"The heat is in the seeds"
One of the most common pieces of disinformation that I've noticed many customers and businesses regard as accepted fact is that the heat in chile pods resides in the seeds. I've seen businesses place this on their websites, and had many customers tell me that they don't eat chile seeds because they are "too hot". This is simply not true. The vast majority of capsaicin (the naturally occurring substance in hatch green chile that provides its heat) is found in what is referred to as the "veins" of the chile pod.
When you break open a chile pod, you will see long vein-like strings of meat running lengthwise along the interior of the pod. In mild hatch green chile, these are almost completely white with the occasional hint of yellow coloring. This discoloration is the naturally occurring capsaicin. When you take a step up the heat ladder to medium-hot hatch green chile, you will notice the veins have a more noticeable streak of yellow. This noticeable increase in yellow/orange discoloration of the vein continues on up to X-Hot in which the entire vein is a yellow/orange color. A good rule of thumb is "the darker yellow the vein, the hotter the chile". Although there is still some naturally occurring capsaicin in the flat sections of the chile-pod's meat, the vast majority of it is found in the vein. When green chile is roasted, much of it is spread throughout the pod when cooked, leading to that unmistakable Hatch Green Chile flavor.
So, we've covered the meat and veins, the seeds must be hot too right? The answer is no. Surprisingly, there is little to no capsaicin in chile seeds. One might notice a slight bit of warmth when eating them, but this is just because they have come in contact with the veins and meat of the chile during roasting. Most New Mexicans actually remove the seeds when processing their chile before freezing. When there are seeds in the green-sauce of a restaurant here, its looked at as the "lazy" way of doing things. So its always best to remove the seeds, they definitely aren't what make your chile hot.
We hope this helps clear up any misconceptions you've had about hatch green chile! Stay tuned for Hatch Chile Myth #2 "The skin keeps the heat in".