fresh kero,,? im using kero i bought 10 years ago. i truked fuel to airports for over 12 years,,,jet fuel is filtered when ever it moves from on tank to another. kero is a highly refined fuel. just not filtered like jet. you can put your kero in a gal glass jug and let it sit over-night and look for crap. then pour it slowley into you flying contanier though a coffee filter in a funnel. you should have a filter in your aircraft too. dont get too anal.