Sweet as a nut – almond orchard waste solutions

With the climate crisis raging, food waste is an ongoing problem. Farmers around the world are already finding it increasingly difficult to produce enough food to feed the world. By 2050, the situation might be untenable.

In the US, almost 40% of all food produced gets wasted. This is an alarming statistic considering the carbon emitted, and the resources and energy consumed during the growing of the crops and in distributing and refrigerating this food. It’s a similar story in all corners of the globe, with food ending up in landfill after it is lost on the farm, during transport, in the retail phase, or in people’s homes.

Almonds seem to be an exception to food waste norms, at least in some parts of the supply chain. The popular nut has a two-year shelf life, so less than 1% of almonds are thrown into the bin at home in the US, less than for any other food item. And because of this, they are perfectly okay to travel by cargo ship, which is a 50 times less carbon intensive method of transporting goods to market.

However, as for many farms, there is plenty of scope for wastage at almond orchards. The nut is grown inside a hull and shell, both of which are harvested to access the almond inside. This is why almond growers in California, the world’s biggest almond-producing region, have worked hard to find a second life for hulls and shells. 

Today, over 3.6bn pounds (1.6bn kg) of almond hulls head into the Californian dairy sector as feed for cows, a move that has a multitude of sustainability benefits. The hulls can replace alfalfa hay in up to 20% of dairy feed formulations, which saves farmers having to grow alfalfa or other crops to make up their cow feed needs. 

Meanwhile, lower-value shells are mulched up and used for livestock bedding, among other things. 

But the almond industry, supported by California almond farmers, has not stopped innovating in the drive for zero waste.

Almond trees have a lifespan of around 25 years. After that, they become unproductive and need to be replaced. But what to do with the trees once they reach the end of their lives? Well, traditionally the trees would be ground up and sent to cogeneration facilities where the wood biomass was burned to generate electricity. But as more renewable energy systems, such as wind and solar, have come on stream, and California’s cogeneration plants have been deprioritised, the state’s almond farmers have looked for alternative options.

The solution that, so far, around 50% of them have turned to is Whole Orchard Recycling. This is a process, pioneered in almonds, that involves grinding the old trees into chips, spreading the chips across the soil surface and then blending them into the soil before replanting takes place. It is a concept that was introduced in 2017, and was adopted with confidence following research carried out by the University of California Cooperative Extension (UCCE) and funded by the Almond Board of California (ABC) and the California Department of Food and Agriculture. 

According to Danielle Veenstra, third generation almond farmer and senior manager for global stewardship and impact for ABC, Whole Orchard Recycling is “one of the biggest things that I know of in agriculture that you can do to capture and store carbon. Essentially, the carbon that’s been captured and stored for the last 25 years is locked down into the soil.” It is a technique that offers many proven benefits for farmers, including increasing organic matter in the soil, improving the land’s water-holding capacity and boosting cumulative yields in the years to come.

More recently, ABC has explored the possibilities of using almond waste for food upcycling. Working with food and drink technology house, Mattson, which specialises in developing new flavours, ingredients and products, almond farmers could soon find exciting new markets for almond hulls. The truth is, hulls are actually “too good” to simply head to animal feed. They are “full of fibre, high in antioxidants and have a unique flavour profile, with floral notes”, according to Veenstra. 

Mattson’s research revealed a number of ways that almond hulls could technically be used in food, arriving at a “top 5” that they tried and tested under laboratory conditions. These were: bread, nutrition bars (similar to a Clif Bar), hops replacement for beer, a coffee extender (allowing for the use of fewer coffee beans, reducing the impact of coffee), and tea (created by roasting the hulls and brewing them to create a black, caffeine-free beverage).

“The exciting thing is that making some of these things – and upcycling food – using almond hulls can deliver massive amounts of fibre that we need in our diets, as well as antioxidants and lower calories,” Veenstra says.

The innovation will need to meet US FDA requirements to prove the nutrition and allergen profile, among other things, before food companies can start sourcing and using this waste material to develop new products. But, according to ABC, that may not be too far away. It will mean food companies can save on the resources and impact created by growing something else.

It could also help to create new revenue streams for under-pressure farmers. Right now, farmers get nothing for their waste hulls. “Should this become a desirable food ingredient, the paradigm might shift,” adds Veenstra. 

The climate crisis exacerbates the challenge of food waste, underscoring the urgency for sustainable solutions within agriculture. The Californian almond industry’s innovative strategies show the potential for reducing waste and enhancing environmental sustainability. By transforming agricultural by-products into valuable resources and exploring new markets for food upcycling, the almond industry is setting a precedent for other sectors.