Mon-Fri 8:30a-5:30p   Sat 10a-4p EST 404-752-6715 HABLAMOS ESPAÑOL

ACityDiscount - Restaurant Equipment and Restaurant Supply ACityDiscount - 45 Anniversary

Difference Between A Pre-Mix and Post-Mix Soda Dispenser System

As an owner of a bar or restaurant, you know without a doubt where your highest profit center is.  That is of course in your drink selection and your ability to dispense at a high and efficient rate. You depend on these machines to function reliably and count on them to keep your customer base happy and coming back. If you are planning to buy a soda dispenser, you need to know which machine will perform the best under your foodservice businesses' conditions.

There are plenty of decisions that should be made when you are in the process of buying your carbonated beverage machine. One of which is its placement within your dining area or kitchen; should it be featured prominently in a common area, or in a customer-restricted area? Will it be operated solely by the patrons or your employees? These are crucial questions to answer when trying to determine what level of quality should go into the machine that you are contemplating. 


A Pre-Mix System has three major components that make the machine unique. They are a carbonator, a CO2 tank, and the ever-essential bag of pre-mixed syrup. You will commonly find these setups at smaller stores, carnival concession trailers and county fairs. Most of the time they are for operations that do not have an existing water line installed. The ready-to-drink beverage syrup comes in large metal containers or cannisters. Once the pressurized CO2 gas applies itself to the top of the soda, the drink begins its journey through the machine through a dip-tube. To make the temperature correct, there is generally a cold plate situated above the ice bin. This cold plate is the last stop for the liquid before it exits the machine. This simplified method only requires a CO2 tank and ice to work.

A Post-Mix System is a bit more involved. A post-mix fountain beverage dispensing system is defined by delivering a heavy concentrated beverage base and a diluent for the concentrated syrup to a dispense nozzle, adding one or more of colors, flavors and any additives to the beverage base and diluent to provide a completed carbonated beverage, and delivering this drink into a cup for service to a customer. This type of machine will always house the diluent separately from the concentrated syrup. The concentrate pump works in conjunction with a diluent pump to deliver the concentrate and diluent into a valve for mixing and dispensing of the final product with a higher level of consistency every time.


Soda machines come in a wide assortment of sizes. While you can purchase a one-nozzle unit, 6 to 8 individual dispensers on one machine is most popular design. There are options for up to 24 at a time.


The output of these machines are largely dependant on the size of the nozzle that is fit on to the spout. The larger the nozzle, the more volume you will be able to produce. If you are operating a high-volume operation, you may consider opting for a machine with a larger nozzle. A typical dispense flow rate range is 0.2-0.5 oz/sec.

Features & Applications

Soda dispensers can be made available in several different configurations.  The first are the self-serve variety.  These are generally positioned in easy reach of a customer so they can dispense as much product as they require.  Some dispensers are coupled with built-in ice makers.  Other self-serve systems have bins that require ice to be transferred to the machine from an outside source.  The second variety are soda guns. These are operated exclusively by bartenders or servers in the restaurant. These are generally equipped with a push button design that allows the operator to quickly and easily switch between flavors.

Electrical Requirements

A typical beverage dispenser runs on a 115V / 60Hz / 3A power supply.

Temperature Range

The maximum acceptable temperature for dispensing a beverage is 40° Fahrenheit. The apparatus used to cool your liquid product may a cold plate or a more sophisticated evaporator coil, which forms an ice bank to ensure uniform temperature in your dispensed product.


Most beverage dispensers are designed using stainless steel. The soda nozzles or guns are made from durable plastics for their strength and longevity.  The tubing within these machines should also be considered. If you opt for a machine with plastic tubing, these tubes will need cleaning on a regular basis. Make sure you are aware of this before making your selection.

Tags: Bar, Tips, Beverage
Related Categories: Beverage Dispensing