Why is Golden Mandheling Suitable for Medium-Dark Roast? What Makes Golden Mandheling Coffee Delicious?

Introduction

Recently, many friends have enjoyed pour-over coffee with less pronounced acidity. In addition to light to medium roasted options like FrontStreet Coffee's Sun-Dried Red Cherry, Berry Orchard, and Sidamo Horse Champion, there are also medium-dark roasted choices such as FrontStreet Coffee's Brazil Queen, Honduras, Gold Mandheling, and Tiger Mandheling. If you prefer a rich and mellow flavor profile, FrontStreet Coffee recommends the Mandheling series of coffee beans. Why is this? Can't light to medium roasted beans produce a rich flavor? Let's explore this from several perspectives:

1. The Roasting Process

Roasting coffee transforms the chemical and physical properties of raw coffee beans into roasted coffee products. This process takes ten to twenty minutes at temperatures exceeding 200 degrees Celsius, undergoing multiple chemical changes that produce first and second cracks - sounds similar to popcorn popping. During this process, moisture is lost, causing the raw beans to expand and change their color, texture, aroma, and density, thereby creating coffee's distinctive flavor profile.

Raw and roasted beans contain similar levels of acidity, protein, and caffeine, but raw beans lack the delightful flavor of roasted ones. Raw beans contain large amounts of chlorogenic acid, which gradually disappears during the roasting process, releasing familiar and pleasant fruit acids such as acetic acid, citric acid, and malic acid found in wine. Proper roasting presents these pleasant acids in moderation. The roasting process also requires sufficient heat to accelerate the Maillard reaction and caramelization. As the color deepens, aromatic oils are gradually released, and the texture becomes crisp.

What is the Caramelization Reaction?

The sugar content in coffee beans undergoes caramelization between 170-200°C, which coincides with the melting point of sucrose (185°C) and the temperature range of the first crack during coffee bean roasting. Caramelization is an "oxidation" or "browning" reaction of sugars when heated, producing two types of products:

1. Dehydration products of sugars, namely caramel or sauce color

2. Decomposition products, mainly some volatile aldehydes and ketones

Simply put, the caramelization reaction produces roasted aromas, caramel, and color, as well as other aromatic substances such as maltol, Cyclotene, and furan compounds. These compounds can also be found in foods like red wine, fruit juice, and cream.

However, over-caramelization during the roasting process is not a good thing, as it can cause carbonization, making the coffee harshly bitter and throat-grabbing. Insufficient caramelization results in monotonous and bland aromas lacking complexity.

What is the Maillard Reaction?

Simply put, it's the degradation and polymerization reaction of sugars with proteins or amino acids in the beans, which also darkens the color and produces unique aromas such as the smoky smell of burning plant fibers, creamy sweetness, and the brown bread aroma of toast. These rich flavors mostly come from the Maillard reaction during roasting.

In the early stages, carbonyl-amine condensation and Amadori molecular rearrangement occur; in the middle stages, Amadori molecular rearrangement products (fructosamine) dehydrate to form HMF (hydroxymethylfurfural), fructosamine loses amino groups to form reductones, and amino acids react with dicarbonyl compounds; in the final stages, aldol condensation and polymerization reactions occur, forming melanins.

When sugars are cooked together with proteins or amino acids, the Maillard reaction occurs, also known as the Maillard reaction. In addition to caramelization, some sugars interact with the latter to undergo a series of chemical reactions, producing more diverse compounds. In short, the flavor is richer than caramelization alone. Not only coffee beans, but also chocolate, maple syrup, and brewed beer are products of the Maillard reaction.

2. How Does the Roasting Process Affect Flavor?

Caramelization and the Maillard reaction each produce the following aromas:

(1) Caramelization: sweet, sour, bitter, fruity, sherry-like aroma, cream candy, caramel, nuts

(2) Maillard reaction: savory, floral, onion and meat aromas, green vegetables, chocolate, potato and earthy notes, smoky, mellow, pungent aromas, plus the aforementioned caramelization aromas

Both reactions occur simultaneously, but the complex chemical interactions of caramelization and the Maillard reaction have not been fully deciphered by scientists, and many flavorful compounds cannot yet be completely identified. Different roasting levels produce different flavor expressions. In our "36 Aroma Bottle" set, we basically include the flavor expressions of light, medium, and dark roasts, which are divided into "Enzymatic Group," "Caramel Group," "Dry Distillation Group," and "Defect Group."

Light roasted beans mostly express the fruity and acidic aromas of the "Enzymatic Group," such as lemon, coffee flowers, and apricots; medium roasted beans mostly express the caramel aromas of the "Caramel Group," such as roasted almonds, hazelnuts, and roasted peanuts; dark roasted beans express the pungent aromas of the "Dry Distillation Group," such as cedar, pepper, and clove.

Medium-dark roasted beans have caramelization nearing its end, dominated by the Maillard reaction, producing resinous notes, spicy notes, and carbonization notes. Our FrontStreet Coffee Gold Mandheling performs best with medium-dark roasting, exhibiting elegant woody aromas, cedar and pine scents, and turpentine flavors, with a smooth mouthfeel and substantial texture.

