Knowing how a Mexican mortar and pestle (molcajete) is used will mean that you can become a discerning buyer. Of course, you may want one just for decoration in which case you can skip all this. Even many Mexican families have them on the kitchen counter as a reminder of bygone days, using the blender to prepare their sauces.
But if you are interested in using a molcajete, then perhaps the following considerations, gleaned from the molcajete makers themselves, from Mexican cooks, and from personal experience, will come in handy. Any comments, corrections, or additions welcome.
To begin with, describing the molcajete as a “mortar and pestle” is as generic as describing a frying pan as a cooking pot. Like cooking pot, which includes not only frying pans, but covered casseroles, sauce pans, stockpots, and so on, mortar and pestle includes very different tools for very different uses.* (I see another post coming up on the multiplicity of pestles and mortars).
For now, though, for most of us, the first mortar and pestle we encounter is likely to be the standard marble one, polished smooth inside and out. We are used to holding the pestle in our fist to pound spices or perhaps herbs. The motion is primarily an up and down smashing one.
You can use a molcajete for that. You can hold the pestle (tejolote) in your fist and pound. I do that for breaking up peppercorns, for example, and very efficient it is too.
But it’s not the major use of a molcajete in Mexico. There molcajetes are mainly used for preparing fairly small amounts of sauces (salsas).** The common, everyday sauces in Mexico are vegetable purees; their key ingredients are usually some combination of tomatoes (jitomates), tomatillos (tomates), and chiles.***
Now tomatoes, tomatillos and chiles all have thin, but tough skins.**** And you can bang away on those as long as you like and you are not going to break them up.
What will break up the skins of both red and green chiles, say, is grinding or shearing them laterally along a rough surface. So the fact that molcajetes are made of a rock with pores instead of smooth marble or granite is not an unfortunate accident. It’s a deliberate choice. Only in a few places is just the right rock available.
And you are going to use the tejolote to shear, not pound. Instead of holding the tejolote in your fist, put your palm over the upper end and hold the broad base with your fingers. Then using your wrist as a pivot you can twist the base, pushing the chile over the rough bottom or sides of the molcajete.*****
The photo below shows how the tejolote fits in the hand; the two middle fingers (invisible) almost reach the bottom. (Of course, I’m just showing it in a horizontal position because it was easier to photograph.)
Now you will understand what you are looking for.
Look for a tejolote that is long enough for your fingers to grab when you have the top in the palm of your hand. If the tejolote is very short, look for another molcajete.
Look for an interior that is rough to give purchase to the ingredients so that you can break them up. Costco is selling molcajetes made in China. They are the right shape but the wrong rock. It’s a rock, probably granite, that can be and has been smoothed out. That’s find for pounding, not good for Mexican sauces.
Look for a deep bowl to allow you to rotate the tejolote without spilling the salsa over the side. It’s quicker and easier to make a shallow bowl, so be wary of those.
Look for a fairly narrow and even rim of about half to three quarters of an inch that you can grab for stability while you are grinding. It can be flat or rounded but should be well defined.
Look for one that is symmetrical and nicely finished. The legs should be the same length, evenly spaced, and the exterior and the interior should be as smooth as the porosity allows. Or put another way, the surface should be rough but not uneven since the latter impedes grinding (and makes it more impossible to cure the molcajete).
Here are photos of molcajetes from various parts of Mexico. As you can see they are all much of a size to nicely accomodate the twisting of of the hand. Little molcajetes are fine for a small amount of (say) a very piquant sauce. They are not much good for making enough sauce to feed a whole family or to use, say, to make enough salsa to cook a pork in salsa verde. Although the tejocotes vary in form they are all longer than they are wide and have a broad base for grinding.
One more thing that you can’t see here. The rock from which they are made varies in porosity and hardness. The molcajete makers use the softer rock for toys and for their sons to practice on when they are learning. But of course it’s quicker and easier to make a molcajete from the softer, more porous basalt. So there is a temptation to pass these on to those who are not used to using this utensil. If you are unlucky enough to get one of those, it is going to be very difficult to cure.
In short, a molcajete is a very finely-crafted tool for very specific purposes. There’s nothing primitive about the design, even though the production may be artisanal. So choose carefully. Compare, for example, the one below with the photos and discussion above. The bowl is shallow, the rim ill-defined, and the tejolote short.
It’s too bad that so many sold in the US are not up to snuff. It’s easy to tell a story about why. Customers are not experts in their use. Stores need their markup. The molcajetes are heavy to transport. And the amount going to the makers is probably very small. I would love to know more about the middlemen such as Imusa.
When you have found a nice molcajete, you need to cure it (get rid of remaining rock fragments) before you use it. First take a stiff wire brush (perhaps even on an electric drill) and get rid of all the fine bits of rock. Then put in rice and grind in batches until it comes clean. If this doesn’t happen after a certain length of time, then you probably have a second rate molcajete.
** For excellent, accessible explanations of and recipes for Mexican sauces, see Truly Mexican by Roberto Santibañez.
*** Indigenous Mexican cuisine relies on grinding rather than cutting. Knives are used mainly for sauce bases that are of European origin. Thus all those Mexican recipes that start with chopping garlic, onion and tomato, or the pico de gallo sauce often thought of as a Mexican sauce north of the border, I suspect to come from the Spanish tradition in Mexican cooking.
****It’s true that in sophisticated Mexican cooking the skins of tomatoes and tomatillos are often removed after dry roasting but this is not usually done in the villages in my experience.
*****There are a lot of pretty bad you-tubes in English with supposed experts pecking away with the tejolote. This by Yuri Gotari in Spanish is better.