Draft System 101: How a draft system functions

In this Draft System 101 series, we will be exploring and breaking down the concepts of how the systems function. To put it in most basic terms, the purpose is intended to save costs, minimize waste, and make a simple way to serve all sort of beverages. A draft system, while primarily designed for dispensing beer, can be adapted to serve cocktails and cold brew coffee as well. Here’s a breakdown of the basic components and how they function for each type of beverage:

1. How a Draft System Works for Beer:

• Storage & Pressure: Beer is stored in a keg under pressure (usually CO2). The gas pushes the beer through the lines to the faucet. The pressure can be adjusted to ensure that the beer is dispensed at the correct carbonation level and flow rate.

• Serving: As you pull the tap, the pressurized gas forces the beer out of the keg, through the lines, and into your glass. The right pressure also helps maintain the beer’s carbonation.

2. How a Draft System Works for Cocktails:

• Storage: Cocktails are often pre-mixed and stored in kegs. This can include classics like Negronis, margaritas, or more complex recipes. The key is to ensure that the cocktail components are well-chilled and properly mixed.

• Gas Pressure: Like beer, a cocktail keg is pressurized (usually with nitrogen or CO2), but since cocktails are usually not carbonated (unless it’s a fizzy drink like a spritz), nitrogen might be used solely to push the liquid out of the keg and through the lines. A lower pressure may be used compared to beer to avoid over-carbonating any mixers.

• Serving: The bartender pulls the tap, and the cocktail is dispensed. Since cocktails are typically served over ice, some systems have a built-in option to chill the drink further or have a separate ice reservoir near the pour point. This allows for bars to more easily track how much they've served, and minimize any waste.

3. How a Draft System Works for Cold Brew Coffee:

• Storage: Cold brew coffee is typically pre-brewed and then stored in a keg. It's important that the cold brew is kept at a low temperature to preserve its flavor and prevent oxidation, as well to limit bacterial growth.

• Gas Pressure: The system uses nitrogen (almost never CO2) to push the cold brew out of the keg. The coffee can either be served still (with no head) or "nitro", which can be achieved by adjusting the pressure upwards. For nitro cold brew, very high pressure nitrogen is used to create a smooth, creamy texture and a frothy head.

• Serving: The cold brew is dispensed through the faucet directly into a glass, usually over ice. Nitro cold brew will have a smooth, velvety texture with a dense foam on top, whereas regular cold brew will pour more like traditional coffee.

Key Considerations for Different Beverages:

• Beer: Requires careful control of pressure to maintain the right carbonation. CO2 is used to both carbonate and push the beer.

• Cocktails: Often pre-mixed and may need to be kept chilled. The pressure is used only to dispense the drink, not for carbonation (unless it’s a fizzy cocktail).

• Cold Brew Coffee: Typically served still, but can be "nitrogenated" or "nitro" if desired. The nitrogen gas pressure is used for dispensing at a much higher pressure for "Nitro", and a lower pressure for cold brew.

  

Summary:

In a beer draft system, simply put, gas pressure (CO2 or nitrogen) is used to push a beverage from the keg to the faucet. The system is adjustable based on the beverage—beer requires proper carbonation and pressure, while cocktails and cold brew coffee may just require pressure for dispensing. For cold brew coffee, nitrogen is sometimes used for a smoother texture, similar to nitro beer. This versatility allows the system to serve a wide range of drinks with ease, minimizing waste, and maximizing freshness.