Cracking the Code: How In-Shell Nut Processing Is Redefining Food Sustainability

The standard way we process nuts is a bit… well, dusty. Despite all the lofty sustainability goals set by global food companies, nut processing methods haven’t changed much in decades. Here’s the breakdown:

• Huge portions taken out of the food supply: Up to 20–30% of each nut never ends up in food products. For almonds, that’s the hard outer shell and often some of the brown skin and pulp. For peanuts, it’s the papery hulls. For cashews and walnuts, thick shells are discarded. All that typically goes to low-value uses or straight to waste.

• Lost nutrition: Those cast-off shells and pulps are rich in fiber, minerals, and even protein, yet in conventional processing they’re treated like garbage. That means we’re literally throwing away nutrients that could have enriched our foods.

• Extra water and energy: Think about it: we use water and energy to grow every part of a nut, then spend more water and energy to remove and dispose of the very parts we just grew. Separating kernels from shells, blanching almonds to remove skins, pressing nuts for oil then dealing with the leftover cake… it’s a resource-intensive breakup process.

• Embodied resources underutilised: When you discard 30% of a nut, you also discard 30% of the farm water, land, fertilizer, and carbon emissions that went into growing that nut. All the upstream resources embodied in those shells and skins are essentially wasted.

For sustainability professionals, this is a classic inefficiency lurking in the supply chain. It’s like a leak in your production pipeline that quietly inflates your product’s water and carbon footprint. In an era of net-zero targets and water stewardship pledges, such inefficiency is a big nut to crack.

This is where in-shell processing comes to the rescue – basically, a circularity upgrade for the nut industry. RE-NUT’s patented in-shell technology flips the script on traditional methods. Instead of shelling almonds, cashews, peanuts or hazelnuts and tossing out the hulls and fiber, our tech processes the whole nut as one unit.

What does that look like? In practical terms, we wet-mill the whole nut (shell and all) into a smooth slurry and then separate that into different streams to create multiple high-value products. The result:

• Dramatically lower CO₂ emissions: A third-party life cycle assessment found that almond milk made with in-shell processing cuts GHG emissions by 15–53% per liter compared to the conventional almond milk process. Similarly, the almond flour produced as a co-product has about 18–35% lower carbon intensity than standard almond flour. By incorporating the shell’s mass into the edible product, we’re essentially getting more food output from the same farming footprint – which means less carbon per unit of food.

• Big water savings: Because more of each nut ends up in the final product, fewer nuts (and less irrigation) are needed for the same amount of milk or flour. Our LCA shows the water-scarcity footprint of RE-NUT almond milk is ~20% lower than the industry standard per liter, and the almond flour’s water footprint is about 25% lower than conventional. In plain English: every time you choose in-shell processed almond products, you save thousands of gallons of water at the farm. That’s huge for water-stressed regions like California’s Central Valley.

• Higher yield, less waste: We turn what used to be waste (shells, skins, pulp) into edible output. Each kilogram of raw nuts produces significantly more food product than it would via old-school processing. It’s a zero-waste, eat-the-whole-nut approach. Instead of a pile of shells going to a landfill or to low-grade livestock feed, those fibers and nutrients become part of a nutritious flour, a creamy nut milk, or even a healthy oil.

• Streamlined supply chain: In-shell processing isn’t just good for the planet – it’s efficient for producers. By eliminating steps like separate shelling operations, waste hauling, and secondary processing of byproducts, manufacturers can save on labor, energy, and transportation. Fewer trucks hauling away bulky shell waste, fewer facilities needed to handle different fractions of the nut, and an overall leaner production line add up to lower operational emissions as well.

In short, we’re not making sustainability vague, we’re making it measurable. By designing waste out of the process, we deliver tangible carbon and water reductions that you can plug straight into your ESG reports.

And guess what? Using the whole nut doesn’t mean a worse product. There’s zero compromise on quality. In fact, our trials show that consumers prefer the creamier, richer texture of the plant-based milks produced this way (all that extra natural fiber gives a lovely body to the milk). It’s a rare win-win-win: better for the planet, better for people, and better for product quality.

