Food replicators have become ubiquitous across the Federation and beyond and it is no surprise, they are remarkably useful.
The initial food synthesizers used blocks of proteins, carbohydrates and various chemical components to create passible imitations of food however they were extremely limited in what they could produce.
With the advances in transporter technology, the advance to food replicators was a huge leap in the ability to provide food for starship crews and, later, everyone. As long as power was available, food could be produced. This has occasionally led to disaster when power was not available in sufficient amounts for extended periods of time and is why there are emergency rations stockpiled on every Starfleet ship and shuttle, just in case.
Standard Replicators have an extensive library of foods programmed in, a commercial unit may have millions, a Starfleet ship will have billions. The base replicator pattern for a food is made by finding the best example of such food (“the Ur pattern”) and dematerializing it with a transporter, noting the complete arrangement of the food on a subatomic level and allowing it to be recreated with precise accuracy.
In theory, replicated food is indistinguishable from the food the pattern was taken from. However, people dispute that, a significant minority of almost all populations say that replicated food is “flat” in taste, lacking the true complexity of food produced from original materials. A known restriction is that food that includes a significant amount of fermentation is their development of flavor, Kimchi from the Korea region of Terra for example, is difficult to produce as an entirely suitable version via replicator.
While the food produced by replicators mimics the food asked for, it is also enhanced with vitamins, minerals, and other nutritional supplements required by the person asking for the food. Someone with an excellent sense of taste can tell the difference between meals replicated for humans and Vulcans for example as the mineral balance is subtly different. Food for species whose dietary needs may be toxic to other species they are serving with are usually served on color-coded plates and enhanced with a chemical that makes the food taste unpleasant to those who would find it toxic.
Many Starfleet members customize their replicator orders from the simple (“hamburger, no onion, extra pepper”) to the convoluted (“Apple pie, a mix of apples grown on Washington, Terra, and Yarrow Coloney, cinnamon from Ceylon, honey rather than sugar”). The convoluted recipes tend to be shorted to a standardized phrase such as “Apple pie, Conrad Variant.”
There is a subculture that enjoys exchanging and refining replicator “recipes”, so much that it has an entire vast database on OpsNet devoted to such. There are also groups of hobbyists who seek to recreate historical or even fictional foods via the replicator.