I was looking through some of the recipes in The Good Housewife's Jewell (England, 1596) and came across the recipe below.
To make fillets of beefe or clods instead of red Deare.
First take your Beefe, and Larde it very thicke, and then season it with pepper, and Salt, Sinamon and ginger, Cloues, and Mace good store, with a greate deale more quantitie of pepper and Salte, then you would a peece of Venison, and put it in couered Paste, and when it is baked, take vineger and suger, Sinamon and Ginger, and put in, and shake the Pastie, and stope it close, and let it stande almonst a fortnyght before you cut it vp.
What makes this interesting is that it clearly states that the pie is to be kept for two weeks before eating it. From what I've read recently, the spices called for have anti-bacterial properties (especially the cinnamon), which when combined with the vinegar may kill off any existing bacteria and prevent new growth (I'm still trying to find out just how well spices can do this).
The only other recipe I'd found before like this one is from a similar source, The Good Huswifes Handmaide for the Kitchen (England, c. 1588). It has a similar step of pouring vinegar into the baked pie, but only states that the pie can be kept "a great while."
To make a pie to keep long.
You must first perboile your flesh + press it, + when it is pressed, season it with pepper and salt whilest it is hot, then lard it, make your paste of rie flower, it must be very thick, or else it wil not holde, when it is seasoned + larded, lay it in your pie, then cast on it before you close it, a good deale of cloves and Mace beaten small, and lay upon that a good deale of Butter, and so close it up: but you must leave a hole in the top of the lid, + when it hath stood two houres in the Oven, you must fill it as full of vinigar as you can, and then stop the hole as close as you can with paste, and then set it in the Oven again: your Oven must bee verie hot at the first, and then your pies will keep a great while: the longer you keepe them the better wil they be: and when ye have taken them out of the oven, and that they be almost cold, you must shake them betweene your hands, and set them into the Oven, be well ware that one pie touch not another by more than ones hand bredth: Remember also to let them stand in the Oven after the Vinigar be in, two houres and more.
The common aspects of the recipes appear to be seasoned meat and fat, placed into a crust and baked, and vinegar poured in afterwards. It's also interesting to note that both recipes instruct the cook to shake the pie, assumedly to distribute the vinegar.
This of course leads me to wonder how such a pie would taste, and just how safe (or unsafe) would it be to eat? I'm tempted to make one and see if I can find a lab to test for bacterial levels after two weeks.