The Mortar & Pestle – Seasoning

If you’re serious about ethnic cooking, there comes a point where a mortar & pestle will become a critical part of your kitchen arsenal. The more you cook certain styles of food (Thai, Peranakan/Nyonya, Mexican, etc.), the more you will find that modern shortcuts – coffee grinders for spices, food processors for grinding pastes – remove a level of control in working ingredients and can actually negatively impact flavor.

Tossing spices and liquids into the Cuisinart is an afterthought. Pounding a rempah to be used in a curry is a deliberate act. You have to take the time to think about each ingredient as you add it to the mortar – you watch the texture change and smell the aroma develop as oils are released. With practice you learn how subtle changes in the way you pound and grind affect the final product.

I’ve been working without a decent mortar for a while now (my old one is garbage) and my frustration got the better of me. I finally found a granite mortar & pestle that I liked (not too deep and wide enough to be able to work with a decent amount of ingredients). I’ll go into more details about working with it in future posts – this post is about seasoning a new mortar.

Think of a granite mortar like a cast iron pan – you have to season it before you can use it. It’s not difficult  but it does take a little bit of time. The upside is that you get to spend a little time familiarizing yourself with the tool in the process.

Step 1

The first step is obvious – wash it out with plenty of water (like cast iron – NEVER use soap).

Step 2

Throw in a few cloves of garlic (peeled) and pound them into a paste. This is a good time to get a feel for how you are supposed to work with a mortar. Don’t start pounding the crap out of everything – you’ll have garlic everywhere – your hair, on your cabinets, floor, ceiling. Everywhere. Start off gentle. Hold the pestle at an angle and work your way around the bottom. Pay attention to the ingredient – it will tell you when to pound harder or more gently.

You are working toward a fine paste – get it up onto the sides of the mortar. You want to cover the entire inner surface. Once you have the whole surface covered – leave it. This sounds weird, but just let it sit on the counter (12-24 hours). You can cover it with plastic wrap to keep things out of it (and the aroma down), but leave it be.

Step 3

After the garlic as set for a while, wash the mortar and pestle again. Remember – water only. The garlic in mine had taken on a greenish hue. Don’t worry about it – just rinse it out really well. Now it’s time for rice. Take a little wet rice (uncooked) and add it to the mortar. Remember that part in step 2 where I said to be gentle? Now is where we see if you were paying attention. Gently begin to pound and grind the rice. If you’re careful you’ll only lose a few grains of rice. More likely you’ll lose quite a bit.

The idea is to work the wet rice into a fine paste, again coating the entire interior surface.

Take your time. Uncooked rice is hard, so it’s going to take a while to get it broken down. Don’t worry if you don’t feel like you’re doing it right. You get to do this again (and maybe again). Your first batch of rice will turn grey. What you’re doing here is grinding loose grit out of the mortar and the rice paste is picking it up.

Wash the mortar again (water only) and do another batch of rice. Repeat this process until the rice paste stays white. Remember this step, as this is how you will clean the mortar if you get food sticking to it or if you use a strong or heavily colored ingredient (like achiote).

Step 4

Getting closer. Rinse and dry the mortar, then add some coarse salt. I used sal grosso.

In this step you’re grinding – you want to work the salt around the mortar, grinding it as fine as possible.

Step 5

Rinse and dry the mortar again. Your mortar is now ready to use. You can grind a few other spices in at this point, but in my mind they don’t really stick around as “seasoning”.

These are white and black peppercorns. Remember that part about gentle? This is good practice for that. You need to coax the peppercorns to crack before you can really start working with them.


  1. Why do you need the garlic step at all before the rice and why the long wait with the garlic paste in the bowl.

    Also, I was looking at this type of thing on amazon and they look a lot less shallow than yours, as you mention something about.

    What makes the more shallow ones better?

  2. Techincally, you don’t need the garlic step – it’s just a seasoning step (much like oiling a cast iron pan). Some cultures use different seasonings (turmeric, sesame, etc.). You let it sit because the stone is porous – this allows the oils in the garlic to penetrate.

    Mine isn’t that shallow – it’s probably more of a camera angle issue. Thai mortars tend to be much deeper and narrower, though I’ve seen Thais using mortars similar to the one pictured. I just happen to prefer a wider bowl. I find it easier to work the ingredients – it’s just a matter of preference – not necessarily better.

  3. I found a mortar and pestle that looks exactly like this at Target store which is now carrying ethnic cooking utensils! 1/15/2013

  4. Dave – how does the initial seasoning (such as your use of garlic) affect the flavor of future herbs, pastes, powders ground in it? Does the garlic add a strong scent/flavor, or does it only tweak the character of what you produce?

  5. There is no strong flavor or scent to the mortar after seasoning (or I’ve grown numb to it). Typically, you’ll use ingredients in the seasoning of the mortar that you’re going to be using anyway. If my intent was to use the mortar for grinding something like cocoa nibs, I definitely wouldn’t use garlic (or any other savory ingredients in the seasoning). But as I primarily use the mortar for cooking Asian foods, and garlic is in pretty much every cuisine’s “holy trinity”, it makes sense.

