You could make a few of them when you have time to then stick them in the fridge untill you are ready to use them. Do them up in bottles and then when they are done you can just put a cap on it to seal it up and store. They should last a couple of months.
"Yes, I am a pirate two hundred years too late. The cannons don't thunder there's nothin' to plunder,
I'm an [under] forty victim of fate, Arriving too late, arriving too late."