Three laws of coffee roasting | interpretation of the baking principles of master roaster Scott Rao

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Scott Rao's The Coffee Roaster's Companion, published in 2014, can't help but burst into a cold sweat after a few years of re-reading it. He thinks he is a believer in his principle of baking beans, but in fact he makes a lot of mistakes in details, and he doesn't know it when there are hints in the book.

The following is the tenth chapter of this book, an excerpt of baked beans and my own thoughts.

1. At the beginning of baking, sufficient heat energy should be provided (the attached picture is intercepted from pdf)

As shown in the picture above, the temperature recovery point of An is higher and the flavor development of An is better than that of B.

My question: is the more firepower the better? does the increase in bean temperature have the same effect?

Now the firepower is getting bigger and bigger, so that when the explosion begins, there will be more room to adjust ROR to avoid flick.

Scott Rao's recent article The Soak changed his mind that the initial firepower should not be too large, avoid the drum temperature is too high, and can improve the development of coffee flavor and increase the room to avoid mistakes.

two。 The rate of temperature rise (ROR) must decrease.

If the ROR is increased, the sweetness will be sacrificed.

If the ROR is horizontal, the sweetness is destroyed and there is a plain, dry cereal, straw or carton flavor.

If ROR drops sharply, the flavor will not develop completely. Unless the beans are dropped immediately, the baked will be produced. If the ROR is 0 or negative, the sweetness will disappear completely, and the baking flavor will dominate the whole flavor.

The reason why temperature loss reduces sweetness and produces baking flavor is due to the developing sugar chain (sugar chains) cross-linking (cross-link) relationship.

The bean baker predicts and adjusts the heat according to the following conditions

If ROR starts to level out 1-2 minutes before the explosion.

During the explosion, the ROR drops sharply due to the cooling of the evaporated water vapor.

After the second explosion or later, ROR will accelerate up again.

My experience: the last three situations are the problems of crash & flick. They just forget what is mentioned in the books for a long time, but get used to it and think that it doesn't have that much impact. It was not until the curve was slightly adjusted last time that the flavor was found to have improved.

3. The first explosion should occur in the range of 75%-80% of the total baking time (development time accounts for 20-25%).

Definition of a burst: when an individual burst sound is heard more than twice.

This ratio is related to the degree of baking, and the best ratio is even in a narrower range.

If it is too much or less, it will produce the smell of baking, or lack of development.

Instead of talking about development time (development time), discuss the proportion of development time DTR (development time ratio).

Large bean dryer (above 10kg) is not subject to this limit, DTR only needs 15%.

This ratio is suitable for the baking degree before the first explosion and the second explosion.

My experience: at present, this part can not be mastered very well, mainly because there is always an obstacle that seems to be calculating mathematics with a set of formulas; for example, DTR is less than 20%, but it is time to get used to playing beans in the past, which is the most tangled at this time.

Later, after using Artisan software, the computer calculates DTR directly, eliminates psychological obstacles, and then overcomes the problem of crash & flick.