Like the other guy said. As long as everything downstream from (after) your .22 micron filter is sterile, you have nothing to worry about. .22 micron will filter out bacteria and anything else you need to worry about. The filter is the key and that honestly is all you need.
Just be careful with the vacuum filter so as not to break the filter. If you watch and you suddenly see the liquid move through the filter much faster than before, the filter probably burst. At that point you must extract the oil from the vial and refilter it then toss the vial.
A little biology 101 for you:
- "By calculating the amount of space required to house this “needed stuff,” the
lowest theoretical size for a free-living prokaryotic cell [a single celled bacteria] is estimated to be a sphere of 250 to 300 nm in diameter (primary source 227)." -
Harvard
- the vast majority of bacteria are much larger than that theoretical lowest size limit above
- viruses are often much smaller of course, but viruses can't live outside their host, so even if some how you had a virus floating around your house that go caught up in your oil, it would die pretty quickly, rather than replicate and cause a dangerous growth like bacteria would.
- bacteria can live outside a host, replicating themselves and forming large colonies to the point where you can see the colony with the naked eye. Viruses cannot survive outside the host. Maybe it is a good idea to avoid homebrewing while sick/around a sick person just to be safe.
- a .22 micron filter is 220 manometers, which is small enough that it will filter out all bacteria.
- additionally the BA will also prevent bacterial growth in the even something somehow got through.
- lastly, post brew you obviously never use unsterile needle tips to dip into a vial. Never ever ever do that.
So basically the filter is the key. That's it. You should never heat the oils to disinfect them, just heat enough to dissolve the raws.
Be patient when filtering, it is a slow process. You are pushing (or pulling) viscous oil through a bunch of tiny 220 nanometer holes, that is a high pressure activity. Be careful and go slow so you don't burst the membrane and have to start all over.
Print our your brewing instructions and use a pen/pencil to cross off the steps as you work through them to avoid missing anything.