I give up. How (what method) did you dry age the hind quarter for 21 days? I never get that many dry (low humidity) days in a row. I envy you! And I would like to learn without having to waste a hind leg of venison. Skipglo may also want to know!
I live in VA and we rarely get the conditions right for this opportunity. I haven't hung a deer in 5 seasons and was only able to hand this one b/c of a cold snap near the end of the season, so it is a rare treat.
I hang in my garage, the whole animal, skin on. Even temperatures, good air circulation, in a shaded area that is pest free is best. Before hanging on a gambrel is inspected the carcass, trimmed back excess belly skin remove the tenderloins. You may leave the head on or not - I have been removing heads for CWD testing, taking the tongue and inspecting for sinus bot flies - YMMV
Wash the cavity with water, dry it, then vinegar, then rub with salt to help create a cuticle. Prop the cavity open. I run a fan and a dehumidifier to keep the air moving. Conditions do have to be "just right" - ideally, temperature under 40 degrees and humidity under 50% - and you have to be ready to process on relatively short notice if the weather dictates. Inspect daily for any off-odors or bacterial growth - mold is not a bad thing, it can be cut away.
Temperature spikes to 50 or so during the day are okay as long as they are short and the meat is out of direct sunlight (and warming) - persistent temperatures too high will result in spoilage. The temperature of the meat is more important to monitor than the air temp. If ambient temperatures dip below 28, the aging process will be slowed and if it really takes a dive into the single digits, will stop altogether - and skinning a frozen animal is NO FUN. Meat will not freeze at 32, so "frozen" solid will occur when temps are very low for a couple days.
Hanging skin on slows the drying time down and also reduced the amount of meat that is lost when processing. The skin will come off very easily after a week of hanging. I've let deer go as long as 30 days and the result was incredible. Test for texture by firmly pressing your thumb into the inside of the leg. When the meat springs-back more slowly and a slight depression remains, the meat is aging well and the texture will be exceptional.
When you've determined that your animal is aged long enough or conditions require it's time to process. Remove the skin then sanitize your area - process as usual. As you butcher, trim away any cuticle (hard dried skin) which should only be the cavity, part of the neck and inner hindquarters, and any shot-through areas. Inspect as you go for any irregularities.
I am a professional chef and restaurateur and I learned this process from an Icelandic certified game butcher, chef and dear friend. We have aged everything from woodcock to elk with exceptional results. A $50 used side-by-side fridge/freezer served as an aging locker during the years we had a duck lease on the Eastern Shore. I've never had better Canada goose on the table after 3 weeks of hanging with feathers on and guts in. The Europeans have been doing this for 100s of years - good cooking techniques still apply. Unless we're fortunate enough to have a cold locker, conditions are not always favorable, locations vary and and each animal is different. Continuous observation is key to watching the process unfold - having a mentor is helpful. Happy to answer any questions - PM me. It has been a gustatory journey of discovery over the last 30 years with many amazing meals.