Dr Pepper’s (original) secret formula (maybe)
‘Poking through antiques stores while traveling through the Texas Panhandle, Bill Waters stumbled across a tattered old ledger book filled with formulas.’
The Dr Pepper company says this ain’t it. Others think otherwise.
The formula in the ‘Castles’ ledger purchased by Bill Waters contains (among legible ingredients) ‘gentian root, sweet flag root, mandrake root, wahoo bark, cinnamon bark, cardamom, coriander, cloves, diluted alcohol, syrup, glycerin’ and is labeled, ‘D Peppers Pepsin Bitters.’
Like another pharmacy invention, Coca-Cola, Dr Pepper’s secret flavoring formula is the subject of much conjecture.
Time frame and location are all right. More info here and here.
The ‘D Peppers Pepsin Bitters’ page from ‘Castles Formulas’
The birthplace of Dr Pepper: Morrison’s Old Corner Drugstore, Waco, TX
1960 advertisement (top) found via Jon Williamson