done in vinegar and mustard, as Nicander plainly shows in the second book of the Georgics
; for he says:
Of turnip and cabbage, in truth, two families appear in our gardens, long and solid. The latter you wash and dry in the north wind, and they are welcome in winter even to the idle stay-at homes; for soaked in warm water they come to life again. But the other, the turnip roots, you cut in thin slices, gently cleaning away the undried outer skin, and after drying them in the sun a little, either dip [βάπτω] a quantity of them in boiling water and soak [βαπτίζω] them in strong brine; or again, put equal parts of white must and vinegar in a jar together, then plunge the slices in it, having dried them off with salt. Often, too, you may pound raisins and biting mustard-seeds with a pestle and add it to them. When cream of tartar forms, and the top grows more and more bitter, then 'tis time to draw off the pickle for those who seek their dinner.
The Deipnosophistae of Athenaeus, Volume II, Book IV, p. 114-115
Translation by Charles Burton Gulick