I read on here somewhere or on another site popping beans in warm areas make the seed think it’s the middle of summer and creates a male by survival encoding. They said to replicate Spring temps and it may pop more females.
Several months ago I did a round of seeds and popped them in the fridge. Then I would take them out place them on the warm areas for several hours including in the summer sunlight on my sink ledge. I would then put the seeds back in the fridge for a few hrs and some days overnight.
So far 5 of the 6 plants are showing female with only one not sure still but appears to be female.
I wanted to give you the information that may or may not help. I will do another run of seeds like this in the future and will post again my results.
Have a great day frons.
First time hearing anything like that ? So basically cold temps higher chances of females ? Warm more males ?
Not sure why it worked or how but the first round has shown all females besides one slow I just wanted to make a note of it for anyone who wants to try it as well. It’s been bothering me that it worked basically, so I posted. Thanks for the reply.
It’s interesting… but with only 6 plants, not particularly conclusive of anything other than good luck. 
Might be worth trying with more in the future, or just repeating the process to see if it happens consistently, I guess. Typically I try to keep my seedlings at 80F while germinating, I thought that was ideal - when you say you popped them in the fridge, how exactly did you do it? The fridge will also tend to suck all the humidity out of everything, so you must’ve had them enclosed somehow, I’m guessing.
I have a cross I am doing and out of 50 I have 6 males. All popped in about 72-75 F.
As I understand it sex of the seed is set at germination, otherwise feminized seed could be reverted to male by certain conditions. Sample size of six is way too small to tell you anything.