Last summer, I spotted a tree on my way home from work sporting pale green balls on its branches. I picked one and asked a landscape architect friend; he identified the ball as an immature walnut. The tree was likely a California black walnut, Juglans californica. (Incidentally, "Juglans" is derived from "Jupiter's balls", as in, the god's manly parts.) Many months later, I came across a recipe for preserved walnuts, which called for immature, green walnuts. Although the recommended variety for this recipe is a black walnut, Juglans nigra, or an English walnut, Juglans regia, all varieties of walnuts are edible. In fact, Native Americans ate California black walnuts as part of their normal diet. But they offer a very poor meat yield per nut compared to other varieties, and it's difficult to obtain, so it's no surprise they fell out of favor. But since the whole fruit is used for this recipe and not just the meat, I figured they would work okay. It would be fun trying, anyway.
Green walnuts are available beginning in June. Obviously you want as large of a fruit as possible in order to maximize your efforts, but you have to pick them before the shell starts to form under the fleshy outer part. If you can push a pin through the nut easily, they're still green enough to use.
|Green, immature walnuts, about the size of a small plum.|
Green walnuts are bitter, so they need to be soaked and/or boiled to remove the bitter taste. One recipe called for soaking for 9 days, changing the water frequently. I opted for boiling them several times in fresh changes of water, since I was making only a small batch.
|After boiling. The peeled nuts start to oxidize quickly, |
turning a dark green/black, hence their name.
Eventually the nuts are boiled in a spiced sugar syrup, then stored for several weeks to flavor.
|Spiced with cinnamon sticks and cardamom seeds.|
There is an art to making syrup, and the instructions are vague, so I had a crystallization problem. I managed to correct most of it, but still ended up with some heavy sugar crystals in the bottom of the jar. There were also some hard crunchy parts in the walnuts -- I'm not sure if those were also sugar crystals, or parts of shell that were forming early. They broke up on chewing, so I ate them anyway!
Conclusion: This was a fun experiment! The walnuts are delicious, but taste of the spices rather than any distinct nut flavor. They shrunk considerably while seasoning -- I'm not sure what happened there. They're excellent with a salty cotija cheese (as in the top photo), or would also be good mixed into plain yogurt. The syrup could be used endlessly -- on pancakes, in drinks, drizzled on ice cream...
Recipes: I mostly followed the directions in this recipe from About Greek Food, but I used a lot of the overall information from this site by "livelonger" on Hub Pages.