The Roaster’s Practical Guide to Coffee Blending

The Roaster’s Practical Guide to Coffee Blending

Coffee Blending is time-honored pairing of sensory arts and pragmatic concerns, and for many coffee drinkers remains one of the most recognizable ways to distinguish a coffee.  

This article will introduce roasters to basic blending concepts and attempt to answer some critical questions when creating coffee blends for various markets and applications. We’ll also look at a couple of common blend types and how you can create your own.

Blends or Single Origins?  

Blends stand in opposition to the other major category of coffee packaging and marketing: single origins.  

Single Origins are defined by the source of the green coffee, typically using the country as the common denominator.   

Blends are defined as a mix of multiple lots, usually created by a roaster after sourcing.  

Surprisingly, there are opportunities for overlap here, the most apparent of which is that coffees from multiple producers potentially separated by thousands of miles could be blended in a generic country profile and still qualify as a single origin to an exporter. Regional blends such as Colombia Medellin Supremo or Sumatra Mandheling are popular options for many countries where traceability may be negligible, and the small scale of most farmers presents logistical challenges to lot separation. Similarly, cooperatives typically blend the delivered harvest from their many members and separate them into day lots – a collection of coffee processed together in a single batch. Finally, it’s even possible to blend coffee from a single farm or estate – perhaps the farmer has chosen to combine the harvest of two adjacent parcels, or blend to similar day lots together. The possibilities go on, but the point is that many “Single Origins” are in truth blended coffees (often of similar provenance) going back as far upstream as the farm.  

When a roaster decides to create a blend, there are a few important angles to consider, including:  

  • Flavor  
  • Costs  
  • Applications / Usages  
  • Pre or Post-Roast Blending?  
  • Minimum Percentages? How many coffees? 
  • Common Blends  
  • Thoughts on Traceability  

Blending for Flavor  

Perhaps more than in a single origin, one of the usual attributes favored in blends is “balance” – the idea that the flavors should be working harmoniously together. Quite the opposite of “neutral,” balanced coffees may be dynamic and full of complex flavors, but critical elements such as sweetness, acidity, body, and finish should work to complement one another. 

There is perhaps no greater opportunity to achieve a balanced cup of coffee than by crafting a well-orchestrated blend. A common recipe might include placeholders for components such as “base,” “mid,” and “high” whose percentages and components can be adjusted to create a clean and interesting cup of coffee with a steady flavor profile allowing for easy replacements when supply runs thin.  

Seasonal blends offer the creative roaster a chance to capitalize on associated flavor profiles and offerings. Classic examples might include a holiday blend with notes of baking spices or a spring blend with hints of floral flavors. The possibilities here are vast, and one can easily imagine culinary themes emerging.  

Hiding flavor can also be achieved by blending, and while we’d shy away from endorsing opacity in labeling, most roasters know that at some point or another they’ll be in the uncomfortable position of possessing a sub-standard coffee. Using this coffee as a minority percentage in a blend, particularly when the other components have bold flavors (perhaps a big chocolatey Uganda, a massively herbal Sulawesi, a zestfully citric Kenya, a fruit-bomb natural, or simply a darker roast) can help to mask its flaws and create an opportunity to move inventory.  

Blending for Finance  

The cost of goods is a critical concern for many applications to a roaster. One of my favorite examples of this can be coffee destined for grocery shelves, where the roaster’s margin is often razor-thin in order to hit a target price for the vendor.  

Not only do blends for grocery shelves often achieve the goal of targeting a demographic more likely to choose them than a single origin, but they have the added benefit of potential profit even at lower price points for the roaster. 

The key here is to understand the balance between the cost of each component, its relative contribution to the flavor profile, and having a target number in mind. This will help you adjust your percentages during R&D to achieve the best possible results. I like to use a very simple spreadsheet formula to help me figure these things out.  

The Blend Worksheet Example  

  Coffee  Cost /KG (green)  Percent in Blend  Cost In Blend (/KG) 
  BRAZIL  6.00  50%  3.00 
  Ethiopia Yirgacheffe  10.00  20%  2.00 
  Sumatra Mandheling  8.00  30%  2.40 
  sum:    100%  7.40 


Cost * Percent 

= Cost in Blend /KG 

Add Column to Confirm 100% total 

Add Column to Discover the Blend’s Total Cost /KG  

In this example, we’ve managed to keep the cost of goods for the final blend well below the higher costs of the expensive components, while still allowing them to contribute in significant percentages to the flavor. Using this formula, it becomes very easy to achieve the desired flavor profile while operating within the constraints of a financial limit. 