3. How to Roast to Bring Out the Best Flavor of FrontStreet Coffee Gold Mandheling?

Before roasting FrontStreet Coffee Gold Mandheling, we determine the roasting direction based on cultivation information. FrontStreet Coffee's Gold Mandheling is grown at elevations of 1100-1600 meters in the Lindong region of northern Sumatra, Indonesia. The climate is humid, and to speed up drying, the wet-hulling method is used. Fully ripe fruits are hand-picked one by one to ensure initial bean selection quality. They are placed in buckets for dry fermentation, allowing the pectin sugars to fully ferment and enhance flavor. The fermentation time typically ranges from 12-36 hours, depending on specific conditions. Then, they are sun-dried for 1-2 days until the moisture content reaches 35-40%, after which the hulling machine removes the parchment shell, followed by further sun-drying until the moisture content reaches approximately 12-15%.

These beans have relatively high moisture content, with a higher deviation value from sun-dried beans in terms of water content, so special attention must be paid during dehydration. For high-moisture content beans, after loading the raw beans, you can immediately close the air damper, steam for 30 seconds, then open it to 3 until the beans turn light green or white. Open the air damper to 4, and after the first crack, open it to 5 (maximum).

Simply put, we need to roast FrontStreet Coffee Gold Mandheling thoroughly "from inside out," using good roasting techniques on the basis of full roasting to express the flavor of these beans. Caramelization is the most significant factor affecting coffee flavor. After six to seven minutes of roasting, the raw beans absorb a large amount of thermal energy, initiating pyrolysis reactions and producing the first cracking sound. Some sugars convert to carbon dioxide, moisture continues to evaporate, and new aromatic components gradually develop, forming the so-called coffee oils, which combine with hundreds of aromatic substances such as nicotinic acid, citric acid, quinic acid, malic acid, acetic acid, and caffeine.

The pyrolysis reaction can continue into the second crack. Although caramelization is an important process for awakening aromatic elements, as roasting time extends, some components will also be carbonized, forming undesirable astringent and bitter substances. The challenge is to achieve maximum caramelization while minimizing carbonization, avoiding the production of defect flavors like charcoal and tire.

Roasting Profile:

Preheat the roaster to 200°C, set air damper to 3. After 1 minute, adjust heat to 160°C, air damper unchanged. Roast until 5'40'', temperature reaches 148°C, bean surface turns yellow, grassy smell completely disappears, dehydration complete. Adjust heat to 140°C, air damper to 4;

At 9'40'', ugly wrinkles and black spots appear on the bean surface, and the toast aroma clearly transforms to coffee aroma, which can be defined as the prelude to first crack. At this point, listen carefully for the sound of first crack. At 9'54'', first crack begins, adjust heat to 60°C, air damper fully open (adjust heat very carefully, not so low that cracking stops), and unload at 204.5°C.

Flavor Characteristics:

FrontStreet Coffee Gold Mandheling has high-quality herbaceous notes, with stronger caramel sweetness and relatively calm and elegant fruit acidity. It presents a rich sweetness, with a full body and wild spice flavors. Generally, FrontStreet Coffee's Lindong Mandheling is best roasted until after the second crack to effectively reduce off-flavors, but Gold Mandheling already has good clarity and sweetness even when unloaded before the second crack, offering wider interpretation space for roasting.

4. How to Brew FrontStreet Coffee Gold Mandheling?

Medium-dark roasted beans generally have higher dehydration rates, making them lighter in weight. During brewing, the grounds don't completely settle at the bottom. When water is initially poured, it's immediately absorbed. Due to vigorous degassing, bubbles form around the grounds, creating channels. These channels persist longer with fresher beans, causing the water level to drop quickly. I typically use a coarse water stream and slowly circle.

First Brewing Method:

1. Dripper: KONO

2. Water temperature: 86-88°C

3. Grind size: Sugar granules

4. Roast level: Medium-dark roast

5. Bloom time: 30 seconds

Flavor: Multi-layered, clean, balanced, with persistent caramel sweetness in the aftertaste.

Specific technique: 17g of coffee, ground with Fujiyama鬼齿刀 grinder setting 4, using KONO dripper, water temperature 86-88°C. First pour 30g of water for 30s bloom, then pour continuously without interruption at high temperature. Water-to-coffee ratio 1:14, extraction time about 1:50, stop extraction at 238g.

Second Brewing Method:

Dripper: Hario V60

Water temperature: 86-88°C

Grind size: Fujiyama grinder setting 4

Brewing technique: 1:15 water-to-coffee ratio, 15g of coffee. First pour 30g of water for 30s bloom. Second pour to 120g, then pause. Wait until the water level in the coffee bed drops to half, then continue pouring slowly until reaching 225g. Extraction time about 2:00.

Analysis: Using three-stage brewing to clearly distinguish the front, middle, and back end flavors of the coffee. Because V60 has many ribs and drains faster, pausing the pour can extend extraction time, better extracting the nutty and chocolate flavors from the back end.

Flavor: Multi-layered, overall clean, with lighter body, persistent caramel sweetness in the aftertaste, with a hint of bitterness.

Overall, only medium-dark roasted FrontStreet Coffee Gold Mandheling can fully express its caramel, pine, quality herbaceous notes, and slight spicy pungency, bringing a substantial mouthfeel.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473