More science goes into making a good cup of coffee than just about any other restaurant preparation process. The perfect coffee — even just a good cup of coffee — is the combination of at least six different brewing variables that are discussed below. If you can master these variables and use the right equipment, you'll win customers over every time.
Not long ago coffee brewing simply involved spraying hot water over ground beans for a set amount of time. The coffee was merely drip brewed with unsophisticated equipment and held in simple urns at a set temperature. Current machines are more sophisticated and allow operators to achieve their desired taste profile with precise temperatures and a variety of brew times and product volumes. The latest coffee equipment applies more science to the art of coffee making. Here are the main types of coffee equipment that may fit your operation.
Single-pot brewers
For a small-volume outlet, the basic single-pot brewer may be the product of choice. These units drip hot water through coffee into decanters that sit on a warming plate. The models can be the pour-over type, meaning water is manually poured into a reservoir to make coffee with no water connection needed. But pot brewers can also be plumbed for automatic water filling. There is some variation in sizes but most of these models usually brew about a half-gallon in about four minutes. Even in these simple machines a water temperature of 200°F and holding temperature of 185°F are critical to product quality.
Airpot brewers
The next coffee-maker type has surged in popularity because of its flexibility in serving the coffee once it is made. The unit is the airpot brewer. Coffee is actually made the same way as a pot brewer except the coffee is brewed directly into containers called airpots that are completely sealed and insulated. They can hold coffee temperature and quality for several hours compared to the pot brewer hold time of about 20 minutes. Airpots are attractive and easy for customers to operate. They are excellent for serving a variety of specialty or flavored coffees, since a group of airpots can be held on a rack for merchandising. These portable containers are usually one to three liters in capacity. Serving from an airpot is sanitary since the coffee is never open to contamination. Airpots are easy for customers pouring their own coffee in a buffet or quick-service application.
Urns
The move up in coffee volume from one of these brewers is to an urn, most likely a double three-gallon model used in many medium to large restaurants. A few manufacturers make smaller urns, but the most popular is the twin three-gallon unit. As a rule of thumb, consider using an urn when serving six gallons of coffee, roughly 100 eight-ounce coffee cups or more in one hour. The twin three-gallon urn can make up to about 600 cups of coffee in an hour.
A common purchasing mistake is to buy too large a coffee maker. If your operation needs to deal effectively with decaf coffee or any other special blends or flavored coffees you need to consider having multiple urns or some portable thermal dispensers to accommodate the different brews. Most urns made today have some quality brewing features built in.
A basic feature is a water bypass, which diverts water around the coffee being brewed directly into the urn to prevent over extraction of the grounds. Another feature you'll want is automatic agitation. Coffee strength varies during the brewing cycle and agitation is needed to mix the coffee to uniform consistency. If you don't have an agitation feature, just draw off some coffee once brewing is complete and pour it back into the urn to mix the stratified flavor strengths.
Modular brewers
The next machine type is the modular brewer. This type of unit is used in high-volume operations. It consists of a fixed brewing module that controls the temperature and volume of water used. There are usually spaces for two brewing containers that can be attached to a hose or spout of the brewing module. The brewing containers vary in size with some up to 20 liters and some may have their own heaters. The modular brewer offers flexibility and is a versatile option for an operation needing a lot of coffee in several locations or for large volume banquets.
A new type of brewer is making its way into specialty stores to respond to the market for premium specialty coffees. The idea behind the machines is that different coffees with different countries of origin have different grinds, brew temperatures and times to bring out the best flavors of the beans. The units feature computerized brew settings to deliver on the promise of distinctive taste, though they are typically used by baristas familiar with the various coffees being served.
Elements of Coffee Brewing
Here are the six different variables that will lead to brewing perfection:
- Water
Since water makes up about 98 percent of a cup of coffee, it's only logical that good water will go a long way to making a great coffee. A good water filter is a must. Ideally water should be free of any odors or off tastes and dissolved minerals should be about 50-100 parts per million.
- Time
The time water is in contact with ground coffee determines how well and how much coffee is extracted. The ideal balance of coffee strength is the amount of coffee used and the time it's in contact with water. You want to optimize this balance for the best coffee.
- Temperature
The perfect water temperature during brewing is about 200°F, but may vary between 195° and 205°F, depending on the grind and coffee type.
- Turbulence
As hot water passes over the ground coffee, turbulence is created, which determines how soluble material is released into the mix.
- Filtration
Filters must be porous enough to allow extracted coffee solubles to flow through while not allowing solids to pass through. A quality paper filter is a must.
- Cleanliness
Keep your coffee equipment clean. Use a good cleanser made for coffee equipment daily. Specially made cleansers will ensure that undesirable tastes are not transferred and hard water deposits will be removed.
If you want to make your operation known for a great cup of coffee, choose the right equipment and follow the elements of better brewing noted above.
Dan Bendall is a principal of FoodStrategy, a Maryland-based consulting firm specializing in planning foodservice facilities. He can be reached at dbendall@foodstrategy.com.
