Quality control in a roastery: What does it mean & why is it essential?

Esther Gibbs
November 24, 2022

The ability to consistently produce a quality cup of coffee that is full of flavour and aroma is essential for coffee roasters.

Consistency is key for businesses to keep customers happy and to ensure success and growth. That said, achieving consistency can be challenging, as roasting coffee is a complex process that is affected by many variables, such as charge temperature and the characteristics of the green coffee.

A slight shift in one of these variables can lead to a wide range of taste spectrum. If a customer has a different experience with each order, it is unlikely they continue to invest their money in the brand. Customers tend to be more loyal to an experience they can trust.

One way you can maintain consistency is through quality control. In essence, quality control is defined as a system of maintaining standards in manufactured products by testing a sample of the output against the specification.

Taking time to check products are consistent and reaching high standards can help ensure customers have the same experience every time and will make repeat purchases.

In the first part of our Quality Control series, we explore some standard quality control measures before we dive into different forms of the practice often used in coffee roasteries. 

An image of a roaster conducting a cupping session in order to determine quality of roast coffee in an article about quality control in roasteries

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Do roasters need to do quality control?

Quality checks should begin with green coffee, to ensure it is not deteriorating with age or due to the environment in which it is stored.

This includes measuring and recording the environmental temperature and humidity within the roastery. This can help you ensure green coffee is stored in optimum conditions. 

It is also essential you measure and record the moisture and density of green coffee to ensure it is within the contractual agreement and of good quality. 

This is to make sure the coffee will roast the way you expect, as the moisture and density should be the same as when the coffee was profiled. 

Furthermore, it is important you follow the designated roast profile consistently each time you roast. The smallest change in temperature, between batch protocol, airflow, drum speed, or rate of rise, may leave a different result in the cup.   

While these minimal adjustments may not make the quality of the cup unpleasant, they may affect the solubility of the coffee. 

In turn, this may mean customers will have to adjust their grinder for each batch of coffee they use. This can create frustration or tension in the relationship between you and your customers. Additionally, it may also mean consumers are serving your product at a lower standard.

It is also important to have a tracking system that traces the coffee from customers back to the roast batch on your software. Then, if there is a complaint, you will be able to analyse where it went wrong and recall products if needed. 

Once your roast profile has been perfected, it can be saved, making it easier to repeat. It is advisable to save each roast graph individually with a batch number, date, and the coffee used. 

This information should be saved in a folder each day to track every coffee in case of a complaint. Then, if a roast profile does not match, you can taste it and perform further quality control on the beans before making a decision.

An image of a coffee farmer measuring the density of green coffee as part of quality control procedures in an article about quality control in roasteries

Ways in which roasters conduct quality control 

Cupping and tasting your coffee in a standardised way can ensure it is being roasted to the same flavour profile you initially intended. 

You can choose to follow the Specialty Coffee Association cupping standard and use their scoring sheets, or you can create your own with the attributes and qualities you are looking for.

Then, if a cup has an unexpected taste, you can revisit the profile to see what you did differently and adjust accordingly to remain consistent.  

Weight loss, density & moisture in roast coffee

Measuring the weight loss, moisture content, and density changes after each roast can ensure it has been roasted to a similar level. 

Most of the weight loss in a roast is due to the moisture that escapes the beans, and lighter roasts tend to lose less moisture compared to darker profiles. 

By maintaining these factors, you are able to ensure the solubility of the coffee is consistent and it will extract the same way with every brew.  

More so, keeping records of the weight loss, moisture content, and density changes of each roast can be useful for tracking green inventory. 

Additionally, you may find it beneficial financially, as essentially, weight loss in coffee often results in lost profits. Therefore, you will be able to track how much you are making per kilogram of coffee accurately. 

Measuring Total Dissolved Solid (TDS)

During a cupping session, it is advisable to use a Total Dissolved Solids (TDS) reading from a refractometer in order to get a better understanding of the extraction level of the coffee. 

A TDS reading indicates the concentration of coffee solubles in a cup of coffee. This can help ensure your roast coffee reaches the same extraction levels so consumers will be able to brew it consistently at home. 

Using a colour meter

A colour meter provides a measurement of the roast degree for your beans. Checking the colour of the roast and ground coffee can ensure a roast is within your tolerance range. 

If the roast lies outside of this, you will be able to perform further sensory analysis before deciding whether to ship the coffee to the customer. 

An image of a coffee roaster smelling a sample of fresh roast coffee as part of quality control procedures in an article about quality control in roasteries

Final considerations for quality control in your roastery

“In and out tests” are a quick-fire way to see if coffee is up to standard when analytical tests fall outside of tolerances.

For this test, you will need a reference cup of the coffee that matches the profile. Then, you will line up the coffees in a random order. To ensure you know which coffee is which, it is advised to place stickers on the bottom of each cup. 

Taste each one and compare it to the reference cup. If the coffee tastes similar enough to the profile, send it to the customer. If not, find another creative solution to use that coffee.

Alternatively, you can choose to triangulate coffees where analytical tests fall outside of tolerances.

To do this, prepare three cups of coffee. Two will be coffee A, or your reference, while one will be coffee B: the one that falls out of the tolerance.

Taste and see if you can identify the odd one out, but be sure to reference coffee B with a sticker. If you can consistently taste the odd one out across multiple tests, do not send it to your customers. 

If you are unable to find the odd one out, then the coffee tastes similar enough and you can send it out.

It may also be incredibly beneficial to offer your wholesale customers’ barista training. This will ensure they are serving your coffee to a standard that upholds your brand. 

The last point of quality control will be your packaging. The packaging materials should be of the highest quality to ensure your coffee is kept fresh and retains flavour. 

Many roasters offer both compostable and recyclable coffee bag options with an airtight seal and a degassing valve.

At MTPak Coffee, our range of sustainable coffee packaging options is made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging that comes with an environmentally friendly PLA lining

Our sustainable degassing valves allow carbon dioxide (CO2) to be released without letting any oxygen back into the bag, giving customers the best expression of roast coffee. 

More so, we give our clients complete control over the design process by allowing you to build your own coffee bags. Our design team is available to help create the ideal look for any type of coffee packaging. Plus, we offer a quick turnaround time of 40-hours and 24-hour shipping time. 

For more information on custom-print sustainable coffee packaging, contact our team. 

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