While almonds have become the poster child for nut sustainability debates, they’re only part of the story. Our in-shell processing approach can work for all major tree nuts and even groundnuts (peanuts). Each of these has its own sustainability quirks and opportunities:

• Peanuts: When peanuts are processed for peanut oil or peanut butter, their paper-thin shells (hulls) are stripped off and mostly discarded. Fun fact: those shells make up about 22% of a peanut’s weight! Research has shown you can upcycle peanut shells into high-fiber food ingredients instead of tossing them out. Why not include that fiber into peanut butter or peanut based products? Our tech can do exactly that, milling peanuts whole so that hull fiber ends up in the final product.

• Hazelnuts: If you enjoy chocolate-hazelnut spreads, you might not know that hazelnuts have a hard, smooth shell. Hazelnut shells are rich in fiber and antioxidants, some food innovators have already started grinding them into flour for baked goods. In-shell processing would let hazelnut product makers incorporate that goodness from the start, creating high-fiber hazelnut milk, hazelnut paste or flour and eliminating the need to manage shell waste.

• Nuts about Walnuts? Walnuts, pistachios, pecans also have significant portions of inedible shells or hulls. Today those often go to low-value uses (mulch, energy co-generation, or landfill). With a whole-nut approach, even these tougher shells can be ground down and integrated as dietary fiber. It’s all about reimagining what’s “inedible” as actually edible (and beneficial) with the right tech. We like to say: if it grew from the soil, we find a way to keep it in the food cycle.

The big picture here is a shift to circular thinking in nut production. Rather than a linear model (grow nut → remove shell → discard shell), we go circular (grow nut → use all of nut → no waste). This not only cuts waste and emissions, it also boosts nutrition by retaining more fiber and micronutrients from the whole plant. It’s the kind of holistic innovation that checks all the boxes: climate, water, waste, nutrition, you name it.

Let’s get real, if you’re a sustainability lead or product developer at a food company, you’ve likely heard some pushback like: “Sounds eco-friendly and all, but what’s the ROI?” or “We already have a sustainability plan, why change our ingredients?” We hear you. So let’s talk business. Adopting in-shell processed ingredients isn’t just an environmental decision, it’s a strategic financial move. Here’s why:

• More product per input = Better margins. When you use the whole nut, you simply get more sellable product out of each ton of raw material. Higher yield translates to more revenue. Instead of, say, 70% of an almond turning into milk and flour and 30% becoming waste, you’re utilizing 100%. That means every dollar spent on almonds yields more dollars in finished goods. Efficiency is profit.

• Lower footprint = Market advantage. Consumers and retailers are pressuring brands for lower-carbon, lower-water products. If you can slash the footprint of your almond milk or nut butter by double digits (as our data shows), that’s a huge differentiator. It can help you meet science-based climate targets, water reduction goals and win market share. Think of it as future-proofing your supply chain against ESG scrutiny. Sustainability is no longer a feel-good story.

• Upcycled ingredients = Cleaner labels. Using what used to be “waste” fiber and nutrients directly in food taps into the incycling trend. You can literally label it as such: “made with whole almonds”, which consumers increasingly love to see. It’s clean-label, it’s novel, and it tells a great story about zero waste. All that can command a premium and stronger brand loyalty.

• Streamlined process = Operational savings. Traditional nut processing has multiple stages (shelling, separating, press cake handling, etc.) and each stage adds labor, equipment, and energy costs. By consolidating steps and eliminating waste streams, companies can save on transportation and storage (no more trucking out shells or storing hulls), and potentially on energy too. Fewer process steps also mean fewer points of failure and quality loss. In other words, you simplify your production and your logistics, simplicity tends to save money.

So, far from sucking your margins, sustainability in this case can actually improve them. It’s not often that doing the right thing for the planet also directly boosts the bottom line and when it happens, smart businesses leap at the opportunity.