Brewing Your Blend  

It’s my opinion that one of the most frequently overlooked steps in many QC programs is brewing the coffee as its intended to be served. The cupping table is absolutely essential, don’t get me wrong, but when it comes to blending, especially, I feel it’s important to break out the lab’s auto-drip or espresso machine.  

Espresso specifically has a long tradition of use-specific blends. While Single Origin espressos take center stage at most next-wave cafes, the house espresso blend is a stalwart signature workhorse, one that can deliver consistently excellent shots and pair perfectly with milk for sweet cappuccinos and lattes.  

The art of excellent espresso blending can be accomplished in a couple of steps.  

  1. First, identify your intended flavor profile and keep it simple and straightforward. Do you want a big chocolatey body? A crisp citric acidity? A bold red cherry finish?  
  1. Now find coffees that match that profile, and brew them as espresso (by themselves first). This will help you identify the flavors that make it from the cupping table into the demitasse.  
  • Typical resting periods after roasting for espresso service may be as little as 2-3 days and as many as 12-15, so keep your preferred off-gassing profile in mind when tasting. At the Crown, we tend to prefer longer resting periods but are flexible enough to make short timeframes work with the appropriate dial-in protocols. This is a key ingredient – be sure to dial your coffees in individually. You’ll quickly find which components are easy to work with and which ones will cause headaches for your baristas.  
  1. Keep your selections limited to two or three coffees, four if you must. Blend in two distinct styles: (try an equal part blend next to a 60%/20%/20%, e.g.), note your preference, and adjust in ~10% increments, as necessary.  
  1. Label your components’ major flavor profiles and contributions to the final blend. This will help you replace them when they run out. Instead of needing to have that Costa Rica in January (which may not be available, and if it is, might taste faded) to supply the milk chocolate and ripe peach flavor, look to a freshly landed alternative with a similar cup profile.  
  1. Keep in mind that, as Alex Taylor once corrected me, “Good baristas make good espresso.” Get a professional involved to help you understand the coffee’s ease of use, and to make those kinds of micro-adjustments to bring out the best in your blend during QC so you can offer it with confidence to your customers.  
  • Be sure to note your brewing specs and keep them on hand to check at regular intervals, giving you assurance of blend consistency.  
  • While your own café may be up for the task of tricky dials, keep in mind that for wholesale purposes an easy-to-dial blend can make all the difference to a less experienced client.  

When to Blend?  

One of the biggest choices for a roaster’s blend is whether to mix the coffees before or after they are roasted. There are pros and cons to both approaches.   

When to Blend? 

Before vs. After 

  Pre-Roast Blending  Post-Roast Blending 
Roast Homogeny  Yes, if green is well selected  No 
Green Coffee Variations May Cause Uneven Roasting  Yes, if green if poorly selected  May Be Mitigated 
Ease of R&D  Must Plan and Roast Blends in Advance for Testing  Able to Blend on-the-spot for QC with Enough Available Roast 
Efficiency in Production / Storage / Packaging  Yes  No 
Brewing / Extraction Variations Due to Roast Level Variance  No  Likely 


Pre-Roast Blending has several attractive features for roasters, the first being ease of use across production. If green is weighed and blended accurately before roasting there is no need for additional blending equipment or labor, as the roasting machine will homogenize the beans during the roast. Also, a single roast can potentially fill your orders, and any roasted storage prior to bagging will require only a single storage unit (barrel, bin, Cambro, etc), saving both time and space.   

Drawbacks to Pre-Roast blending include the difficulty of R&D (in that the QC team must taste the blends, prescribe adjustments, roast again, and wait to taste for sufficient resting time). Roasting coffees together can present challenges if the physical metrics of the green are very different (i.e., if they vary in moisture, density, and/or screen size).   

This can result in uneven coloration for the final product, and best practices indicate using coffees of similar green specs for best results. This can be restrictive if you wish your blend to be Sumatra (usually large beans with low density and high moisture) and Ethiopia (small, very dense, and dry), for example. However, if good practices are followed, you’ll end up with a blend that extracts very evenly due to its consistent roast development.  

On the flip side, post-roast blending offers far more flexibility for the R&D team, as the roasted products can be blended on the spot for new iterations during development. While differences in green metrics during roasting present fewer challenges (since each coffee is roasted independently) the final blend may still contain variations in extraction when brewed due to the multiple roasts involved. 

Post-Roast blends take significantly longer to create after roasting depending on the number of components, which must be weighed and blended on separate equipment (or in the cooling tray of a roaster when not in full production). While this does require additional labor and equipment, the attractiveness of easy changes at the QC level and the qualitative benefit of individually tailored roast profiles for each coffee make post-roast blending a popular option.   

The right choice for your blend will come down to weighing your priorities for quality, development, and production.  

