How this word tastes to you will surely be strongly affected by your religious background. For many people, it’s an unfamiliar word, or at most the name of a herb that may be used medicinally to treat coughs, fevers, and similar symptoms, and may be used (though not commonly in North America) in cooking to give a slightly bitter minty flavour. But hyssop plays an important role in the Judaeo-Christian tradition, though not all members of the Jewish and Christian faiths will be equally familiar with it.
For me, as someone who has sung in choirs, it immediately brings to mind the “Asperges me,” a text based on Psalm 51 that is sung in the Latin mass in conjunction with the act of sprinkling holy water:
Asperges me, Domine, hyssopo et mundabor,
Lavabis me, et super nivem dealbabor.
Miserere mei, Deus, secundum magnam misericordiam tuam.
(Listen to a stirring setting of this by Cristóbal de Morales.) In English, this is translated as
You will sprinkle me, O Lord, with hyssop and I shall be cleansed,
You will wash me, and I shall be washed whiter than snow.
Pity me, O God, according to Your great mercy.
The hyssop’s central association is indeed with bearing water or other holy fluids – and with sacrifice. At the time of the Passover, it was with a hyssop branch that the Israelites were told to sprinkle the blood of the sacrificed lamb on the lintel and doorposts of their houses. It was also used in other rites of purification, with the blood of a sacrificial dove or with water. And in the Christian tradition, add this: According to the gospel of John, when Jesus on the cross said he was thirsty, he was offered a sponge soaked in vinegar on the end of a hyssop stick. You can see that this herb, and thus this word, comes with a solemnity, a flavour of sacrifice and purification, for those who have encountered it in this context.
What is the word, anyway? Where does it come from? The hy may make you think it comes from Greek, and indeed it does, via Latin: ὕσσωπος hussópos. But Greek seems to have borrowed the word from Hebrew ezob. Interesting how the voiced/unvoiced difference affects it: ezob seems more to me like a name for a desert herb; hyssop – pronounced “hissup,” by the way – has a whispering quality to it, like a breeze, like waters, like a whisper in a basilica, the voice of a purifying spirit. But, then, that’s also because of the associations I have for it.
But there is another thing: as sometimes happens, names shift (chalcedony is another example of this). The plant referred to in the Bible is probably not the plant we now call hyssop. It was more likely Syrian oregano or a similar plant. But that fact is not meant to cast aspersions on the taste of this word. Indeed, this word – or its object – is what will cast aspersions: it will asperge, which is to say, sprinkle. And purge, and wash, and make white as snow. Yes, that’s what hyssop sounds like: pure snow, with the breath of the spirit passing over.