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Lye. Isn’t that the stuff the Mafia uses to dissolve the bodies of those who’d made an unfortunate choice to use another waste disposal or vending machine company? Isn’t it drain cleaner, a deadly poison? So how on God’s Green Acre can lye be useful in the kitchen?
Relax. I am here to tell you that lye can be your friend, especially when it comes to curing green olives. A good lye cured olive, I have discovered, is uniquely smooth and luscious in a way that brine or water-cured olives can never be. Done right, they can be <gasp!> even better than a brine-cured olive or an oil-cured olive. Seriously.
Let me start by admitting that I was as terrified about using drain cleaner to cure olives as you are. Intellectually I knew it would work, and knew I’d eaten lye-cured olives before, as have most of us: They are those nasty black canned things also known as Lindsay olives. That knowledge, however, did not bolster my desire to do any lye curing anytime soon.
Then I did some research. I’d seen all sorts of references to how the lye cure — actually a cure in water that had percolated through wood ashes, which are a source of lye — being used “since Roman times.” Many hours of searching later, I found that the Roman agricultural writer Rutilius Taurus Aemilianus Palladius is the source of this, in his De Re Rustica, written in the 300s.
“Mix together a setier of passum, two handfuls of well-sifted cinders, a trickle of old wine and some cypress leaves. Pile all the olives in this mixture, saturate them with this paste in garnishing them with several layers, until you see it reach the edges of the containers.”
Passum is freshly extracted grape juice, so the lye in the ash-water interacting with this would make an interesting brew. There would be so much sugar going on in there that you could get both a lye cure and fermentation going at the same time. Freaky. Since then the Spanish have been masters of the lye cure. Most Spanish table olives are cured at least in part with lye, but their process is far different than that used in to make the hideous Lindsay olive. I am modifying a method I found in an agricultural book written in 1817.
Incidentally, other popular modern olives that use a lye cure include the French lucques, Italian cerignola and Spanish manzanilla.
First thing you need to know about curing olives with lye is that you must use fresh green olives. Not black ones, not half-ripe ones. The lye process softens the meat of the olive, so you want it as firm as possible. When you are picking your olives, watch out for olive fly. The larva of this nasty little bug burrows into an olive and eats it from within. Thankfully infested olives are easy to spot: They will ripen faster than healthy olives, and there is a tell-tale scar on the olive that looks like this:
Toss that olive. While the worm is not poisonous, I prefer my olives sans extra protein, thank you.
What sort of lye do you use? The traditional brand to use is the classic Red Devil Lye, which is an old brand of drain cleaner. But all the science I’ve seen says anything that is 100 percent sodium hydroxide works, so scan your drain cleaner well to make sure it is nothing but lye — Drano used to be this way, but apparently has additives now. Don’t use it. Buy “food grade” lye if you want to, but after much research, I can find no hard evidence that there is any difference between so-called “food grade” lye and non-food grade lye. I’ve used both.
Isn’t lye a deadly poison? Sorta. Sodium hydroxide is one of the nastiest bases we know of; a base is the opposite of an acid. On the PH scale, distilled water is the median, at 7. Your stomach acid’s PH is about 1 1/2 — enough to burn a hole through a rug. Lye’s PH is 13.
Bottom line: Raw, pure lye will burn the hell out of you, but it is not a systemic poison. That means that even if you eat an olive that still has a lot of lye in it — as I did — all you will taste is a nasty soapy flavor. If you eat a bunch of them, the alkaline PH in the olives will counteract your stomach acid and it might give you indigestion. That’s all, and that’s a worst-case scenario. That said, you need to be careful at that one moment you are moving raw, pure lye from the container to the crock you are curing into.
LYE CURING STEP BY STEP
Follow these instructions and you will be fine:
- Wear glasses if you have them. Wear long sleeves and pants and closed shoes. You will probably not get lye on you, but better to be safe.
- Pour 1 gallon of cold — not tepid, not hot, but cold — water into a stoneware crock, a glass container, a stainless steel pot, or a food-grade plastic pail. Under no circumstances should you use aluminum, which will react with the lye and make your olives poisonous.
