DHARMA Ranch Composite was a salad dressing and one of the many DHARMA branded food items found in the Swan pantry. It apparently had an unnaturally long shelf life - meaning that it did not need to be refrigerated after opening. It could keep up to seven years at room temperature (according to the label). ("One of Them")Real-life ranch dressing has a buttermilk or sour cream flavor and the consistency of mayonnaise.
A jar of it was used for target practice by Locke and Michael when Locke was teaching him how to shoot. This jar, however, was misspelled, saying "DHARAMA Initiative" where it should have said
DHARMA Initiative." ("The 23rd Psalm") Another jar was stolen by Hurley for his food stash which was later found by Sawyer. ("One of Them")
Ranch Dressing was invented in 1954 by Steve Henson of Hidden Valley Ranch in California. Hensen and his wife Gayle ran a "dude ranch" near Santa Barbara and served the dressing to their guests. Hensen sold his rights to the dressing in 1972 for 8 million dollars.