Whiskey and Gin Tours

From the US Embassy website:

Alcohol

Residents and non-residents over 21 years of age may bring no more than one liter of alcoholic beverages (beer, wine or liquor) to the U.S. duty free. You may not mail alcoholic beverages to the U.S.

From Elsewhere:
Putting alcohol in your bag
Other federal rules will apply depending on whether you intend to fly with alcohol in carry-on or checked bags.

For starters, there's a size limit for bottles in your carry-on. The Transportation Security Administration requires liquids over 3.4 ounces to be packed in a checked bag, but exceptions are made for liquids above that size that are bought after you clear the security checkpoint.

If you're checking a bag with alcohol in it, the Federal Aviation Administration allows 5 liters per person of unopened bottles with alcohol by volume over 24% to 70%. You can pack more than that if the alcohol by volume falls under 24%.

The FAA doesn't allow bottles with alcohol by volume over 70% in checked bags or carry-ons.

Obviously, you'll pay duty on anything more than 1L per 21+-year-old in the family.
Duty free shop is the easy way to make sure your bottles are well protected, as they'll be in your care, but checked into luggage is the other option. Normally I'm a backpack-only traveller but I've got a hard-shell bag for Scotland, specifically because we plan to return with hooch.

Couple of places in Edinburgh https://www.scotchwhiskyexperience.co.uk/

and https://www.cadenhead.scot/

both on the Royal Mile

You can bring in as much alcohol as you want. However, only the first liter is duty free.

https://help.cbp.gov/s/article/Article-190?language=en_US#:~:text=There%20is%20no%20federal%20limit,that%20you%20comply%20with%20the

My husband and I brought back a total of 4 liters of whisky (Arran Distillers) and gin (Barra Distillers) from Scotland in 2019. We declared it and the immigration official didn't bat an eye; no duty imposed. It was in our checked luggage. The important thing is that you declare what you have. As long as the official considers it an amount for personal use (not for resale) you'll be fine. If you fail to declare and our caught consider the whisky gone along with a portion of your bank account.

This article has some very good information on distilleries near St. Andrews including Lindores Abbey Distillery and Eden Mill Distillery. It's nicely written, too - it makes me want to head to a few of these. :)

https://www.theexperiencestandrews.com/us/blog/whisky-distilleries-to-visit-near-st-andrews/

Thank you all for your responses. I ended up booking the Scottish Whiskey Experience while we are in Edinburgh and a tour at the Kingsbarns Whiskey Distillery and a separate one at their sister company, Darnley's Gin Distillery, both of which are six miles south of St. Andrews. When we get back home, I will post a trip report about our experiences at each. Again, many thanks.

Jim

Just remember in Scotland it is spelled whisky. No e.

As opposed to uisge which comes out of the tap, and in large parts of the country is the sort of water people would pay good money for if it came in a bottle.