- Using a measuring device that is not aluminum, add 3 tablespoons of lye to the water. Always add lye to water, not water to lye. A splash of unmixed lye can burn you. Stir well with a wooden spoon.
You’re done. You use cold water because the reaction between lye and water generates heat, and the hotter the lye-water solution, the softer the olives will become. Now that it is mixed, the lye solution can’t hurt you, so go ahead and add your olives.
Stir them in with that wooden spoon and put something over all the olives so they do not float. This is vital. Olives exposed to air while curing turn black. Don’t worry, they will absorb the water and sink in a few hours, but to start you need to submerge them.
Let this sit at room temperature for 12 hours. The alkaline solution will be seeping into the olives, breaking the bonds of the bitter oleuropein molecules, which then exit the olive and go into the water. After 12 hours, pour off the solution into the sink. It should be pretty dark in color.
Quickly resubmerge your olives in cold water. You want to minimize the exposure to air. You now have cured olives. I know, I know, a lot of recipes say to repeat the lye process another time — sometimes three more times — but that will destroy a lot of flavor; there are a ton of water-soluble flavor compounds in an olive that the lye solution washes away. Trust me. Your olives, unless they are gigantic, will not be overly bitter even after just a light, 12-hour lye soak.
Now you need to cleanse your olives. They will have a fair bit of lye solution in them now. Keep changing the water 2 to 4 times a day for 3 to 6 days, depending on the size of the olives. After 2 days, taste one: It should be a little soapy, but not too bitter. It’ll be bland, and a little soft. Once the water runs clear you should lose that soapy taste.
Time to brine. If you have large olives, make a brine of 3/4 cup salt to 1 gallon of water. And use good salt if you can. You will taste the difference. Kosher salt is OK, but ideally use a quality salt like Trapani, which is from Sicily. It’s not that expensive, but it is worlds better than regular salt.
Let the olives brine in this for 1 week. Keep them submerged, or you will get darkening. After a while they will sink. After 1 week, pour off the brine and make a new one, only this time, use 1 cup of salt per gallon.
Now you can play. The traditional Spanish cure would add some vinegar to the mix, as well as bay leaf and other spices. I’ve played with adding a touch of smoked salt, chiles, black pepper, coriander, mustard seed, garlic — think Mediterranean flavors.
But before you do this, taste your freshly brined olives. It will be a revelation. They will remain beautifully green, unlike brined olives. Salty, olive-y and very, very buttery. This is the Lay’s Potato Chips of olives. I dare you to eat just one.
Louisa: Good tip on the vinegar!
Barbara: So you did 17 pounds at one shot? Three tablespoons of lye is not enough to cure such a large amount of olives. I usually do between 1 and 5 pounds at a shot, and this amount of lye works fine. I am honestly not sure what to do about your dilemma. The only thing I can think of is to rinse them well and put them in a brine of 1/4 cup kosher (Morton’s) salt for every 4 cups of water. Let them brine in this until the bitterness goes away — which could take a few months.
Please tell me I haven’t ruined 17 pounds of olives. I’ve followed your directions to a letter and am half way thru my fifth day of the water soak. I’ve changed the water three time in every 24 hours. First my olives turned very dark olive-drab, even tho submerged, and not they are starting to get a kind of “milky” look to them, and they still have substantial bitterness, although less so than after the first two days. Is all this normal? I’d hate to think ill have to trash them.
Hi Hank, thanks for the thorough info on this type of brinning – I just got a couple of pounds of beautiful, fresh green olives and was going to research how to ‘prepare’ them – found your site.
One word of caution – you do emphasize that dry lye would burn, I would also mention right there the ‘antidote’ in case of an accident: that is, have an acid on hand, like vinegar, to rinse immediately, – instead of rinsing with water which is worse; this is only my opinion going back to the high school chem class, there might be a better treatment for lye exposure.
Thanks Hank, I am a new comer to this olive stuff, but was given (already picked) a five gallon bucket full of the largest green olive I have ever seen and didn’t want one morsel to go to waste… I am keeping my fingers crossed!! Thanks again
After 5 days of water rinsing, they taste like tasteless olives! Now brining for a week.
