I had some 4 year old beans I tried to pop, started them 3 weeks ago. 2 out of 3 slowly cracked and tried to put out tails so I planted in promix. I have a cabinet I use for germination and it maintains a temp of 75-80*F, bottom heat. Usually seeds crack within 24 hours and germ in 3 to 4 days. These went 2 weeks, nothing, so I moved them to a window that gets direct sun. A week later one has shown its cots, maybe the top heat from the sun and the changing temps from day to night helped. Hopefully the others will surface.