I'm not sure if it's the same for jalapeños, but supposedly shishitos from the same plant can vary in heat https://en.wikipedia.org/wiki/Shishito https://en.wi

I'm not sure if it's the same for jalapeños, but supposedly shishitos from the same plant can vary in heat https://en.wikipedia.org/wiki/Shishito https://en.wikipedia.org/wiki/Shishito I grew Apache chilis and there was definite variance - one year the green fruits were napalm, the next they literally tasted like bells (until they turned red...)