Long tome ahead!
I’ve dehydrated large quantities of jalapeños and other peppers.
It’s best to wear nitrile or other protective gloves when handling a lot of peppers.
Wash and de-stem the peppers.
Cut them in half lengthwise and remove the core, seeds. The heat is in the core and septae, “veins”.
Set the dehydrator to 120°F, 49°C and space the peppers on the trays in a single layer so they barely don’t touch. You can space them widely if there’s plenty of space in the dehydrator.
Drying time depends on the peppers’ sizes and ambient humidity (the air being sucked in by the dehydrator). Usually 24-48 hours is enough. The peppers will feel hard and brittle when done. If in doubt, give them another 12-24 hours drying.
*Note: Some very hot peppers (e.g. Carolina Reaper) may release irritating fumes while they dry; process them outdoors on a porch or well ventilated room. Also, I’ve had plastic-bodied dehydrators fail and nearly catch fire. Position them away from anything flammable, just in case!
For long-term storage, the best method involves vacuum-sealing mason jars with oxygen absorbers in with the peppers. Many vacuum sealers have attachments to pull air out of mason jars.
Before taking the peppers out of the dehydrator, assemble mason jars and lids (clean and dry), vacuum sealer and packets of 300cc size oxygen absorbers (for quart-sized jars).
Once taken out of the dehydrator, it’s best to seal them up before they pick up moisture from the air. If you want to powder some, this is the time. I use smaller, half pint, wide mouth mason jars for powders. Powdering hot peppers can produce very irritating dust! Wear eye protection and at least an N95 type mask. I have a special “dry blade” for powdering in an old Vitamix blender.
Put the peppers and or powder (packed tightly) into jars, drop an oxygen absorber into each and vacuum seal the jars. With powders, the seal can fail because powder gets sucked up in the sealing process. Pack the powder tightly and leave about an 3/4 inch head space above the powder.
This method can preserve dried peppers for many years, if stored dark and reasonably cool.
Other methods, like storing in airtight jars also work for shorter term storage. Freezing extends storage life. Be sure to put a date on the jars.
Due to capsaicinoids, oily resins in the peppers, I don’t recommend vacuum bags for storage. I don’t trust plastics in this application since it’s possible plasticizers could leach into the peppers. Plasticizers are used to condition plastics and are toxic. If you want to use a plastic vacuum bag, first make an envelope out of aluminum foil to contain the peppers and put that in the vacuum bags before sealing. (I’ve done this with hops.)
As with other vegetables, you can roast the peppers before dehydrating, but they’ll be harder to de-seed, handle. They may also drip juices before drying out some. You can also smoke the peppers outdoors, in a low-fire smoker or grill. Repeat applications using a smoke pistol can also work. However! Smoking means the dehydrator will expel a strong smoky smell; best done outdoors.
Whole peppers can be dried, but take far longer to dry; we’re talking adding days. Thin-walled peppers, like cayenne, Korean can be left whole, but I still cut them in half and remove seeds; it’s easier when they’re fresh and speeds up drying. With very pointy peppers, splitting the pointy tip can help a lot. This area tends to trap moisture, especially in moister peppers like Korean and Thai types.