Hi,
As a public service, lets have this matter thought out and settled before it is really needed.
I am one who likes to make their gravy from pan drippings. It's just that the drippings from a brined bird can often be too salty. I typically pour most of the roasting pan's liquid into a measuring cup to simply skim away the fat, which also carries salt. I use paper towels to wick the last of the fat on the surface. To the bits still clinging to the roasting pan, I use unsalted stock and wine to loosen and dissolve those bits with my whisk.
If I had not brined the turkey, I would have used the turkey fat to make a roux. For a brined turkey to reduce the salt, I will make a roux from unsalted butter and flour, then incorporate the pan drippings and use stock to dilute to a desired thickness. I cross my fingers and hope the salt may be at an acceptable level at first taste.
If I roasted vegetables (carrots, onions, celery) in the roasting pan, then I add it to the degreased drippings with unsalted stock and use my blender wand to puree the vegetables. If there is enough roasted vegetables, it will be thick enough without roux. The gravy tastes great and nobody detects the vegetables because they were so impregnated with turkey flavor they are undetectable as vegetables. Again, I cross my fingers and hope the gravy tastes acceptably salty at first taste.
If the gravy is too salty, my initial reaction is to dilute it further. I have seen suggestions of simmering potatoes or bread to absorb the salt. First off, I have read enough to know its been independently tested to not really work. Secondly, when you are making gravy, you are at the tail end of meal's prep. Waiting ten minutes for the bread and potato (or whatever) to absorb this salt (if it really works, which it doesn't) isn't very welcome.
A few years ago, Gary and Jazzfood with other LTHr's helped prepare a
Christmas Dinner for the Salvation Army, where the gravy for the roast beef was too salty:
The only slight problem we had all day was the gravy, which was overly salty. This is where it really paid to have a professional chef in the kitchen, when additional water and a bit of lemon juice didn't work, Jazzfood simply surveyed the kitchen pantry, added a food service size can of tomato sauce and, presto, not salty, moreover, a smooth delicious gravy.
Stock and lemon juice (wine, vinegar) I can understand as part of the battery of tools to resolve gravy's saltiness. I don't quite see adding tomato sauce to a turkey gravy. Of course, when you are desperate, you will do what you have to do.
I did see another idea for resolving salty gravy by making another roux with stock, then adding the salty gravy until the flavor is there and the salt at an acceptable level. I guess it is a variation of diluting further, then adding a paste of butter and flour to thicken the gravy.
Somehow I always manage to have a decent gravy. However I am sure for some who may be brining a bird for the first time, this salty gravy may be a surprise. I am also hoping to learn any additional strategies to deal with this pesky problem. When I was a teenager, my Aunt Mary Beth advised to have a can of turkey gravy just in case all else fails. I never bought one.
Regards,