It's probably the mix of catsup and vinegar...at least it is in my recipe:

Brunswick Stew (Old South Recipe)

1 4-5 lb. chicken or stewing hen
2 lbs. boneless beef stew meat
1 lb. onions
3 lbs. potatoes
2 15 oz. cans of tomatoes and their juice
2 1 lb. cans of cream style corn
1 1 lb. can baby lima beans or same amount frozen
1/2 to 1 bottle of catsup (a 14 oz. bottle)
1/3 to 1/2 bottle Worcestershire Sauce ( a medium bottle)
1/3 to 1/2 cup vinegar
1/3 to 2/3 cup fresh squeezed lemon juice
2 to 4 t. Tabasco sauce
2 t. salt
black pepper to taste

Cook hen and beef in a large pot with water to cover. Cook until well done and meat leaves the bone easily. Pick meat from bones and shred into small bits [or fine grind in a food processor]. Do both the beef and chicken in this manner. This step can be done a day or two before; refrigerate the broth and remove the fat when it has hardened on the surface.

You will need a very large pot. I use my pressure canner w/o the lid.

Put onions and peeled potatoes in a grinder, or dice by hand, or chop small in a food processor. Add all the vegetables and seasonings to the broth and meat. By adding the larger amount of catsup, W. Sauce, vinegar, and lemon juice you will have a more tangy stew. These amounts can be adjusted to your taste. Cook over low heat, stirring occasionally, for 2-3 hours. Smash up the cubes of potatoes as you stir. Serve hot or cool, pour into containers and freeze. Yields 5-6 quarts.

Note: you can add a pound of cubed pork to the meats when cooking them if you desire. Small shoe peg corn can be used in place of the creamed corn if you prefer.

I have two Brunswick stew recipes that are wonderful winter comforts. One is a more Southern traditional Williamsburg Brlunswick with chicken; the other has beef added. I'll take a look at both recipe's and get back if there is an unusual ingredient. I have to say that I don't think either recipe has a hidden secret ingredient. All are pretty normal/natural and wholesome. For my own regular beef stew, however, I add a very tiny bit (1/8 tsp or so) of allspice. I add other dried herbs as well, but none that would add that bit of sweetness that you describe. That bit of allspice really adds a little bit of hidden something to a beef stew; and you might consider it for your Brunswick stew -- I'm sticking with my original Brunswick recipes, however (it's not a chili cook-off after all). A really good Brunswick stew is just what history intended it to be. I hope this helps and that you find that special hidden ingredient.
Annie1971

My friend who seems to know all things in the Williambsurg area says that the secret is squirrel.
But she may be just yankin' my chain....

Thank you both and correction to what I typed. I wrote Pork but meant to type beef.

Teresa you may be right with what you posted as to what I am tasting. Annie, I would love to see your recipes also especially the Williamsburg one as I am in VA. Thank you for the tip on allspice.

LOL! Linda you were posting as I was posting. No she is not yankin' your chain! That is the way they made it in the day in VA but that is not the way it is made now (at least not the way that I make it). Some may still do that but not me and I'm fairly certain that the Ruritans don't do it that way either.

There is no catsup or vinegar in traditional Brunswick stew. If that's what you're tasting it isn't Brunswick stew.
Annie

I love Brunswick Stew. The first time I had it was when we lived in Durham, NC and always got it with the barbeque at our favorite place. I use the recipe in Fanny Farmer Boston Cooking School, though I only use chicken, not the squirrel or rabbit suggested.

Brunswick Stew
Vary this famous Southern dish in many ways. It is often made in huge quantities for an out-of-doors get-together and can be made of squirrel and rabbit as well as stewing chicken. Sometimes pork spare-ribs and pieces of stewing beef are cooked with the chicken, and other vegetables are added, such as green beans, okra, diced potatoes and peas.

