POPCORN POPPER Yes it really does work :o While this might sound like a strange bit of gear to roast coffee in it is probably the easiest way of all the cheapy methods to have a bash. My Popper was under $20 of ebay and came with a 'free' bag of popcorn 🙂 Not all poppers are equal, some will roast way to fast and they can be a little prone to early onset failures. There is also a heap of people who have played with poppers to extremes if you want to follow these couple of links to some OTT mods. Insert Frankenpopper and other links....... The popper I have runs around 6-10 minutes depending on the quantity of beans used but generally 80g works. Experiment with your standard one between 60-100g for a start. Beer is purely optional but in 30 degrees it helps find your inner roaster 8). Most important bits are spoon 'handle' for a little agitation while starting, popper and the sieve for cooling. Timer is more of a check as you have fairly limited control over the roast. 
Inside the popper chamber. The vents visible are important as airflow is used to circulate the beans and prevents scorching the lower ones and leaving the uncooked ones on top. 
80g of beans approximately 1/2 a cup by volume if you don't have scales. Side note not all beans are the same size and do vary in density this also plays a factor in perfecting the roast down the track. 
The airflow as mentioned above will keep the beans going, I find that until the beans start to swell and get to FC a little additional stirring helps a lot to keep the beans in motion. Another technique I have seen used is to hold the popper on a bit of an angle initially to help the movement of beans. 
Slight colour change before FC from Green to Pale Yellow, notice the volume change between the photo above. By this stage the beans have reduced in density to circulate by themselves. 
Nearly at SC (second crack) beans have further increased in volume and colour is approaching what you would typically recognise as Roasted Coffee. 
Finished and cooled. You will notice I have circled up two beans in particular these are actually 'defects'. Depending on the beans there is a myriad of different defects that occur in Green and Roasted Coffees but these are worthy of another entire book. Quakers, splits, chips, hollows (the circled ones), scorching, tipping ...... Its a long list. Best thing to do is sip it and see. 
If your roasting with this method is under say 4 or 5 minutes then it is less than ideal so time to look at modding your popper a little ;D The key thing to me is roasting is fun and a learning thing whatever method you use, there are no right and wrong answers it is part science part technique and a lot of practice and refinement.