Thanks for the how-to info! Now I can go pick those green beauties!! My neighbor in Davis has 3 (or 4?) olive trees with a bumper crops and said she would really like it if I could find people to pick and take them. They are a real mess for people who don’t have the time or inclination to processing them. Maybe you would be interested in helping organize a picking party?
“Delicatessen”, me encantan, ahora ha sido la época de recolección en verde y próximamente comienza la recolección en negro para la producción de aceite.
Gracias por la receta, un saludo desde Jaén.
Hi Hank,
I have a feeling that Eric Skokan would really like that food history uber geek list-serve. Can you tell me a little about it and how to subscribe?
Thanks.
Julia Joun
I used “ROOTO Crystals of Household 100% Lye Drain Opener” found at my local Ace Hardware in Roseville.
Soaked 12 hours, made fresh lye mixture and soaked another 8 hours.
I’m on Day 4 of freshwater soaking and they tasted “soapy” last night.
You may have trouble locating lye in a hardware or grocery store. Lye is apparently used in the production of methamphetamine, so a lot of stores have pulled it from their shelves (I know this from trying to locate a local source for loosening the grain on deerhides in the process of braintanning). As Hank noted, there are online sources (soap making websites are a good place to start).
Which parks in our fair “City of Trees” have abundant olives for the taking?
Lye is also used in soap making, and so can often be found online on sites that sell soap making supplies (I’m a soap maker). Roebic lye (100% lye) can be found in 2 lb containers at Lowes in the pluming aisle (the only lye I’ve been able to find at a hardware store in Colorado or Washington). Because lye is also used in meth production, you will sometimes need to show ID when you buy it and sign a form. I had an olive tree in Arizona, and never did a thing with them. Now I live in a climate where they don’t grow, and am kicking myself. Great info.
While Barnes & Noble asks about $300 for this, I suggest an inter-library loan, if you are not all that flush. Or maybe suggest it as a Christmas present to someone who is crazy for your cooking.
Table Olives: Production and processing
A. Garrido Fernandez, M.R. Adams, M.J. Fernandez-Diez
https://books.google.com/books?id=uu51QbtMYLkC
covers the fermentation aspects nicely. And just about everything else. I love me some black cured and fermented olives.
I have found that if you want to hold the olives for a very long time, you can make a much stronger brine. The only downside to that is the olives must be soaked for a few hours to remove the excess salt before you can eat them. I cure mine pretty early to avoid soft olives and those pesky fly invasions.
Peter: I have no idea. Never eaten them.
Scott: No, you leave them whole.
Jared: Yep, use green ones. NEVER lye cure black olives because the process softens the olive. Black olives are already soft, so if you do this with them the olives will turn to mush.
As for your second question, it’s not an exact science, but between 1-4 pounds.
Dustin: I’ve held them in the fridge for a year and they were fine. They will go bad far faster at room temperature — I had some get nasty and mushy after only 3 months at room temperature.
Great site and wonderful recipes! My wife and I have enjoyed many wonderful meals so thank you. I was wondering after the curing process what is the shelf life of these olives?
Hi Hank,
I’ve done the brine cure before, but would like to try this method.
Two questions:
1) Is this method for olives that you are picking in the late summer/early fall (still green), or for late winter olives (ripened up a bit)?
2) For the recipe above (1 gallon of water, 3 Tbs of lye) roughly how many pounds of olives will that cure?
Love your site!
Thanks!
I remember doing this once, though not nearly as precise. I used an old, plastic trash can to cure a zillion olives. I think I used an entire can of Drano. I didn’t protect them from exposure to oxygen. As a matter of fact, I kept the operation the back porch. No wonder my green olives turned black. I would later salt cure my creation in old, one-gallon plastic jugs that once held a milk or orange juice product (finances were a tad tight in those days). Believe it or not, the finished product was REALLY good. I munched on those olives for months. It was a nice, free snack for a starving college student…
Hi Hank. Great info. I read your water cure (have a batch going now) and contemplating the speed (and adventure) of the drain cleaner route.
Question – do you still need to “crack” (slice) the green olives when using lye?
I assume not, as no mention above. Just checking
Thanks.
Is this the process used in making the Gerber green ripe olives, Hank?
Also, acorns aret sarting to fall but it does notlook like a big year so far.