Is it better to pre-blend or post-blend coffee?

Blends are a popular option among specialty coffee roasters, providing consistent and repeatable flavour profiles throughout the year.

Unlike single origin coffees, they create a product that customers know will be the same each and every time they buy it. This can help brands build their reputation, promote trust, and boost loyalty, among other things.

However, creating a blend is not quite as simple as it might seem. It requires an in-depth understanding not only of the coffees being used, but of factors such as blend ratio and batch size. It also depends on the key decision of whether to blend the coffee beans before or after roasting.

While some maintain that pre-blending helps save time, others claim that it limits the ability of roasters to derive the best flavours from each bean.

I spoke with WBC-certified judge and WCE representative Danilo Lodi to get a deeper understanding of the difference between the two.

What is a coffee blend?

A coffee blend is a mixture of two or more single origin coffees. They are generally made with no more than five different coffees, with one coffee making up a significant proportion of the blend, known as the “base”.

It is a broad term, as some coffee blends consist of beans from different regions in the same country, while others are from different countries altogether. This is in contrast to a wine blend, which is a blend of different grapes usually from the same vineyard or village.

“Pre-blending is when you put all the coffees you’ve selected for your blend together inside the roaster.”

One of the main advantages of a blend is that it helps to balance, accentuate, or downplay notable characteristics in certain beans to create a more well-rounded and consistent coffee. Many specialty roasters will often mix lower quality beans with higher quality ones, which can also help keep down costs.

To create a blend, roasters either have to mix the beans before roasting or after roasting. This is known as pre-blending and post-blending.

“Pre-blending is when you put all the coffees you’ve selected for your blend together inside the roaster,” explains Danilo Lodi, an experienced roaster and WCE-certified judge based in Brazil. “You’ll roast all the coffees together in the profile of your choice. Post-blending, on the other hand, is when you roast all the single origin coffees separately. After that, you’ll mix all the coffees together in the percentage [ratio] of the blend.”

Danilo says that the decision to pre-blend or post-blend largely comes down to the preference of the roaster, as each blend will be affected by variables like bean density, humidity, screen size, and varietals.

The pros & cons of pre-blending

Some specialty roasters claim that pre-blending promotes interchange, which is when beans give off and absorb each other’s flavours and heat during roasting. 

It’s also believed that pre-blending promotes blend integration by smoothing the beans, and that it negates over and under roasting while delivering a smoother and richer outcome.

Danilo says that pre-blending is a time saving option for roasters as they can roast all the coffee in one batch. He cautions, however, that different bean sizes, varieties, and regions — as well as beans that have been processed differently — will roast at different paces.

This means that some might be ready earlier than others, resulting in a blend with an inconsistent flavour profile.

Pre-blending is recommended in cases where a recipe has already been established, or when the beans being roasted share similar physiologies. Although no two types of beans will roast exactly the same, pre-blending will certainly result in a more uniform blend.

Another practical benefit of pre-blending is that it can make the production process easier. By weighing and blending the coffee together before roasting, you won’t need access to additional roasters or equipment.

The pros & cons of post-blending

Many roasters believe that post-blending preserves the unique characteristics of each bean, while balancing body, acidity, and sweetness. Others, meanwhile, feel that post-blending also reduces the risk of inconsistent development. 

Danilo agrees, saying that post-blending allows the roaster to respect the time and profile of each bean individually. By roasting coffees separately, you end up with a more homogeneous blend. 

Post-blending is beneficial in cases where you’re experimenting with new coffees and untested blends. For example, you can create and revise combinations on the spot. However, this is incredibly time consuming, and you’ll also need additional equipment and hands to help you weigh and blend different coffees.

The Sweet Marias roasting team, for examples, maintains that post-blending can be used to create a melange blend, which is basically a combination of coffees roasted to different degrees. A melange blend could help you retain the carbon flavours of a dark roast as well as the acidity of a light roast — all in one blend.

“If you’re focused on offering high end specialty coffee, you might consider taking more time to add more value to a post-blended coffee,” says Danilo. “This will create a coffee that’s more consistent for your customer.”

However, he recommends that roasters with high volume demands use pre-blending instead, and that they select coffees with similar sizes, densities, and humidity levels to make the process easier and less time consuming.

You could also consider offering two different blend types: standard blends and seasonal blends. Standard blends can be kept in stock throughout the year, and you can supplement them with a rotating list of seasonal or experimental blends.

No matter which option you choose, keep in mind that your blend outcome will only be as good as the coffees added to it. While blends can enhance or mask certain qualities in a coffee, only quality coffees will give you a blend with staying power, allowing it to be offered (and stored) for longer.

What about packaging?

Once you’ve selected a pre or post-blend, you’ll spend plenty of time carefully choosing the right coffees to combine and the ideal ratio to combine them in. Sadly, however, this effort will be wasted if you don’t do all you can to preserve the coffee once it’s ready for sale and consumption.

Coffee is a sensitive product. It’s packaging must allow atmospheric exchange to take place: carbon dioxide must escape and oxygen must be kept out. Your packaging will also need to have good “barrier” properties, providing protection against external heat, light, and moisture.

Beyond these benefits, packaging can also differentiate your coffee from others on the market. It can also help your limited edition or seasonal blends to have more of a visual impact, for example, provided that they contrast against your usual branding.

Investing in a one-step packaging solution could boost the sales of your coffee blends significantly. A packaging specialist can steer you towards the right packaging shape and size for your needs and brand it appropriately.

By integrating degassing valves and seals, you’ll be able to package your coffee right after roasting, sealing in all the flavours and notes you’ve worked so hard to develop.

For many roasteries and cafés, coffee blends are integral menu items that cater to a wide range of palates and preferences. They’re versatile, well rounded, and timeless, and with the right packaging, they can be best sellers.

At MTPak Coffee, we believe that coffee packaging can be the difference between a good brand and an iconic one. With our expertise, we’ll help you to create unique designs that will appeal to even the most discerning customers, while preserving the most important thing of all – the quality of your coffee.

For information about our sustainable coffee bags, contact our team.