The Urban Acorn Forager

By Christine Kosirog


I’m a kitchen herbalist. I make food and medicine for myself and my family from the plants that grow outside my front door. I know the plants around me well from the time I’ve spent searching for, studying and harvesting them. I know which plants prefer which part of my garden, where wild nettles grow in my neighborhood, and where the city has planted St. John’s Wort downtown. A few years ago it occurred to me that in all the time I’ve spent learning from the plants, I was always looking to the ground. That meant I was missing out on so much. So, I made the decision to look UP and was greeted by the trees.

Trees have traveled alongside humans since the beginning of time. We depend on them for everything from shelter to paper, from dyes for cosmetics and bubble gum to landscaping centerpieces, yet we take them for granted. They have a strong, quiet, gentle presence that gets lost in our immediate, screen-obsessed culture. But they are here and they graciously offer their food and medicine. One of the most accessible of these is the acorn that falls from the mighty oak tree.

Harvesting acorns is a simple, satisfying, time-intensive act. It also feels familiar. Ancient. And for very good reason as harvesting acorns has been done in cultures across the world for forever. The first year I harvested, my kids and I took pillow cases around the neighborhood and filled them to the brim while squirrels yelled at us from the tree tops and threw acorns at our heads (which endlessly amused my then 7-year-old). We took our harvest home and spent the next few days bumbling our way through the shelling and processing. We made mistakes. We took deep breaths. We giggled, thinking about all the angry squirrels in East Lawrence. We tasted. We trusted our guts. It was good. I encourage you to do the same. Here’s what you need to know:


-Choose intact acorns that have fallen from the tree and are free of holes or squirrel bites.

-We have a variety of oaks in our area and all are edible (check out for more info). Stick with the ones that have bigger acorns (bur oaks, for example) as they will yield more meat.

-If making acorn flour, think 2:1. If you harvest 2 gallons of acorn, it will yield 1 gallon of flour.

-Worried about the pesky oak mites that are so mighty this year? You can harvest acorns though February, so wait until after a hard frost (warning, my need for acorns is stronger than my aversion of oak mites so if you do wait you run the risk of me and the squirrels taking all the good ones).


Processing acorns is a multi-step process that includes shelling, leaching, and dehydrating. The process requires some time and effort. None of the steps are hard, but you will need to plan ahead and dedicate a few hours. If you are unable to process right away, stick them in a 250 degree oven for 30 minutes to kill off any bugs or mold that would risk ruining your harvest.


-Equipment needed: a comfy spot with a good firm surface, your collection of acorns, a pot of water and a hammer.

-With a firm whack (or two or three) separate the meat from the shells and the thin skin that covers them (fingernails do a good job with this, remove as much as possible but don’t let it make you crazy if you don’t get it all). Place the acorn meat in the pot of water to cut down on oxidation that will occur.

-Acorn meat out of the shell is a creamy, tan, uniform color. Toss aside any that look buggy or otherwise discolored. Some of your acorns may turn to a yellowish-brown color as they sit and wait, that’s ok.



Acorns are nutritious and have been collected by a variety of cultures to supplement diets. They include carbohydrates, fat, fiber and protein. But, they also have a high amount of tannins leaving them bitter and inedible raw. In order to take them from mouth-puckering to mouth-watering you have to remove the tannins through a leaching process. There are two ways go about this, hot or cold, with pros and cons to each. Regardless which leaching process you choose, take a bite of the raw acorn and then taste again through every step. When fully leached the acorn will taste bland (if you wonder to yourself “Why bother?” then you are doing it exactly right!):

-Hot Leaching Process: Place your acorns in a stock pot, cover with water and bring to a boil for 5-10 minutes. Toss out the water, replace with fresh and repeat 5-6 times. This process is relatively quick but you lose some of the nutritional value of the acorn due to the cooking.

-Cold Leaching Process: Place the acorns in cold water and leave in the fridge. Replace with fresh water every day, until the acorns don’t taste bitter any more. From my experience this can take up to 2 weeks. This process is longer, but allows you to keep more of the acorn’s flavor and nutritional value since no heat has been applied.

Dehydrating and long-term storage:

Once your acorns have been leached you need to dry them in order to keep them stable for long-term storage and use. There are two preparations I use for this, dividing my harvest in half and using both techniques.

-Roasted acorns: Roast the leached acorn meat in a 250 degree oven for 2 hours or until they turn dark brown and your kitchen smells amazing! Give them a good stir occasionally through the roasting. Store the roasted acorns in an airtight container in a cool, dark place. If properly roasted they will last as long as any nut.

-Acorn Flour: In batches, place the leached acorn meat into a food processor and grind until you have a rough breadcrumb-like consistency. From there, there are 3 options for dehydrating the meat:

-Place on cookie sheets and put in an oven set at 175 degrees. This will likely take a few days of drying for a few hours at a time.

-Use a dehydrator and follow the recommended time and heat level for nuts provided in the instruction manual.

-Place outside to dry in the sun. Be sure to keep your harvest protected from water, insects and creatures as this will take a few days as well.

Regardless of which option you choose, your end product should feel hard and not stick together when pinched. You will likely need to help the process along by running your hands through it and breaking apart any small bunches that form. Once fully dried, use a coffee grinder to break the “breadcrumbs” into an even, fine “flour” consistency (I have a grinder dedicated solely to the use of herbal preparations so it doesn’t turn everything coffee flavored). Store in an airtight container, just as you would any flour. If properly dried, it will keep for years.




The first year I processed acorns I had the mystery of the acorn to keep me motivated through the long process of preparing them. I had never tasted an acorn and had no idea what to expect. Now I have my personal experience to keep me going. And now I wait ALL year for acorn harvest. Acorns taste, well, nutty. But they also taste earthy and dark and bring a depth and complexity to whatever you cook.

Despite your acorns tasting bland throughout the processing, when you start cooking with them you will realize their power is subtle but strong. Once your acorns are fully dried the culinary possibilities are endless, here’s some of my favorite recipes.

Acorn infused butter. My absolute FAVORITE way to use roasted acorns. It is simple to make and so dreamy good. I only made one container last year and, after tasting it, portioned it out to last. As. Long. As. Possible.

-1/2 cup roasted acorns

-2 sticks good quality butter

-Place both in pan and place on stove over medium heat

-Warm until the butter turns frothy, stirring occasionally

-Reduce heat to low and continue to stir occasionally for 20-30 minutes (the more time the more intense the acorn flavor will be in the final product)

-Remove from heat and strain acorns out (keeping them to add to dishes or eat straight out of your hand)

-Place butter in an air tight container and allow to cool. The flavor will intensify as it cools

-Store in the fridge

Treat this as you would any butter (but you will cherish it like something otherworldly). It is especially good paired with things like scones or sweet breads. My personal favorite is cinnamon chip bread from Great Harvest.

-Acorn Chocolate Chip Cookies. So good! Recipe, and further proof that squirrels really get testy when we take their acorns, here-

Don’t have a sweet tooth like me? That’s ok, there’s plenty of savory foods to be made better with acorns. Here’s some inspiration:

I also have a recipe for acorn wine that I haven’t tested out yet. Interested? Email me at Happy harvesting!