Remove the stems from the peppers and most of the seeds.
Vacuum Sealed Method
Toss with the salt and garlic and vacuum seal. Allow the mixture to ferment at room temperature for two weeks.
I like to ferment the peppers in a warm room where I have a dehydrator going in the summer which helps speed up the process.
Glass Jar Method
Grind the peppers to a paste in a food processor with the garlic.
Transfer the pepper paste to a jar, add the salt and water, stir, screw on a lid and allow to ferment for two weeks.
Cooking and Finishing the Sauce
Toast the cumin seed and grind to a powder.
Pour the fermented pepper-garlic mixture into a non-reactive pan, adding the water, vinegar, and maple syrup.
If you use the ground pepper method you will skip adding the water as it was added prior to fermentation.
Bring the pot to a boil, turn off the heat, then carefully puree the mixture in a blender until smooth-ish.
Pureeing hot sauces can be dangerous as it causes pressure to build in the blender. Make sure there's a way for air to escape through the lid before pureeing so the top doesn't blow off.
Taste the sauce and adjust the seasoning for salt. I usually add an additional ½ teaspoon or so.
Transfer the sauce to a jar, cool, and store in the fridge. If it was fermented for the full two weeks it will last a long time. It can likely be water-bath canned but I haven't tried it yet.
Video
Notes
Maple syrup is my first choice for sweetening this sauce, but honey will work fine too. Maple sugar works too, but is more expensive than syrup.
This can be a good recipe for dark maple syrup or syrup of lower quality as it's used as a sweetener instead of all by itself.
To speed up fermentation, you can add a few scrapes of fresh ginger, or a piece of sauerkraut.