ive kept bud in vacuum bags before when i was buyin like a qp, if it is really good and cured where it keeps its form fairly well then it can be done but you definitely dont want to suck all of the air out because it can squish the shit out of it if you dont watch it... overdoing it will make it look like it was put in a compactor, like brick weed... i just sucked most of the air out when i did it