How Many Coffees? What Percentages?  

Opinions on the options for a number of coffees in a blend, and at what minimum percentage, will equal the number of people of whom you ask the question.  

15-part blends, as ludicrous as they may sound, exist for the sole purpose of flexibility – a single component may be switched or altered with relatively low impact on the final flavor.  

However, most seasoned blending professionals will recommend two or three, at most four parts. This keeps things simple for development and production, makes flavor profiles easy to identify, and gives those beans the best shot at falling in the right proportions in any given portafilter or pour-over.   

At less than 25% in a blend, the chances of making a real impact in the final flavor profile begin to fall off. This is especially true for espresso, where you begin to risk disproportionate representation because of the small dose. The silver lining here is that if you have a risky, poor tasting, or expensive coffee, using it in small percentages in a blend where the other components are overrepresented and flavorful can help you move inventory without negatively impacting your quality if the need arises.  

I often encourage people to entertain the idea of equal-parts blends due to the simplicity of production they confer. Other popular baseline percentages might include the 70% – 30% two-part blend and its three-part mirror, the 50% / 30% / 20%. These options are frequently seen for espresso, where a rich creamy base occupies the high percentage component and a bright, juicy coffee (or two) fall into place as minority stakeholders, lending – you guessed it – balance.   

Common Blends  

Mocha Java  

This relic remains on menus worldwide as an homage to some of the very first coffee available on international markets in the 18th century. Originally a blend of Yemen (the “Mocha” component) and Indonesian coffee grown on Java, the definition has broadened to include Indonesian coffee at large (Sumatra is a common option) and natural process coffees of medium fruitiness (Ethiopian Grade 3s and 4s make a common appearance). Roasting is traditionally a little on the darker side for this blend, and percentages typically close to 50% / 50%.  

The American House Blend & Breakfast Blend  

No standard definition of these coffees exists, but because of the United States’ relative proximity to our western hemispheric neighbors, many so-called “house blends” and “breakfast blends” incorporate majority or exclusively American grown coffees from Mexico on down to Brazil. East African and South Pacific coffees make occasional appearances, usually in minority percentages.  

Breakfast blends in particular offer interesting opportunities for pairing with pastries and other morning snacks. The roast level of a breakfast blend is hotly debated, and largely it will fall to the individual roaster to decide on their style and accompanying marketing materials. However, if you do have a café with food, consider this your opportunity to profile a coffee for pairing with your choice of tasty treats.  

The Dark Roast Blend  

Many coffees make great dark roasts, but crafting a creative dark blend can be challenging depending on your chosen components. The best options tend to be bold in flavor and heavy in body with high-density green to help the character stand up to the extra lick of the flame. Our traders recommend Colombia, Sumatra, Timor, New Guinea, and Uganda as excellent choices. Blend in the percentage you prefer and take it to second crack (and beyond)!   

Espresso Blends  

Traditional (some might say “old school,” others “Northern Italian”) style medium-roast espressos incorporate a hefty bodied but mild coffee (Brazils are great for this) with a light caramelly sweetness (think a washed mild coffee, like a Mexico, Honduras, or Peru) and a hint of something special (perhaps a natural Ethiopia, a juicy Costa Rica, or a bright clean Colombia).  

Robusta has been used as a minority component of many espressos for ages. This is due to Robusta’s propensity for producing an exceptional head of crema, as well as the jolt of extra caffeine and a bit of desired bitterness.   

Other common blends  

Some roasters choose to blend multiple roast levels of a single coffee for complexity. Some like to experiment with regionally specific coffees For as many carefully crafted blends exist, perhaps an equal number of “happy accidents” occur. Don’t be afraid to experiment and let necessity be the mother of invention.    

Final Thoughts on Transparency  

Blending coffee is fun, can be tasty and easy, and is also an immensely pragmatic undertaking. Labeling coffee blends can be a little tricky, however.  

First and foremost, we encourage the highest degree of transparency possible in your blends. Trade secrets in blending are mostly a thing of the past, and I’ve seen coffee roasters publish their exact blending percentages in recent years. While this may seem shocking, there’s also a next-to-zero chance that the roaster next door is looking over your shoulder to cheat on your blend.  

Transparency in labeling has the primary benefit to the producer of offering credit where it is due, and the secondary benefit of engendering trust between you and your customers, and the greater roasting community at large.   

That said, some scenarios require more opacity, specific to the way some blends must remain on shelves year-round, year after year. This can require a universally applicable label that might specify regions rather than countries to allow flexibility.  

It’s a difficult tightrope to walk, but one that deserves your attention and thought before you roll out the final product  

Source: by Chris Kornman

Back to blog