We get a lot of questions about what makes a good drip grinder Vs. espresso. We often get questions about the best grinder for both applications as well. There are a lot of things that go into a grinder, so we wanted to provide some tips for what makes each type tick.
Drip Grinders
What makes a great drip grinder is consistency. It's fairly well understood that larger burrs can lead to finer grind. In the case of a great drip brewer we're more interested in control settings and consistency than getting as fine as possible. Because drip brews require less fine adjustments, stepless controls are additional nice-to-haves, but not a necessity. What is important is consistency. A grinder with a decent sized (40mm or so) burrset and conical shape will provide quality, consistent grounds.
Ultimately the point we're getting to here is that drip brewing is simply less demanding than espresso. This means that buying a drip grinder should be a much smaller dent in your budget than an espresso grinder.
Espresso Grinders
For espresso, consistency and control are important, but power is required as well. Espresso brewing requires a highly precise grind due to the pressure at play. This is especially true when using unpressurized portafilter baskets, because your grounds are helping to create that pressure. This means that you need very fine grounds that are also very consistent. The best way to get this is with larger (50mm or larger) burrs. Finding a compromise between burr size, shape, and price is key here. This need for more fine grounds is also why some grinders just can't to drip and espresso. Such a wide range of positions isn't possible for every burrset to do well.
Another important facet here is control. Unlike other brew methods, desired fineness will shift from roast to roast. Some coffees will want a slightly coarser or finer grind depending on origin, roast level, and more. This all means that super fine adjustments are very important. You'll also need to carefully dial in your grinder for the best results for espresso whenever you refill it with a new bean. Which leads us to our conclusion...
Why Not Both?
Instead of hunting for a grinder to do both drip and espresso, consider budgeting for a separate one for each method. This may seem like overkill, but switching from your carefully dialed in espresso grind to drip and then re-dialing it is a large frustration. Even if you carefully mark where your espresso grind is set, it can be quite difficult to find the spot precisely. On the other hand, drip grinders are so comparatively affordable that by sacrificing a bit of budget for a separate one you can really make your coffee setup more usable.
It's for this reason that we hesitate to recommend grinders that can handle both types of brewing, even if they technically do exist. Just make your life easier by adding a small drip grinder to your kitchen! We're sure it'll save you some headaches.