A good roaster should be able to master the variables within a machine to manipulate the transferral of heat in a coffee bean, producing the most desirable flavours in a cup.
Once this preferred cup is determined, it is recorded on software or by hand as a repeatable “recipe” called a roast profile.
These are essential for quality control as the smallest change in a variable on the machine can lead to a completely different flavour in the cup of coffee. Notably, with espresso roasts, it can mean customers may need to alter variables on their machines to achieve a balanced beverage.
These variables may include charge temperature, end temperature, airflow, rate of rise, drum speed, and roast duration.
The problem is that profiling a coffee when it first arrives is a long process. Furthermore, it can take endless amounts of roasts with small or large adjustments to find that perfect cup.
Read on to learn how you can upscale your sample roast for production.
What is the problem coffee roasters face?
When you have a large roaster or extremely high-quality coffee, profiling can become an expensive process.
As a result, some roasters may buy a smaller sample roasting machine to test on. Alternatively, others may choose to use the smallest batch size available on their current roaster.
However, production roasting in smaller batches is often the less feasible option, as it can take up significant time. If it takes 6 minutes to sample roast 250g (8oz), how can you upscale it to get the same result as a 5kg (176oz) roast?
Increasing the volume of your sample roast
There are two possible scenarios to cover here. One allows for a small increase in coffee, while the other allows for a larger increase.
Scenario 1: Small increases
For this adjustment on a small-capacity roaster, it is possible to match the profile almost perfectly by following a few tips.
First, when profiling a smaller volume, it is important you refrain from using the maximum capacity of any variables. This ensures you have room to increase it for larger roasts.
If it is less than 50% of the roasting machine’s total weight capacity, avoid going above 60% on power and keep the charge temperature low.
Second, match the roast profiles by matching the turning point at the bottom of the profile. Once this is done, it is possible to hit all the other points on the roaster accordingly by increasing the amount of power used from the smaller roast.
To hit the turning point, ensure the roaster is pre-heated properly. This can help you avoid losing any energy, charge higher than the 2kg (70oz) roast, and start with your gas on a higher setting.
Last, follow the rate of rise (RoR) on the original profile and match it to give you the same time for first crack and the end temperature to drop.
Scenario B: Larger increases
In this scenario, you are aiming to match the original roast profile proportionally instead of matching the time within the roast.
Most coffee roasting software should offer you the opportunity to mark yellow or colour changes, which signals the end of the drying phase. It should also allow you to mark the first crack, signalling the start of the development phase, and the end of roast.
These are often then displayed with a percentage of the roast time:
- Middle, also known as the Maillard reaction. However, it is important to note that the Maillard reaction rarely ‘ends’ at first crack.
When scaling up a roast, it is preferable to match these percentages with your larger roast.
For example, 50% drying time, 30% middle and 20% end.
For the first roast, it is advisable to note down some key temperatures and times you want to hit. For instance, a turning point at 3 minutes, a colour change by 7 minutes, first crack by 11 minutes, and end of roast temperature by 14 minutes.
Colour change, first crack, and end temperature should be numbers you are familiar with while working on your roaster. It is then possible to calculate how high the rate of rise (RoR) should be during each phase of the roast.
Then, while you are roasting the first profile, you can adjust the gas accordingly.
This provides a base profile to work from. While it may not be perfect the first time, it can help you make improvements on each roast moving forward.
How to check your roast profile matches
It is important to use the physical measurements of the coffee to ensure you are roasting it correctly.
If the beans have the same physical properties after roasting, then it should provide the same result, even during extraction.
Factors to consider are:
- The percentage of weight loss in the coffee. Be sure to measure the difference in weight loss before and after roasting, as you are aiming to have the same percentage. Notably, the majority of the weight lost is moisture content.
- Colour check: It is advisable to invest in a colour meter that measures the ground coffee and the whole beans to ensure they are within a tolerance of your sample roast. If the ground coffee is lighter or darker, you may need to extend the middle phase of the roast to ensure better development. If the whole beans differ in colour, consider the drum speed or development time after first crack.
- Moisture and density: If the moisture content of your larger roast is higher, you may have to increase the airflow or total roast time. However, if it is lower, it is advised that you reduce both.
Additionally, it is advised that you create a simple cupping form and properties table that suits your business.
These can help you profile and upscale your roasts by keeping a record of everything, helping you match the key characteristics you want in the cup.
More so, cup every roast and make notes referring back to changes you made in the profile. This can help you continue to learn and develop your palate and skills as a roaster and make it easier the next time.
After all that hard work, it is essential your coffee remains fresh for customers. Investing in high-quality, sustainable coffee packaging can help you maintain your reputation for a premium, freshly roasted product.
MTPak Coffee offers a selection of 100% recyclable coffee packaging options ranging from coffee bags made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining, as well as custom coffee mailer boxes made from 100% recycled cardboard.
This allows us to offer low minimum order quantity (MOQ) with a quick turnaround time of 40-hours and 24-hour shipping time.