I find it varies. Even though I've only ordered about 10 or so flavors so far. The best thing to do with any liquid is to try them when you get them (after a good shake) and if your
sense of smell is up to par, give it a good sniff. If it's decent, vape it. If not, give them a couple of weeks.
Just as examples:
In my first order I chose Chocolate Fudge Bavarian Cream and Fried Apple. Both from that order were ready to go out of the box. The Fried Apple had the high tone of biting into a fresh apple slice with the warmth of cinnamon. Over the past few weeks, the cinnamon is much more prominent now.
From my second and third orders, only the coffee was ready to go. The others (Melon Explosion, Cotton Candy, Green Apple, Candy Cane, Very Berry, CheeseCake, 2nd order of CF Bavarian Cream) needed anywhere from a few days, to 2-3 weeks. Melon Explosion was good from the beginning but was watermelon heavy, it's more fresh cantaloupe-like blended now.
Cheesecake I'm finding to be the most stubborn, it had a milk like smell to me at first, it's making progress, but not quite ready
yet. Might need a month or longer to mature methinks. Very Berry had various levels of pleasantry. At first freshly berry like, in the middle of aging, meh (probably due to my taste buds going wacky at various times), & after the full couple of weeks, very nicely melded. So much so I had to keep my hand glued to my PV or my bf would try to grab it.
But this is just my opinion and how timing works for me right now.