Each week J. Kenji Lopez-Alt will drop by with a list of tools or a tool you might want to stock your kitchen with—if you haven't already. Kenji also writes The Food Lab column here on SE. You can fan The Food Lab on Facebook for play-by-plays on his future kitchen tests and recipe experiments.—The Mgmt.
As I've pointed out in my 3rd Guide to Essential Kitchen Hand Tools, a mortar and pestle is really the best way to grind spices if you are only an occasional spice-user, and don't very often use more than a few tablespoons at a time. It's quick, effective, easy to clean, and gives you great control over the finished product.
But just this past weekend, I found myself with 18 pounds of brisket, 22 pounds of ribs, and 20 pounds of pork shoulder, all of which required a rub before an all-nighter of barbecueing before the Fourth of July. That's an awful lot of grinding, and for times like those, it calls for breaking out the big guns: an electric spice grinder. For all intents and purposes, a spice grinder and a coffee grinder are essentially the same rebranded product, so we won't distinguish between them in our comparisons.
Now when it comes to selecting a grinder, there are basically two things to consider: power, and design.
Spice grinders come in two basic formats:
The Coffee Grinder from Krups ($19.95, pictured at top, right) is an all-in-one unit where the spice chamber blade mechanism, and motor are all housed within the same plastic housing. The only part that comes off is the lid, which also features a button that activates the motor. You add your spices to the metal chamber, fit the lid on, press the button, and 15 seconds later, you've got powdered spices ready to go. This model has been around for decades, and it's the most common style of spice grinder on the market.
The main problem: since the grinding chamber is not removable from the plastic casing or the blade, it's very difficult to clean. Getting it wet is a no no, and forget about the dishwasher. The best you can do is to grind a bit of rice in it to help dilute and dislodge any spice debris, then wipe it out with a paper towel. Spices leave a slight aromatic residue, which isn't too bad if spices is all you use it for, but don't try grinding coffee in the same machine unless you like curry-flavored coffee (you should really grind your coffee in a burr mill anyhow).
The model on the immediate right is a more recent update on the classic design. This one is the Spice and Nut Grinder from Cuisinart ($39.95) (KitchenAid made a very similar model which seems to have been discontinued).
With this style of grinder, a removable metal cup holds the blade mechanism and the whole thing locks into place on top of the motor housing. A plastic lid is then placed upside down over the spice cup. Pushing down on the lid activates the motor. The great thing about them is that both the plastic lid and metal grinding cup are completely detachable and dishwasher safe, saving your coffee and spices from flavor contamination. The bad part is that in both the Cuisinart and KitchenAid models, ground spices leak out from between the metal cup and the plastic lid, falling directly onto the motor housing, which is once again non-waterproof and difficult to clean.
Not only that, but because of the large space between the blade and the base and the air currents created when spinning, spices are not ground particularly well in this style of grinder. Even after allowing the machines to run for a full 30 seconds, large pieces of spices remain.
To illustrate this, I ground a batch of five-spice powder in an all-in-one model and a model with a removable spice cup. Both batches of whole spices were identical, and both machines were allowed to run for exactly 30 seconds.
As you can see, the all-in-one model did a far superior job. The spices in the KitchenAid came out roughly ground at best, with several large pieces of star anise and cinnamon floating around in the mix.
The all-in-one clearly takes home the gold.
While there are other, perhaps prettier all-in-one models on the market, such as the Stainless Steel Cool Blade Coffee Grinder from Jura-Capresso ($24.99, 3.5 ounce capacity, 100 watts), the Coffee Grinder from Cuisinart ($22.95, 2.5 ounce capacity, 135 watts), or the Blade Coffee Grinder from Bodum, ($24.95, 1.6 ounce capacity, unspecified wattage), the French-made Krups offers the most power at 140 watts, and one of the highest capacities (3 ounces). Not only that, but it's the cheapest to boot.
So what if you don't want your coffee tasting like spices and are still leaning towards purchasing one of the removable cup models?
Simple: just buy two of the Krups, a black one for coffee, and a white one for spices. Since it's half the price of the Cuisinart, you'll be getting a much more satisfying grind for the same price.