Food Upcycling: Gnocchi Made from Brewery Spent Grain

What once disappeared into cattle and pig feed troughs is now appearing in chilled cabinets alongside organic pesto and speciality cheeses: gnocchi made with flour from brewery leftovers. Two young founders demonstrate how supposed waste can become a marketable product with added value, entering the debate on wasted resources, climate protection and rising food prices.

What is really behind these “waste gnocchi”

The concept behind them is called food upcycling. It means giving a by-product a second life, not simply as a cheap input but as a new, higher-value product. The fashion industry has long used this approach: discarded sails become rucksacks, while old bicycle tyres are turned into belts. In food, however, it remains far less common.

That is exactly where these new gnocchi, currently sold by a French organic supermarket chain, come in. The innovation is based on a brewing by-product 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 making their way onto people’s plates.

An overlooked brewing by-product becomes a food ingredient in its own right, offering flavour and nutritional value.

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

Beer brewing relies on cereals, most commonly barley. During mashing and lautering, starches and flavour compounds are extracted from the grain. What remains is spent grain: damp husks and fibrous cereal material. In practical terms, it is comparable to the orange pulp left after oranges have been pressed for juice.

Spent grain has traditionally been used mainly as feed. Breweries sell it to farmers at low cost. While this is not a pointless cycle, it does not make full use of its nutritional potential. Spent grain contains:

• high levels of fibre
• a significant proportion of plant protein
• residual minerals and plant compounds

Those qualities make it suitable 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 that step, developing a process that converts spent grain into a stable flour. They add around twelve per cent of this flour to a traditional gnocchi dough. The other ingredients resemble those in the familiar Italian potato product: potatoes, a little wheat flour, salt and spices.

Although the spent-grain share may initially seem small, it noticeably changes the product:

• Flavour: The gnocchi develop a gently roasted, nutty character; testers describe them as “toasty”.
• Texture: They have a slightly more robust bite without becoming rubbery.
• Nutritional value: Fibre and protein from the spent grain increase their nutritional value compared with conventional gnocchi.

The product is sold through an organic supermarket chain for around €3.40 per pack. This places the gnocchi at the higher end of the market without making them excessively expensive: 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 spent grain accounts for “only” twelve 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 added, the dough is more likely to tear, hold its shape less well and break apart more easily during cooking.

The producers therefore had to determine the point at which the sustainability concept could still deliver a practical everyday texture. Twelve per cent is a compromise: sufficient to credibly alter the nutritional profile and the product story, but not so much that the gnocchi become little more than an experiment.

Why food upcycling is gaining momentum now

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

Every ingredient given a second life reduces pressure on land, water reserves and the climate - and, ideally, costs as well.

Spent grain is a prime example of unused potential. It is produced in large, concentrated quantities, particularly at bigger breweries. Its supply is relatively predictable, it is hygienically consistent and easy to collect, creating ideal conditions for industrial processing.

For breweries, this can open up an additional source of income. Rather than giving spent grain to farmers for virtually nothing, they can work with food manufacturers and benefit from sales of the refined product. At the same time, the sector can present itself as part of the climate solution rather than only part of the problem.

How safe and worthwhile is it for consumers?

Many consumers may ask whether it is genuinely appetising, or whether “leftovers” are simply being put into food to cut costs. From a technical perspective, several factors clearly support the concept:

• 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 further requirements covering drying, storage and processing.
• Its high fibre content may have positive effects on digestion and satiety.

At the same time, its use should be clearly labelled. People with gluten intolerance or allergies to particular cereals need to be able to identify products containing spent grain easily. Transparency builds trust; without it, upcycling can quickly remain a niche topic 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 appear first: in settings where customers are prepared to try something new and pay a modest premium. Over the medium term, though, the approach could become much more widespread.

Supermarket chains are constantly seeking stories for their own-label products, whether “regional”, “high-protein” or “more climate-friendly”. Gnocchi made from brewery by-products bring together several of these promises. Restaurants have similarly interesting opportunities: a brewpub serving beer and complementary side dishes made from the same raw materials can create a credible sustainability profile.

Other ingredients suited to food upcycling

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

• Coffee grounds as a growing medium for mushrooms or for extracting flavours.
• Orange peel for marmalades, snacks or flavourings.
• Rice bran, produced during rice polishing, as a fibre source in baked goods.
• Potato peel as crispy chips in hospitality.

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 farming. Potatoes, cereals, fruit and vegetables will remain the foundation of diets. The interesting question is how far by-products will move into everyday eating in future. If pasta, bread, snacks and drinks increasingly contain “second-life ingredients”, perceptions of what is normal will change.

Manufacturers must also assess the limits carefully. Not every remainder 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
• its technical processability
• sensory qualities, including flavour, aroma and texture
• consumer acceptance and willingness to pay

These spent-grain-flour gnocchi offer a tangible example of how this balancing act can work. The product tells a clear story, provides a practical added benefit and remains close enough to familiar flavours to work in everyday meals.

Choosing products like these consciously 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 discarded without a second thought.