It's green black walnut season. I don't know how people figured out you could use unripe walnuts in cooking, but I'm sure glad they did, and after you try making my fermented green walnut molasses recipe, I think you will be too, even if you don't like the taste of black walnuts cracked from the shell.
Background
Unripe black walnuts are pretty well known in the wild food community, due at least in part to the popularity of Nocino, the Italian black walnut liquor. While it makes a great conversation piece and digestif, I can only have small amounts of alcohol due to complications from Lyme, so I wanted to make something more versatile.
A few years ago I was reading an old book, (I can't remember the name). In the preserves section, like many old books I've read from the1900's (Housekeeping in Old Virginia being a great one) there were a number of preparations calling for green black walnuts. One of them was "Green Walnut Syrup". I made a note of the name in a file and forgot about it for a few years.
While working with Ida Graves Distillery to produce the Nocino we made from 2021-2023 I remembered the green walnut syrup and thought it'd be fun to use it as the sweetener for nocino instead of sugar.
Knowing that unripe walnuts have a high water content, I figured a Korean cheong-style syrup where an ingredient is immersed in sugar for long periods would work well. Now, five years after I originally posted this, I know of more than a few friends around the country selling walnut syrup at farmers markets as a value-added product.
I'd never heard of anyone else talk about green walnut syrup until a charity dinner I did with Hank Shaw this year. After I served a small glass of walnut wine after dinner, a man came up to thank me for reminding him of a memory with his German grandmother.
He said his family would harvest the green nuts and cook them into a thick, black syrup his grandfather ate on buttered toast every day. I'm sure there's more references like this out there, so if you know of any, please leave a comment.
Using different species of walnuts
After making this for a few years now, of course I had to try it with different varieties. Butternuts or white walnuts (Juglans cinerea) are the closest approximation to black walnuts, but ripen a full month earlier and should be harvested in Early to mid-June.
Green black walnuts can be picked up until Mid July where I live. I've heard of others making it from unripe shagbark hickory nuts, but I haven't made it myself yet.
How to Make Walnut Syrup (The Maceration)
First you need to harvest the green walnuts from a tree. Look for trees in full sun with low branches that are easy to reach. Ideally they'll be young and tender enough to cut with a knife without any resistance, but, as you won't be eating the physical nuts, it's ok if they're slightly larger. I like them the size of ping-pong balls.
Variations due to the age of the nuts
Very young nuts can work (see below) but they contain less water than larger nuts.
Nuts that have visible brown shells inside should be avoided as the hulls may start to break down during the process. As long as you can easily cut through the nuts or pierce them with a toothpick, they should be fine. Expect some variation from tree to tree.
Maceration
Take your green walnuts, cut them in half, then mix them with twice their weight in sugar, which could be white, brown, or unrefined cane sugar. You could also use maple syrup or honey.
Pack the nuts and sugar in a glass container like a mason jar so you can watch the show.
After only a day or two, the alchemy begins as the sugar coaxes out what seems an impossible rush of natural water from the green walnuts.
When the water releases, the walnuts will be swimming in liquid and there will be visible fermentation and bubbling, pressurizing the contents of the jar and letting out a satisfying hiss when the lid is opened. This is natural and the fermentation isn't strong enough to worry about jars exploding.
After at least 30 days, you scrape out the black, sugary walnut sludge into a pot, bring it to a boil, then strain, discarding the walnuts, and bottle the syrup. Ah Viola.
While I typically discard the nuts, there's still some goodness you can coax from them if you want. The cooked nuts can be used to make nocino or vin de noix, and will require less aging for the tannins to subside.
Originally I'd hoped to capture the toe-curling aroma of green citrus from the young nuts, but over time the syrup develops the same sort of earthy, rich leather notes of walnut liqueurs. It's not a bad thing.
Aging Out The Tannins
One clarification I wanted to emphasize here is the tannins (bitterness) in the syrup. If you've made walnut liquor you'll know it tastes horribly bitter until the tannins relax. For reasons unknown to me (maybe the age of the nuts?) some walnut syrups I've made have been ready immediately, or only need a few days of aging, but some need a month or more.
Long story short, if your syrup tastes bitter at first don't worry-you didn't do anything wrong. Set the jars on the shelf for a couple weeks and be patient. The timeline is variable, but eventually the tannins will break, revealing a similar, subtle walnut flavor as with walnut liquor.
How to use it
While the flavor is not as intense as mugolio, it's still fun. You can use the walnut syrup anywhere you would use maple syrup, and it loves yogurt and creamy soft cheeses. I've also used it for baking in things like granola, and anywhere I'd use molasses.
Using black walnut molasses to flavor spirits like nocino might be the ultimate version though: a study in the flavor of black walnuts only the forest can provide.
Related Posts
Black Walnut Molasses
Equipment
- 1 Mason jars you'll need two quart jars or one half gallon jar
- 1 Strainer or cheesecloth
- 1 4 quart stainless steel saucepot
Ingredients
- 1 lb (roughly 15-22) young unripe black walnuts or butternuts soft enough that they can be cut through with a knife
- 2 lb Brown sugar or Turbinado sugar or cane sugar
- 2 teaspoons Organic corn syrup to prevent crystallization, optional
Instructions
Harvest and Prep the Nuts
- Harvest unripe black walnuts directly from the tree. Younger is best, smaller than a ping pong ball. Older, more round nuts may be more tannic.
