I'm going to start by doing it wrong! I was making quite a lot of flavoured coffee and didn't have big enough pans (or enough of them). I used a plastic container and lined it with greaseproof paper.
Using a glass measure pour 1oz of the flavouring oil for every 3lb of beans. It is best to use freshly roasted coffee beans but I just warmed the beans in the oven whilst I measured out the oil.
Place the warm beans in the container and using a metal spoon dip into the oil and then stir into the beans. Keep repeating this process until all the oil is used up.
The finished beans have a slight sheen to them showing that the oil has been evenly distributed.
Cover with some tin foil but allow the coffee to breath for about 4hours. This will help the beans absorb the flavour.
I cut myself a scoop using a milk bottle. I weighed out 8oz and then marked the bottle to make sure I got the same portion size each time.
I used another milk bottle cut to make a funnel shape so I could scoop and pour into the bags. Here I used foil lined bags but there are many suitable bags available online.
Here are my bags off coffee all waiting to be sealed and labelled.
I used a cheap heat sealer to create an airtight seal and then folded over the top and stuck on a homemade label - Overthwarts Productions in my case!