Bacon jus is collected from the drippings of cooked bacon. At work after cooking the bacon in the oven I place the par-cooked bacon in a perforated insert on top of a deep (4-inch) hotel pan. I let it sit there for a while, at room temp, until the dripping is done. I then put it through a sieve into a bucket, letting the drippings sit at room temperature for a few hours until it has settled. I then place it in the fridge over-night. The next day I scoop up all the bacon fat from the top (about 90% of the drippings), and collect it for further use. At the bottom will be my gelatin like bacon jus. This jus will be very salty, so when you use it there is no need to add salt. It's good for mixing in soups or sauces, I will collect it over time until I have enough to do something with it. It can take a while, as with 10kg of bacon I will get maybe 2 cups of jus (if I'm lucky).
If you are doing this at home simply make sure to put the drippings into a small container, so that there can be a good sized layer of jus at the bottom to scoop up. If the layer is too thin (your collecting bucket too wide) then it will just stick to the fat and be hard to separate. If you don't cook the bacon (or par-cook it) in the oven, simply save the drippings from the pan.
IrlChef - 2018-02-05 14:04:54:
That is not JUS. Jus is a french term for gravy. What you are describing is bacon fat. the fat you scoop off the top is grease
Also a chef in real life - 2022-03-18 10:00:02:
I have to disagree Irlchef. Although "jus" is indeed a French term, and technically the meaning of the word "jus" is "a thin gravy or sauce made from meat juices" You're not wrong here, but I feel "jus" is still the right term for what this juice from cooking off bacon is. It is seasoned and complete as it is and I damn sure would dip a "french" dip sandwich in that delicious smokey jus. The English language is just like that, a word in another language is the closest thing to what we need for something and we sort of slide the meaning a bit to suit us. Anyway, I did a search for "bacon jus" and this is what came up and I'm happy about it.