Citizens, this is a delicious, simple and versatile condiment made famous in the Florida Keys.
The Florida Keys are a string of tropical islands stretching about 120 miles off the state’s southern tip, between the Atlantic Ocean and Gulf of Mexico and only 90 miles from Cuba.
They’re known for their supremely laid-back vibe and as a destination for fishing, boating and scuba diving. Key West is famous for Duval Street’s many bars, Mallory Square’s nightly Sunset Celebration and the Ernest Hemingway Home and Museum.
The premier seasoning of the Keys is “Old Sour”, using the eponymous “Key Lime” as the primary flavor base. It is extraordinary with seafood, cooked or raw and a splash in Florida Keys Conch Chowder is traditional.
Old Sour is a sauce used in both Key West and the Bahamas. It is made from an aged (fermented) mixture of key lime (fruit) juice and salt. Of course, key lime juice is also integral to the seminal Keys recipe of Key Lime Pie!
Also known as the Yucatan lime, the Key lime is much smaller and rounder than its Persian cousin, with a thinner, yellowish skin. More tart and aromatic, the juice alone has considerable bite.
The season runs May through August, though the fruit can be found year round. When choosing Key limes, look for brightly colored, smooth-skinned ones that are a bit heavy for their size – they have more juice.
“Conchs” (natives of Key West) use the sauce for a variety of food including to flavor seafood dishes. The sauce may have been developed to preserve lime juice.
Try using it in place of vinegar or citrus juice in salad dressings; or add it to mayonnaise or butter-emulsion sauces.
Old Sour has a salty and acidic flavor and is often made with Bird pepper to add additional kick. TFD prefers this.
As noted in naplesillustrated.com:
The key when making Old Sour is to avoid metal at all costs – citric acid reacts to metal and will affect the fermentation process.
With that being said, squeeze those mini limes with a glass or ceramic juicer, a la that vintage1950s citrus juicer that’s been gathering dust in the china hutch – those plastic citrus squeezers tend to have metal hinges, which can cause problems.
Also, sterilize everything, from the juicer and mixing bowl to the container used to mix the ingredients – if not, prepare for a moldy, spoiled mix.
My version of this classic recipe, in a nod to the Bahamas where the recipe was probably invented (and is MUCH HOTTER than the Florida version!!!) is to use a very optional touch of native allspice.
Citizens, it is absolutely heretical to do this and Conchs may lynch you if you serve them my version – I suggest not telling them and accept their accolades that you make the best Old Sour they ever tasted!
Battle on – The Generalissimo
The Hirshon Florida Keys ‘Old Sour’
Citizens, please note that I can no longer afford to absorb the nearly $1000 per month it costs to keep the site running smoothly, including marketing expenses, etc. There is, however, a solution that benefits us all – one that will help to avoid the only other alternative, which is to add obnoxious ads throughout the site.
Become a Citizen Prime for only $4 per month and receive exclusive recipes, 3 free historic cookbook scans, discounts from TFD sponsors and so much more! For less than the cost of 1 Starbucks coffee, you can keep TFD Nation strong and proud! Details are here.
You can also show your support by listening to our podcasts, liking them, and sharing as you see fit – try them out here.