Pennycress Seed Harvest

Pennycress seeds have a spicy, somewhat peppery taste. They make an excellent spice and I have used them in soups, stir fries, eggs, home fries, potato salad, and on fish, although there are certain to be many more uses. I enjoy nibbling on the seeds too, as I can taste the fruits of our labors--although Gregg can tell from my breath every time (even if he is on the other side of the room) when I have been eating pennycress seeds.  

To harvest the seeds, Gregg and I like to hold the dry pennycress plant by its base (so as not to pull it up) and then use the other hand to strip a stalk of its seeds and pods. We make an effort to leave rows of seeds and pods on each plant, spacing out our foraging within the pennycress patches so as to allow for regeneration. The drier the plant, the better, as it is easier to separate the seeds from seedpods.

We have invented our own method for threshing (loosening the grain from the chaff) and winnowing (separating the chaff from the seed; often by throwing the mixture into the air and letting the wind carry off the chaff while the heavier seed falls to the ground). Certainly there are better methods, but as we are a small scale operation, the following works for us: 

1. Take the container of seedpods into the house and let them dry out even more for a day or two. 
2. Use one's hands to break up the seedpods, a method that separates most but not all of the seeds from the chaff. Then shake the container a bit, causing most of the seeds to gather at the bottom.
3. Scoop up the seeds and lay them in one end of a baking sheet. Tilt the baking sheet and tap lightly on its underside, causing the round seeds to roll to one end. It is necessary to occasionally move the chaff/seed mixture back up to the top of the pan in the process, but the seeds that do break free begin to pile up, cleaned of chaff, at the bottom of the pan. (I have to credit Gregg for this method.) 
4. This technique is not 100%, so you are bound to have leftover seeds in your crop--in which case, sprinkle the leftover chaff and seeds outside where you want pennycress to grow!

Pennycress is a hardy weed that grows in waste ground and fields, according to Peterson. Cattail Bob states that pennycress is common up to 9,000 feet, although we have it here at the house above 11,000 feet--probably because we had some soil trucked in that already contained the seeds. 

Pennycress is also proving to be an important plant in the biofuel movement, particularly in Illinois. According to an Peoria Journal Star article by Steve Tarter, ''Wonderfuel' crop harvested in Mapleton, pennycress seeds "contain 36 percent oil - twice as much as soybeans. That much oil makes pennycress the perfect crop to blend with diesel fuel to make biodiesel, said officials of Biofuels Manufacturers of Illinois, LLC." You can also check out www.prodigalsun.org for information on pennycress' potential as a biofuel feedstock that doesn't hamper food production for humans.

I am also curious about the nutritional value of pennycress but have not yet been able to find any information about it. In the meantime, Gregg and I will continue to enjoy the flavor, the convenience, and the novelty of pennycress, a wild edible plant that grows fresh right in our front yard.

[UPDATE - 5.11.11: According to the Canada Biodiversity Information Facility, pennycress contains glucosinolates known to poison cattle when consumed in significant quantities, for which reason they classify pennycress as toxic. I spoke with a friend who is studying plant toxicity in veterinary school, and she explained that "significant quantities" refers to something like 2-3 days of nonstop grazing. There is, in fact, a long list of wild edible plants (and some commercial plants) known to be toxic to ruminants when consumed in quantity. The moral of the story for humans is that we shouldn't eat as much of these plants as a cow could eat over the course of 2-3 days. Try to go a little easier on yourself than that.]

Post updated 6.26.10, with link to Prodigal Sun added. Post updated 5.11.11 with clarification to the "UPDATE."