Why do you raise roasted coffee? How long does it take to keep coffee beans?

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There are different opinions in the industry on how long the coffee should be left after roasting, and there is some controversy even within our company.

In order to find the best solution, we have conducted an in-depth study of this problem. Let's start with the conclusion and gradually solve the mystery of the problem: how long should the coffee be kept before drinking?

Our conclusion is:-coffee in standard packaging (no gas filling) should be left 1-3 weeks after baking before drinking (1.5 weeks is the best);-coffee packed with gas should be left 2 weeks after baking.

How did we come to this conclusion?

First of all, we have to make it clear: why is coffee "raised" after roasting?

"raising" refers to the process in which the taste of coffee changes over a period of time, especially a positive change.

"raise" is different from spoilage, which refers to the process in which the taste of coffee gradually deteriorates.

Whether it is "raised" or deteriorated, the taste of coffee does change greatly during a period of time after roasting.

The change in taste is mainly due to:-the migration of chemical components refers to the diffusion of chemicals inside the coffee into the surrounding environment, mainly due to the evaporation of carbon dioxide, volatile substances, water or water vapor, etc. diffusion will take away the original flavor substances, oils and other solid / liquid substances inside the coffee. Similarly, external chemical components will also be introduced into the coffee because of the flow of carbon dioxide, volatile substances, water, air, etc., as shown below:-changes in chemical composition means that chemical substances react, including liquid, gaseous and solid reactions, including oxidation, reduction, polymerization and hydrolysis. These reactions change the chemicals in the coffee, thereby changing the aroma and taste of the coffee.

The above two processes are very complex, and you must also take into account the origin of the coffee, the degree of roasting, water activity (before and after roasting) and environmental factors.

It was difficult to take all the factors into account, but we decided to face up to the difficulties.

Of course, we have simplified the process of the experiment, and our goal is very simple, that is to detect how long the coffee should be left to drink after roasting!

How do we do it?

We qualitatively and quantitatively analyzed three kinds of coffee: light roasting, moderate roasting and deep roasting. All coffee is baked at the same time and in the same environment. We found that there was a big difference in the performance between the coffee packed with gas (nitrogen) and the coffee without gas filling. We tested the taste of coffee one week, two weeks, four weeks and eight weeks after roasting.

-five people were involved in the experiment, including a Q Grader certifier;-We took into account individual taste differences and recorded the results of each test;-We rated coffee in terms of sweetness, taste, milk base and balance, with a total score of 5;-We classified and summarized the tastes we perceived. -We do not control the room temperature environment, but we can determine that the temperature is between 18 °and 26 °;-We do not control the humidity, indoor air pressure and other factors during baking.

Before reaching a conclusion, we must first understand that the results of scientific research are not absolute and that the figures only provide us with a standard for reference.

In this study, at first we didn't know which roasted coffee should be used as a reference (but in the end we got the answer! ), so our results only show the difference between inflatable and uninflated packaged coffee.

We know that even inflatable packaging is not fully insured, and chemical migration and reactions still occur in coffee, but the final results show that when the preservation date reaches a certain length, the performance of inflatable packaged coffee is indeed better than that of uninflatable packaged coffee.

What's our conclusion?

As we said at the beginning, we found that the best drinking time for uninflatable coffee is within 3 weeks after roasting (preferably 1.5 weeks), and the best drinking time for inflatable coffee is 2 weeks after roasting.

After baking for 1 week, we found that the uninflated coffee was rich in taste, balanced in taste (preserved at 21 °room temperature), and milk-based coffee performed well.

We found that inflatable packaged coffee had a sharp taste within 2 weeks after roasting, but the performance of milk-based coffee was better than that of uninflated coffee.

In Australia, more than 85% of coffee is consumed in the form of milk-based coffee, so the results may have implications for coffee shop operators.

After four weeks of baking, inflatable packaged coffee began to taste softer, richer, more balanced, and milk-based coffee performed well.

In contrast, the taste complexity of uninflatable packaged coffee decreased significantly 4 weeks after roasting, and the performance of milk-based coffee was poor.

Although it can still be tasted separately, we do not recommend drinking uninflatable coffee alone for more than 4 weeks, as does milk-based coffee.

After eight weeks of roasting, inflatable packaged coffee still tastes delicious, while uninflatable packaged coffee is reduced by at least 50%.

After the experiment at this stage, we can confirm that the shelf life of uninflatable packaged coffee is 3 weeks. If more than three weeks, the coffee will begin to change. For coffee shop operators, we recommend that roasted coffee should be used up within 1-2 weeks, including light, medium and deep roasted coffee.

If it is inflatable, the coffee can be kept fresh for 8 weeks, during which time the taste of the coffee will not be reduced, but will be slightly enhanced.

There is no problem with milk-based coffee for 8 weeks. If you taste it alone, we recommend drinking it within 2 weeks after baking.