  6. I too found this same M&P at Target and bought it (only then did I start researching M&Ps on the internet…).

    I have not seen any discussion that addresses “the grit” in more detail. So I figured I’d offer some. I don’t want to ingest the grit either. Being that granite and marble are probably physiologically inert, I’m not so sure it would have any great negative adverse health effects unless for some reason it collects in ones intestines and doesn’t pass. It’s more the psychological impact!

    Here’s my suggestion to alleviate a majority(?) of grit. First of all, be aware that the grid is simply the particles of the stone itself being ground off from both pieces (mortar and pestle) when you grind on it.

    PS (Stone-on-Stone): Grind on any stone using a another piece of stone and it WILL wear/grind off particulate crystals of stone from one or both pieces.

    As noted, one does not want the interior of the mortar to be highly finished else it defeats the purpose – which is to create friction and hold the materials in place such that it is not simply pushed in front of the pestle but instead ground by it.

    On the specific set shown on this webpage, it does not appear that the factory cuts on the interior surface of the mortar were really polished, maybe it was de-burred, but that’s all. Likewise the balled ends of the pestle are not truly semi-circular. Look closely and you’ll see that the shape is only a rough cut. These surfaces may even have flats, etc., so the grinding surface on both pieces is still relatively rough out of the box.

    The interior surface of the mortar has excess “relief.” This is the relative difference in “depth” of stone between the groves and peaks of the ridges that circle the interior of the mortar as a result of the stone-milling process. Every time one uses the M&P, and certainly if one applies enough elbow-grease (pressure, and it doesn’t take much), the pestle will grind upon the ridges along the interior of the mortar and wear them and itself down. This grinding process produces the grit that all initially observe on a new stone M&P.

    Solution: To reduce and actually remove at least some of the “excess” relief and minimize grit-production, dry grind the M&P multiple times with some pressure to take down some of those high relief edges. Not to worry – the non-polished surface will retain sufficient roughness to serve the purpose for which it was intended. It only takes a minute or so to dry grind and you’ll see the powder grit build-up on both the mortar and pestle. Rinse it clean (use a brush if you wish) and let it dry thoroughly, then do it again. The number of time you do this is your choice. In reality you would never reach a point of zero grit since, as I stated above, one can always produce a grit with enough pressure. The purpose here is simply to reduce the high relief of the ridges which will in turn reduce the high volume of grit that results from the excess roughness on a new set. This effort will also grind the initial amount and the shape and condition of both the mortar and pestle to degree that will produce a better “fit” between both pieces.

    For those that have other stone M&P sets, you may see that the finish (polish) on the interior of another mortar, though not glossy, that has a more refined finish. Bear in mind, providing that both the M&P are made of stone, no matter the degree of polish, one can always grind with enough pressure to produce some grit. Preparation of the foodstuffs is a balance of pressure to minimize grinding through the material and avoid direct stone-on-stone.

  7. You know – I don’t know. I don’t notice any odor of garlic from the mortar. That being said, I don’t use my mortar for anything sweet. If I’m using cinnamon or anise, I’m probably using it in a savory dish.

  8. I just used these steps and there is nearly zero garlic scent left over. The garlic scent was nearly gone after the first rinse. 🙂

  9. I’m not sure, but the acid in garlic, H2SO4 (sulfuric acid, the same thing that makes onions potent), if I’m right, will start to break down some of the microscopic rough edges of the granite as it sits, which leaves the end result less porous.

  10. Is this granite or volcanic rock?

    Most of the granite ones I have seen, in SE Asian stores, are smooth inside.

    Yours does not look smooth.

    It looks more like the traditional Mexican molcajete, made of volcanic rock.

  11. BuHi,

    You say you would not grind cocoa nibs in a mortar that’s been seasoned with garlic. For argument’s sake, how would one season a mortar that’s earmarked for grinding cocoa and sweet spices like cinnamon?

  12. That’s an interesting question. I think there are two parts to it – 1. Removing the loose stone and grit, and 2.sealing pores in the stone.

    You want a little bit of abrasive for the first part. If your doing this for cocoa, I don’t know why salt wouldn’t work.

    For the second part, possibly a little neutral oil – or just grind some nibs?

  13. Well, I followed your instructions for seasoning my new mortar and pestle set. Great results. (Thank you!) With regard to the garlicky smell, I found that swabbing the pestle and mortar with lemon juice effectively deodorizes lingering smells. I found that this works like a charm after doing so and crushing whole pecans for brownies.

  14. My husband and I have been carting around a stone (maybe granite) mortar and pestle that he got at least40 years ago in Malaysia. It has gathered rainwater, dust and heaven knows what. We rescued it from a corner in the basement because I want to use it to make pesto. Have washed it out with water and will do the seasoning. Is there anything else I should do? And BTW, do you need two? One for the spicy/garlicky stuff and another for sweet things?

  15. Thanks for the post! Seasoning my M&P has most definitely enabled me to understand the amount of pressure needed for different results! If using a variety of spices is using the rice and salt method a good way to “cleanse” it so there are no left over tastes? I prepare a great variety of cuisines and would love to use the M&P as much as possible.

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