Pepper vinegar?

Not long ago, on the way back home from a conference, we stopped for lunch at a great restaurant in Richmond VA (Comfort--thanks again for the rec last year, Janet from Richmond!).

Condiments on offer included "pepper vinegar," a seemingly simple bottle of vinegar with a variety of chile peppers in it. It was fabulous, especially on my husband's pulled pork sandwich. When I expressed interest in how it was made--what kind of vinegar, etc--our good-natured waiter told me that the chef happily shared any and all recipes EXCEPT this super-secret one!

I can't seem to find any guidelines for this in any of my cookbooks. Do any of you have ideas? I'm so clueless I wouldn't even know what kind of vinegar to use--cider? White wine?? Plain old white??? Are there any food safety issues, or is the vinegar acidic enough to deal with them?

I've recently planted a variety of peppers that I'm hoping to experiment with later in the season. I am, of course, thinking of the brilliant Will Owen pulled pork preparation....

[Cinnamon]

When making the kind of thing described in this terrific old thread, are we talking fresh hot peppers or dried hot peppers?

When I worked in a BBQ pit down south I would make my pepper vinegar by taking 1:1 vinegar and water (cider, malt, or white vinegar- it's up to you how complex you want it to become) and bringing to a boil with assorted whole peppercorns, a little sugar, and a very small amount of pickling spice. After is simmered for five minutes I taste it and when it's just right, I would funnel it into bottles or jars stuffed with a mix of peppers. Some jars hotter and some less so. After it sits for a few weeks it was ready to serve. This recipe leads to more complex flavors, but less acidity, than when you use pure vinegar, so it is more of a flavoring sauce for BBQ, roast meats and poultry, veggies, etc.

There are different ways to make pepper vinegar, but I use my mother's method which is very simple.
Use a clean or sterilized narrow-necked bottle, and fill with peppers of choice. Birds-eye, tabasco or a mixture are fine. Cover with apple cider vinegar and let sit for a couple of weeks. Add more vinegar as it is used.
You can heat the vinegar before pouring over the peppers, and I make a slit in the peppers which makes for a hotter product.
We always served this with vegetables as well as barbecue.

Yes, it's that simple. I boost the heat by making a pepper puree (2 T of kosher salt & a handful of chilis) to add to the bottle with the whole peppers & vinegar. The salt & acidity are great preservatives, though I guess you could keep it in the fridge if you're terribly concerned about food safety. I use cayennes & tabascos, mostly, but "sport peppers" (a small, hot, yellow-green variety) are very common.