Starting up a roasting coffee plant

One certainty: to start a roasting coffee plant, you need to have a great business sense, a vision that you absolutely believe in, the strength to stick with it until you succeed and a passion for this wonderful product.

The preliminary questions a business plan should usually responds to and that are clear from the beginning, are:

THE MARKET

Are you serving or planning to serve retail customers, distributors, grocery store customers, e-commerce etc?

THE FINAL PRODUCT

What type of final product would you like to sell?

Whole beans, ground coffee or both? What is the ratio between the beans and ground coffee? 100% whole beans, 50% and 50% or 100% ground.

If ground, what type of particle size?

Filter, Espresso, Turkish or Moka, Single serve?

THE FINAL PACKAGING

What kind of final packaging will you be using?

Normal or vacuum packs, cans, soft or hard pods, auto-protected capsules or with flow pack?

The choice of the final packaging involves a lot of considerations which we have to bear in mind in order to properly evaluate each and every step required beforehand.

Answering these questions requires a major effort. After that, you only have to identify the supplier that can meet your needs.

What about technical utilities required for installation?

Before making a technical evaluation of the project, it’s extremely important to be clear on what requirements are needed. The facility should have adequate gas, electricity and compressed air; plumbing, ceiling and most importantly enough space and height to contain all the equipment.

Now we can start to evaluate the roasting project and the plant equipment you will need.

Starting with the core of a roasting coffee plant, we need to answer one main question.

How many kg or tons of coffee do you expect to produce daily, weekly or yearly?

This answer can first help to identify the most suitable roaster size for your needs, but also the other complementary equipment for the roasting project. These considerations depend also on the planned working load and shifts per day. By this estimation, we can easily identify what capacity the roaster should have.

There are many types and sizes of drum roasters.

Starting from the Specialty Roasters that can roast up to 60-80kg per hour, suitable for small business, coffee shops or pilot plant machines. The traditional drum roaster with a 70/30% convection/conduction ratio suitable for gourmet coffee with a roasting time ranging from 12 to 20 minutes. Its capacity can vary from 200kg up to 1,600kg/h.

A modular drum roaster with a 90/10% convection/conduction ratio suitable for a wide range of coffee roasting profiles, and with a roasting time ranging from 8 to 20 minutes. Its capacity can vary from 1,000kg up to 3,600 kg/h.

In addition to capacity needs and the type of roasting technologies applied, the selection must be carried out by taking in account the level of automation of the coffee roasting process.

How do you want to control the roasting process?

Depending on the size and the level of automation desired, roasting control can be manual, semi-automatic with inlet temperature control, or fully-automatic with pre-drawn profile control. This choice has a definite impact on the consistency and reproducibility of the taste of the final product.

ADDITIONAL ROASTER EQUIPMENT

Green coffee loader

If the roasting capacity is not too big or if green coffee storage is not required or cannot is off budget, we can load the machine with a pneumatic elevator. This consists of a hopper where the operator loads the already weighed green coffee and which automatically lifts it up to the roaster.

Destoner

A destoner is one piece of equipment we need to consider in the roaster application. It removes foreign bodies with a specific weight heavier than the roasted coffee. Nowadays, coffees are increasingly dirty and, as you probably know, stones or metal can damage your grinder.

Afterburner and catalyser

Roasted emissions into atmosphere are becoming more and more strictly regulated worldwide. So, especially on an industrial scale, roasting emissions have to be dealt with. In order to do so, the roasters could be equipped with a thermal afterburner and/or a catalyser, depending on the roaster size and the limits required by the town and the State.

It is critical to identify and evaluate where the equipment will be installed so you can assist us in finding out what emissions limits must be observed.

Now that the roasting project has been defined, we can start to design the other complementary equipment for the roasting plant. Most of the time, green coffee storage is useful and recommended for a plant with a 500kg/h capacity.

The most suitable green coffee storage solution should consider:

1. how many coffee origins you will use during production;
2. the desired storage time in green silos or in the warehouse
3. but the above always depend on the availability of space

STORAGE SILOS

Suitable storage time varies from a minimum of 3 days up to 1 month. The bigger the storage space, the better, especially when we have multiple coffee origins, because it is useful for blending the batch and sending it automatically  to the coffee roaster.

The number of the silo cells depends on the number of coffee origins we have. The storage solution could be indoors or outdoors, depending on the facility space available, and in different shapes: squared, polygonal or circular. Even the shape may depend on the plant layout. To summarise, squared silos are recommended as large storage solutions; circular silos need more space due to their characteristic shape, but they are the best solution in terms of hygiene since they have no corners where dust can collect. The best solution for medium size plants is the polygonal silo, which can offer a higher capacity in less space.

To give one example, 1 polygonal silo with 6-8 cells could contain up to 20T of green coffee, in a space measuring 3.5 meters in diameter by 9-10 meters height.

WEIGHING SYSTEMS

Beneath the silos, we need to install a batch weighing system in order to prepare the green coffee blend, or to weigh single origin coffee to be sent to the roaster. The capacity of the batch weighing system should be the same or bigger than the roaster capacity, and the weight will be recorded and used for calculate the roasting yield.

The easy and flexible way to convey the green coffee from the weighing system to the roaster is using a pneumatic conveyor, since green coffee is not subject to breakage.

After the roasting process, we have to consider the importance of preserving the integrity of the whole roasted coffee beans, much more prone to breakage than the green bean, by installing proper conveying and handling equipment. The important question to answer is: how do you plan to handle the coffee once roasted?

If the roasting output is not high, you can store your coffee in plastic or even better in stainless steel trays, but I recommend covering it. Otherwise, silo capacity can vary from a few hundred kg up to many tons and the shape, as for green coffee, depends on the capacity and available space.

The numbers of cells strictly depends on the different type of coffee you will produce, (single origin or blended) and on the maturation time desired. Every roasted coffee silo compartment must be equipped with “fall shock absorber” namely a device to gentle handle the coffee during its descent so as not to hit the bottom and break. If we want to roast by single origin, blending after roasting, a mixer is required. This equipment has the same concept of a roasting drum with a paddle system inside to mix the coffee evenly. Roasted coffee can be handled pneumatically or mechanically, which is better depending on the capacity/h and the distance from the connected equipment. A bucket or disc type mechanical conveyor is more suitable for short distance since both are very gentle but the second one is cleaner and more flexible. A dense or dilute phase type pneumatic conveyor is more suitable for long distance and for linking up more than one piece of equipment, and can be easily modified in the case of plant expansion. Considering the long distance and the need to avoid breakages, this type of conveyor should be equipped with a speed control that changes velocity according to the specific weight of the coffee. 

If your business deals only in the distribution of whole beans, the job is almost done. However if you need to produce ground coffee in the various types of packaging , we have to take other aspects into consideration. We will have one episode dedicated to grinding, where we will talk about all the necessary considerations involved in choosing the right grinder and degassing system for your project. There are only two certainties: consistency particle size and cool output will be the priority for any type of coffee we need, especially when we are going to have certain types of coffee packaging.

The ground coffee silos are needed if required by the type of final packaging, like vacuum pack or auto protected capsules, and in this case we have to maintain the aromas developed during roasting as high as possible, preserving the coffee from oxidation and going stale, which will definitely affect the coffee as soon as it’s ground. At this point in particular we must take care of our coffee, protecting it with nitrogen flush. Degassing time could range from 4 to 48 hours depending on roasting colour degree, roasting time, ground coffee particle size, ambient temperature etc, but again we will tell you more about these topics in another episode

In the next episode we will look in detail at the important things to know about green coffee with an overview of the equipment needed to receive and treat it.