Food Upcycling: Gnocchi made from brewery spent grain

What once disappeared into the feed troughs of cows and pigs is now appearing in the chilled aisle alongside organic pesto and premium cheeses: gnocchi made with flour from brewery by-products. Two young founders demonstrate how supposed waste can become a marketable product with added value, placing them at the heart of the debate on wasted resources, climate protection and rising food prices.

What is really behind the ‘waste gnocchi’

The concept behind it is called ‘upcycling’. It means giving a waste product a second life – not merely as a cheap raw material, but as a new, high-quality product. This has long been familiar in fashion: discarded sails are turned into rucksacks, while old bicycle tyres become belts. In food, however, this approach remains far less widespread.

That is precisely where the new gnocchi, currently sold by a French organic supermarket chain, come in. The innovation is based on a by-product of beer production known as spent grain. Until now, these cereal remnants have mainly been used as animal feed or sent to biogas plants. Now, at least some of them are ending up on people’s plates.

An underestimated by-product of brewing is becoming an independent food ingredient with flavour and nutritional value.

From brewing vessel to frying pan: what exactly is spent grain?

Brewing beer involves cereals, usually barley. During mashing and lautering, starches and flavour compounds are extracted from the grain. What remains is damp husk material and fibre: spent grain. In functional terms, it is similar to the orange pulp left behind after orange juice has been pressed.

Until now, spent grain has primarily been used as animal feed. Breweries sell it cheaply to farmers. This means the cycle is not pointless, but its nutritional potential is not being fully exploited. Spent grain contains:

• high levels of dietary fibre
• a significant proportion of plant protein
• remaining minerals and secondary plant compounds

These qualities make it relevant for human diets, provided it is dried hygienically, milled and incorporated sensibly into recipes.

The founders’ idea: gnocchi with 12 per cent spent-grain flour

Two young entrepreneurs have taken this step, developing a process that turns spent grain into a stable flour. They add this flour at around 12 per cent to a traditional gnocchi dough. The remaining ingredients resemble those in the familiar Italian potato product: potatoes, a little wheat flour, salt and seasonings.

Although the spent-grain proportion may initially sound small, it noticeably changes the product:

• Flavour: The gnocchi gain a lightly roasted, nutty character – testers describe them as “toasty”.
• Texture: Their bite becomes somewhat more substantial without becoming rubbery.
• Nutritional value: The fibre and protein in the spent grain increase the nutritional value compared with conventional gnocchi.

The product is sold through an organic supermarket chain for approximately €3.40 per pack. This places the gnocchi at the higher end of the market, though not at an excessively high price point – a typical ‘conscious consumption’ item combining curiosity with sustainability ambitions.

Why use only a small proportion? Technical limits in the dough

There are several reasons why the spent-grain content is ‘only’ 12 per cent. Spent-grain flour absorbs water differently from wheat flour or potato starch, and it does not contain binding proteins such as gluten. If too much is used, the dough tears more easily, loses its ability to hold its shape and the gnocchi break apart more quickly during cooking.

The manufacturers therefore had to test the point at which the sustainability concept could still work alongside a texture suitable for everyday use. Twelve per cent is a compromise: enough to credibly alter both the nutritional value and the story behind the product, without turning it into a purely experimental food.

Why food upcycling is gaining momentum now

Food waste is an enormous issue: every year, millions of tonnes of edible goods in Europe end up in bins or waste streams. At the same time, agriculture faces growing pressure to use land and resources more efficiently. Upcycling addresses exactly this challenge.

Every raw material given a second life eases pressure on land, water reserves and the climate – and ideally reduces costs too.

Spent grain is a prime example of unused potential. It is produced in large volumes and in a highly concentrated form, particularly at larger breweries. It is relatively predictable, consistent in hygiene terms and easy to collect – ideal conditions for industrial processing.

For breweries, this creates an additional source of income. Rather than practically giving spent grain away to farmers, they can work with food producers and benefit from sales of the refined product. At the same time, the sector can position itself as part of the climate-protection solution rather than simply part of the problem.

How safe and sensible is this for consumers?

Many consumers may ask: is it genuinely edible? Or are ‘leftovers’ simply being put into food to cut costs? From a technical perspective, several factors clearly support the idea:

• Spent grain comes from cereals suitable for food production.
• The raw material is already subject to strict hygiene checks during beer production.
• Its use in food is governed by additional requirements for drying, storage and processing.
• Its high fibre content can have a positive effect on digestion and satiety.

At the same time, its use should be clearly declared. People with gluten intolerance or allergies to certain cereals must be able to identify products containing spent grain without ambiguity. Transparency creates trust – without it, upcycling can quickly remain a niche interest for only a small group of enthusiasts.

What this means for supermarkets and hospitality

Its launch in a specialist organic shop shows where innovations of this kind usually emerge first: in an environment where customers are prepared to try something new and pay a modest premium. Over the medium term, however, the concept could become much more widespread.

Supermarket chains are constantly looking for stories for their own-label products, whether ‘regional’, ‘high-protein’ or ‘more climate-friendly’. Gnocchi made from brewery by-products combine several of these promises. Restaurants have similarly compelling opportunities: a brewpub serving beer alongside matching side dishes made from the same raw materials could build a credible sustainability profile.

Other raw materials suitable for food upcycling

Spent grain is only one example. Food-industry specialists are already discussing numerous other ways to make practical use of side streams from food production. Examples include:

• Coffee grounds as a substrate for growing mushrooms or extracting flavours.
• Orange peel for jams, snacks or flavourings.
• Rice bran, produced when rice is polished, as a source of fibre in baked goods.
• Potato peel as crisp chips in hospitality settings.

Projects such as these show how entire value chains can shift: what was considered a cost yesterday can become the starting point for new business models.

Opportunities and limits for the future of food

Food upcycling will not replace conventional agriculture. Potatoes, cereals, fruit and vegetables will remain the foundation of every diet. The more interesting question is how far by-products will move into everyday food. If pasta, bread, snacks and drinks increasingly contain ‘second-life ingredients’, the idea of what is normal will change.

At the same time, manufacturers must carefully consider where the boundary lies. Not every residue is suitable for the plate; some materials are better suited to biogas production or animal feed. Whether food upcycling makes sense depends on several factors:

• the quality and safety of the by-product
• technical processability
• sensory characteristics, including flavour, aroma and texture
• consumer acceptance and willingness to pay

The current gnocchi made with spent-grain flour offer a tangible example of how this balancing act can succeed. The product tells a clear story, delivers a functional benefit and remains close enough to familiar flavours to work in everyday meals.

Choosing products like these consciously when shopping does more than conserve resources; it also sends a clear signal to retailers and industry: food innovation does not always have to mean becoming ‘more exotic’ – sometimes it is enough to look more closely at what is already there and has previously been carelessly discarded.