Cover with boiling water 1 stewing chicken, cut in pieces
Cover and let simmer over low heat for 45 minutes.
Add 2 teaspoons salt
Cover and continue cooking until tender (about another 45 minutes). Take out the pieces of chicken. Remove the bones
and cut the meat in l-inch pieces. Put back in the kettle and add
l can condensed tomato soup, 8 tomatoes or l cup canned tomatoes (I use diced tomatoes)
I onion, sliced thin
l cup green lima beans
3 potatoes, sliced thin
l tablespoon sugar
Salt and pepper

Cook until the beans and potatoes are tender.
Add I cup corn, cut from the cob, or canned whole-kernel corn
1/4 pound butter
Cook 5 minutes. Serves 6 to 8.

the key to good brunswick stew is left over barbque or even using a rotisere chicken...remove the meat and add later as it is already cooked...cook down the hogs rib cage after a pig roast or carcass from what ever was cooked. flavor the broth with seasonings( i.e. bay leaf, onion, etc. to your likings...in our neck of the woods, typically, it will have tomatoes, limas, corn, additional bbq sauce...get the true flavor out of your bones and skin and go from there..bz

Brunswick Stew

1 no. 2 can tomaoes
1 T olive oil
1 1/2 T shortening
2 white onions
2 cloves garlic
Heart of Celery
1 lb mushrooms
1 pint chicken broth
1 no 2 can creamed corn
1/2 bunch parsely
1 T bell pepper

Cook tomatoes in olive oil until thick. Make reux with flour, shortening, onion, garlic, celery, add broth, tomatoes, corn, green onion and mushrooms. Cook 1 hour add 1 fat cooked and boned and cut up chicken.

there are two Brunswick Stew factions...

In the deep south, Brunswick Georgia is said to be the home of the real stuff ... which uses "one pig's head, feet, liver and heart". In Mrs Dull's 'Southern Cooking' you are cautioned to thoroughly clean the pig's head and feet. It does use catsup.

The other "original home of Brunswick Stew" is Brunswick County Virginia and here's a great recipe

http://www.tourbrunswick.org/Stewrecipe.htm

In this one you are instructed to "catch your Chicken" .. thowing in some veal shins and 'middling with the rind'.

Both are cooked in a huge iron pot.

have fun

Squirrel meat is a touch on the sweet side so maybe?

Linking a recipe from Colonial Willamsburg cookbook. Squirrel is indeed referenced as being original to the recipe.

Here is a link that might be useful: Colonial Wmsbg Brunswick Stew Recipe

Thank you all for your help! I know that old recipes definetly used squirrel but to the best of my knowledge, I have never eaten it. I don't know how authentic their recipe is but it is good. I'm looking forward to trying out some of these ideas. Thanks again.

My recipe is mostly like the link ci_lantro posted from Colonial Williamsburg restaurant, though I always like to add a couple of bay leaves when I'm cooking a slow simmering stew like this. It seems to add just the right subtle flavor. Also, if the tomatoes seem sharp, a pinch of sugar or a couple of carrots help balance the flavors. I also like to use fresh corn cut off the cob. That adds a brighter sweetness than canned or frozen corn (but of course, not exactly in season when I like to make the stew...).

Theresa and Beezee, I've never made the stew with catsup or bbq sauce, but the idea sounds yummy!

The only other thought I have on this, is I've seen with many traditional recipes, people will use skinless chicken breasts instead of whole chickens in an effort to cut the fat or because that's what they're used to, but it's the whole chickens with skin and bones and dark meat that really brings that full flavor through.

We're getting a bit of a cold breeze tonight. If it stays that way, I know what tomorrow's dinner will be! Thanks for the idea dixiedog.

Can't actually say about Williamsburg.. Here in the South it never has beef in it - that's when it becomes just plain old stew.

The meats here are always chicken and pork. The vegetables are always corn and limas, sometimes tomatoes, orka and potatoes.

There is no barbecue sauce or ketchup, but the seasonings may be like those in bbq sauce.

And never have I ever heard of mushrooms in brunswick stew. That, like the beef, goes back to being just beef stew.

It's like America's Test Kitchen finally said, true Southern cornbread has no flour or sugar in it. But lots of people who use those still put the "southern" label on it.