- While it may be tempting to harvest walnuts that have already fallen, you will want to cut some of them in half to make sure they're pearly white and clean on the inside, without any spotting or deterioration. Wash the walnuts and reserve.
- Wearing gloves, cut the walnuts in half using a heavy knife on a cutting board that won't stain. Older recipes often mention crushing or pounding the unripe nuts, which you could also do, but beware of splattering juice.
- Mix the walnut with the sugar, then pack into a container that can accomodate the entire mixture. For the amount listed, you would want a half gallon mason jar.
Maceration
- Allow the walnut-sugar mixture to sit at room temperature or outside for at least 30 days, and up to a few months, opening the jar occasionally to release carbon dioxide as the mixture will ferment. Shake or stir it occasionally to coat the nuts in the fermenting syrup and help prevent mold. Set a reminder to cook the jar in 30 days.
Boiling, straining and storing
- After 30 days, scrape the sugary walnut mixture into a non-reactive sauce pot with high sides. Add the corn syrup if using. On high heat, bring the mixture to a simmer to melt the syrup, turn the heat off and remove the walnuts using a slotted spoon and discard.
Finishing and Jarring
- Bring the syrup back to a boil turn off the heat and wait a minute for the foam to settle, skim off the foam if present (it will subside as the jars cool either way). Pour the piping hot syrup into the jars leaving ½ inch of headspace, screw on the lids tightly.
- The cooking process should take about 10 minutes. You're only melting the syrup and getting it hot to sterilize it, not reducing it. Overcooking the syrup will cause the jars to crystalize.
- Process the jars in a water bath, 10 minutes per pint. Some people simply turn the jars upside down and allow to cool and seal. The syrup will last for years and doesn't need to be refrigerated until it's opened. It can be a little tannic at first but mellows as it ages.
Laurice Bankhead
Many thanks, Alan! I managed to gather some green black walnuts at the perfect time this year and decided to try out this recipe. Super easy with a yummy result. I used unrefined dehydrated sugar cane juice (aka panela/sucanat) and let it macerate for over 40 days. I just processed it into jars this morning. I had a couple spoonfuls left over and drizzled it over vanilla ice cream for a special treat. Once again, you did not disappoint!
edris clarke
Allan, your life story is so fascinating. I really impressed on how by God's grace, you pulled through and overcame all the seemingly insurmountable circumstances that laid in your pathway. My daughter and I use to do a lot of foraging and gathering of different kinds of mush. But after she died I was devasted. I love to be in the wild. Must also say, that I was introduced to foraging by an excellent forager, by the name of Wildman Steve Brill. He still leads foraging groups in NY, NJ, Connecticut, and Pennsylvania..I need to put the knowledge that I gathered over the years, but I am not technologically savvy. I miss my dear daughter so much, since she was the computer guru.. I came acoss your site this morning, becase I was looking for a recipe to make black walnut tincture. Talking about that can I use apple cider vinegar instead of vodga?. I dp not deal with alcohlas a christian. Is there grape vinegar? Just what else can I use to make any tincture? I am getting your book. Perseverance did make you conquer, I think by the grace of God, I will too. Have a beautiful day in God's great out of doors.
Alan Bergo
Thanks for your kind words. First I need to say I do not give advice on medicinal aspects of plants or mushrooms as I’m not an expert in that area. You will want to consult an herbalist here.
What I do know is that If you cannot consume alcohol in any way, shape or form, you will be unable to use tinctures as the success hinges on alcohol-soluble compounds that will not be transferred through water or vinegar.
Andrea C.
Hi! I made a couple of jars of these back in 2022, stirred them as directed for a month, then apparently forgot about them on my pantry shelves. I've inspected the jars; there's no mold, the syrup is a dark black and smells licoricey/molassesy like I would expect. Any reason I couldn't continue on with simmering them to finish the syrup? Would you recommend "diluting" it down with more brown sugar since they've infused this long? Thank you!
Alan Bergo
This is fine, proceed.
Elie
Hi- starting this recipe now. Curious if you can use the walnuts for any other purpose at the discard step?
Alan Bergo
Yes use them to make the walnut wine or nocino on this site.
Joseph
Did you end up trying this as the sweetener in nocino? How did that turn out, would you recommend it?
Alan Bergo
Absolutely, it's great.
Catrin
Hi Alan!
I’m really excited to try this recipe but all I have are white walnuts, which are kind of hairy and sticky on the outside. Would this recipe still work with the white ones?
Alan Bergo
Yes as long as they’re tender enough to cut. Remember they ripen a whole month earlier than black walnuts so you need to get them quick.
Catrin
Good to know!! Thank you!
Megan
I made this recipe at the end of last August (2024) and I'm just now processing them. They're a little stinky do you think it's still okay to use them?
Alan Bergo
I need more information here to be able to give you advice. I need you to walk me through exactly what you did.
Teresa
Can I use honey instead of sugar?
Alan Bergo
Absolutely. Honey contains more water so the syrup will be loose, you’ll need to reduce it slightly to get a spoon-coating consistency. Don’t worry about exact proportions, just cover the nuts in honey.