Which Beans For Which Grinder?
Fact 1 - Different bean varieties are grown in different countries, climates, humidity levels, altitudes, temperatures, and so on. Brazil is different to Ethiopia.
Fact 2 - Because of these different climates, etc - each bean will grow at different rates. Hell - the same bean grown in different locations will grow at different rates. Some faster than others - some slower than the rest.
Fact 3 - these different rates of growth mean different densities. A slow growing coffee bean will be denser than a fast growing one. That’s simple physics … and biology … and biochemistry … and probably ecology also. Actually it's not that simple, like anything else in this complex, beautiful, natural world - but it is basically true that faster growing things are less dense than slower growing things. Faster things lay down less "stuff" than slower things. Fast flowing rivers do not have sandy/muddy bottoms.
Fact 4 - your grinder (whatever it may be) will grind denser things differently to less denser things. Now - that IS physics.
Fact 5 - since your grinder behaves differently with different densities of things - it will grind those things differently.
Fact 6 - since the taste of your coffee is dependent - partly - on the grind of your beans (from expresso to cafetiere to filter) - ergo, the grinder you are using will generate a different taste profile dependent on the bean. And if we can throw another ergo in here - there will be a bean type/variety that is best suited to your grinder.
Fact 7 - tada!! Er .. That's it!
Difference Between Built In Grinder And Standalone Grinder?
So, we have proven that the type of grinder you have is better suited to the type of bean that you buy. If your next question is why is my built in grinder not the same as every other grinder? You only need to type in coffee grinder into your local search engine of choice and you will see that you can spend anything between 50 pounds and 5000 pounds on a coffee grinder. We’re not trying to flog you a coffee grinder - although we'd be happy to source what you need at a very reasonable rate ahem - but we would NOT recommend spending 50 pounds. Even we would be hard=pressed to justify spending 5000 pounds. Why the difference?
A grinder is nothing unless it grinds. And to grind it uses burrs. To produce a consistent, great coffee - you need a consistent, great grind. Consistency in the grinding world means that the beans are ground to a consistent "Goldilocks" particle size - none too big, none too small, all of them "just right". To get all your particles "just right" - you need excellent burrs and an excellent motor. Excellent burrs and excellent motors are not cheap. Burrs that grind quickly, efficiently, and do not wear away within a few months, are definitely not cheap. In very good coffee shops they will often pass the coffee grounds through a specific 800 micron sieve to ensure the quality of the grind. Those same coffee shops will then brew the coffee and measure with a refractometer the level of Total Dissolved Solids (TDS). A great cup of coffee should have 1.3% TDS. You only get 1.3% TDS with a consistent, excellent grind. You only get a consistent, excellent grind with a consistent, excellent grinder … We'll leave that there.
Right - so there you have it. The reasons why you should look after your grinder. As for what beans are best suited to your bean-to-cup machine - well, that’s for you to figure out! However we would start somewhere like Brazil. Bean-to-cup machines have all-purpose grinders which are most likely ceramic, conical burrs. We doubt they will be kitted out with titanium burrs like the best ones. So with these all-purpose burrs they will be most consistent with low density, more darker roasts. We would recommend our Gunpowder Blend as a dark, but not too dark! roast which is porous enough for even a basic bean-to-cup machine grinder to get at least decent extraction.