Chemistry, Materials & Packaging
Beer, Plastic, Insect Feed:
Almonds Find Unexpected Uses in Journey to Zero Waste

The almond industry is growing while also fending off risks — such as declining bee populations — so, it would make sense to strive for its environmental sustainability. Such has been a focus for the Almond Board of California (ABC), which supports thousands of California growers and processors, many of whom are third- and fourth-generation farmers.

We caught up Danielle Veenstra, Manager of Sustainability Communications at ABC — and also a family almond farmer — to find out more about the future of almonds.

The California almond community announced 2025 sustainability goals in January of this year. What are the goals and what led to their development?

Danielle Veenstra: In addition to producing a healthy food that people love, our community is dedicated to growing almonds in better, safer and healthier ways, protecting our communities and environment. Recognizing our leadership role in California agriculture and global almond production, the Almond Orchard 2025 Goals build on decades of previous achievements with targets across zero waste, water efficiency, pest management and air quality. Progress toward these goals are underway, centered in research partnerships and on-farm optimizations.

Our goal is to achieve zero waste in our orchards by putting everything we grow to optimal use. In the case of almonds, that means things like hulls, shells and even the trees at the end of their productive lives.

The zero-waste goal has produced some unexpected ideas. What are some of the most innovative uses for shells and hulls that are being explored?

DV: Many people don’t realize that almonds grow in a shell, protected by a hull, on a tree. These products have traditionally been used for livestock bedding, dairy feed and electricity generation. Originally identified decades ago through the ABC’s longstanding research program, these uses have served us well, but changing markets and other factors have led us to reinvigorate this work and explore new ideas. Led by ABC’s Biomass Workgroup, we’ve invested in eight new research projects this year alone. The aim is to identify optimal uses that have higher value, both economically and environmentally. Early promising leads are in the areas of strengthening recycled plastics, creating fuel, brewing beer and more.

What happens to shells and hulls if alternative uses aren’t deployed? 

DV: In addition to the 2.3 billion pounds of almonds grown in California orchards in 2017, we also produced 1.6 billion pounds of shells and 4.5 billion pounds of hulls. Demand for these hulls and shells has dropped in recent years, following shifts in the California dairy industry. In addition, our production continues to increase as new, young orchards come into production, so not only will we have more almonds, but also more hulls and shells. At this point, we are still able to put these things to use, but we are also preparing for our future. Furthermore, we want to find more diverse and optimized uses that have economic value for the farmer and bring environmental benefits to the world around us.

Let’s talk about economics. From the perspective of a family farmer, how much do some of the new uses for shells and hulls stand to improve the overall profitability of an almond farm? And the almond industry?

DV: Right now, any profit from selling almond coproducts for traditional uses is built into the operating costs of removing the hulls and shells, so the farmer is not getting any economic benefit. However, with this research underway, one major objective is to identify higher-value uses. That’s why ABC is exploring a wide variety of potential uses and considering not just their economics, but also the potential for scalability and commercialization. Given where we are with the research, we can’t quantify those things yet. However, the ultimate goal is that these materials could become valuable products in their own right. In that way, the almond community can fully engage in a circular economy where every coproduct is an input for another valuable product.

What partnerships are proving critical to achieving the sustainability goals?

DV: Partnerships are essential to ABC’s research program and span across understanding almonds’ impact on human health, ensuring food quality and safety, and improving farming practices. In the area of sustainability, we partner with several organizations that help us explore new technologies and out-of-the-box solutions that address farming needs today, while helping to build the almond orchard of the future. To support on-farm improvements, ABC translates research findings into actionable and field-ready recommendations that we share directly with farmers and processors.

In the area of coproducts, an important partnership is with University of California, Davis researchers. One ongoing project is testing whether almond hulls, which are sugary and fibrous, can be used in the emerging world of insect farming. This research project is exploring raising black soldier fly larvae, an important feedstock for poultry and aquaculture, on almond hulls. Another UC Davis project is conducting research trials to determine if almond hulls and shells can be used as part of an alternative, all-natural method to prepare soil before replanting an orchard. If untreated, pests in the soil can feed on the newly planted trees’ roots, stunting their growth and their ability to take up water and nutrients. This method — known as biosolarization — uses hulls, shells, water, tarps and the power of the sun to naturally deplete the soil of oxygen, making it inhospitable to key soil pests.

What new almond-infused products should we expect to see on the market first?

DV: It’s hard to forecast that right now, given the number of projects underway and many variables between the lab and commercialization, but I’ll share a few that I think are particularly exciting.

One promising approach is using almond shells to strengthen post-consumer recycled plastic. Through a process called torrefaction, almond shells can be transformed into a charcoal-like black powder which, when added to recycled plastics, makes them stronger and more heat-stable. The material could also be used to turn tires black, replacing the petroleum-based product that the tire industry currently uses.

Another that I’d really like to see work is extracting the sugar from almond hulls and using it to ferment beverages like beer, hard cider and kombucha. Once the sugar is extracted, you’re left with a fibrous material that can be used as a growing medium for mushrooms. Initial research results look promising; and this could replace traditional peat moss, typically imported from other countries and a limited resource.