Blind blending is a method used by the Karvan Coffee roasting team to explore the potential of particular coffees and their flavours to create new blends or make changes to existing ones.
This technique was used to create this year’s Christmas Blend, and we sat down with Brad (co-owner of Leaf Bean Machine and head roaster for Karvan Coffee) to find out more about the process.
What are the steps involved with blind blending, and how long does it take?
The whole process can take up to a month or more to create a new blend. The first step is deciding on which green beans we intend to use then, once the coffee samples arrive here at the roastery, we then have to roast each sample. The roasted coffee then needs to rest for around 24 hours before we can begin with the blind blending session.
Once rested we then grind each sample and add a measured amount of hot water to each one. This stage of the process is very similar to our cupping sessions: a method we use to score samples of every batch of coffee we roast each week in order to maintain consistency in our coffee.
We then break the crust of the coffee and remove the top layer. Each sample is tasted, where we apply scores according to the taste and aroma of the coffee. This part of the process is the same method we use each week during our cupping sessions to taste and score every single batch of coffee we roast. This helps with quality control and helps us to ensure that we maintain consistency across all our coffee range.
When constructing a blend we are looking for components that will add a solid base, along with individual fruit and origin characteristics to the cup. But most importantly they need to shine together as one. With this in mind our roasting team will come up with a list of different ratios to try.
For our blind blending we use a syringe and set of scales to measure out the liquid coffee according to the ratios we wrote down. The sample could consist of one base and one fruit component or two base components and one fruit component, the options are endless and it really depends on what each person thinks is the best combination.
We taste and score each new blend on the table, discuss the scores afterward and eliminate the samples with low scores. This method can be repeated several times until we are able to decide on the winning combination or combinations. We then test the final selections as espresso and make our final decision based on how the coffee works with different milks and brewing methods.
Is this technique only used for special blends like the Christmas Blend?
No we use this for all our blends. When I am looking to create a new coffee (like the Christmas Blend) or to make changes to our existing blends, then this is the method that I would use.
Can you tell us which coffees you have used in the Christmas Blend this year?
No – it’s a surprise! I can say that you’re definitely going to enjoy it though.