Lidl Berliners in the stove: a Polish YouTuber’s provocative heating experiment during the energy crisis

As energy prices across Europe continue to bite, a Polish YouTuber has tested an option that sounds like an internet joke but was carried out with real intent. Instead of heating with wood pellets or wood briquettes, he fed a cast-iron stove with fatty pastries-specifically, supermarket Berliners bought in bulk from a discount chain. What begins as click-worthy absurdity quickly turns into a surprisingly methodical experiment, and a pointed comment on the energy crisis.

133 Berliners from Lidl: why Marek Hoffmann (“AdBuster”) did it

Marek Hoffmann, better known online as “AdBuster”, set out to see whether household heating costs could-at least on paper-be reduced by swapping conventional fuels for something completely different. The spark for the idea came from pre-holiday price promotions ahead of Poland’s traditional Fat Thursday, when sweet, fried treats are especially popular.

He noticed that, in many supermarkets, these pastries are heavily discounted in the run-up to the day. In his local offers, the price per kilogram of fatty pastries fell below the going rate for wood pellets, which are commonly used to heat homes in Poland. That price oddity became the premise of a YouTube video: could a food product ever “make sense” as a fuel when the market gets distorted?

For the test, he bought:

• 133 Berliners from Lidl
• Total weight: 10 kg
  
• Total cost: €2.85
  
• Cost per piece: roughly €0.02
  

At that point, the arithmetic was hard to ignore: the per‑kilogram price was clearly lower than pellets. Hoffmann’s hypothesis was simple-if the pastries burned reasonably well, they might theoretically be cheaper heat, at least during short-lived discount windows.

Using food as fuel may look financially tempting, feels morally uncomfortable-and can be technically more effective than many would expect.

Energy content under scrutiny: fatty pastries edge out wood briquettes

To keep the video from being pure spectacle, Hoffmann leaned on the key metric that actually matters for fuels: energy per kilogram, often shown as a heating value or calorific value. Volume is secondary; what counts is how much usable energy is packed into the material.

Based on the figures used for his comparison, the numbers looked like this:

Fuel	Energy content (per kg)
Fatty pastries (Berliners)	approx. 18.5 MJ
Wood briquettes	approx. 18.27 MJ

On paper, fatty pastries come out fractionally higher than wood briquettes. That result is not mysterious: Berliners contain substantial fat and sugar, both of which release a lot of energy when burned. Chemically, this behaves less like “bread” and more like a blend of oil-rich material and carbohydrates.

Converting MJ to real-world heating: what those numbers imply (extra context)

It can help to translate megajoules into something closer to what households recognise. 1 kWh ≈ 3.6 MJ, so 18.5 MJ/kg is roughly 5.1 kWh/kg. At 10 kg, the batch contained about 51 kWh of energy in total. At €2.85, that is around €0.06 per kWh before you factor in stove efficiency, heat losses, and the practical drawbacks of burning an unsuitable material.

That additional perspective doesn’t make the idea sensible-but it does show why the price signal can look “compelling” in a crisis.

What happened in the cast-iron stove

Hoffmann ran the burn in a heavy cast-iron stove, lighting the pastries much as he would typical solid fuels. The outcome surprised him:

• The stove temperature climbed rapidly to several hundred degrees Celsius.
• The burn continued for almost five hours.
• Melted fat and sugar helped the pastries smoulder and burn steadily rather than going out quickly.

The stove maintained usable heat for an extended period, and the load burned down without constant refuelling. In purely practical terms, the trial “worked” far better than most viewers would assume.

Nearly five hours of heat from €2.85 worth of fatty pastries-financially seductive at first glance, and broadly consistent with the energy maths.

When heating becomes a moral test: is it acceptable to burn edible food?

Even with the technical success, Hoffmann didn’t present the result as a clever hack. The uncomfortable truth is that he did not burn waste; he burned edible food, albeit deeply discounted. In the video, he openly frames it as a moral dilemma.

The central question is blunt: is it defensible to heat a home by burning food simply because it has become cheaper than traditional fuel? At a time when millions of people globally face food insecurity, many will find the image of food in a stove disturbing.

That is exactly the point Hoffmann highlights. His experiment acts less as a how‑to guide and more as a provocation: what does it say about policy and pricing when calories for a plate can appear “worth more” than calories for a stove?

Energy crisis in Poland: why people look for alternative fuels

The wider context is grim rather than comedic. Poland has been hit hard by rising energy costs, and many households rely on solid fuels-wood, coal, or pellets-to get through winter. When prices surge, options narrow quickly, especially in rural areas and among lower-income families.

In recent winters, reports have circulated of people turning to unusual fuels, such as:

• oats or other grains
  
• maize cobs or maize meal
  
• out-of-date or damaged foodstuffs
  

In that sense, the Berliners experiment fits into a broader pattern: it illustrates how intense the pressure has become to find anything that provides warmth, even if the solution is short-term or ethically uncomfortable.

Limits and risks: why this is a bad idea outside a controlled test

However striking the footage may be, the hazards are equally real. Burning unconventional fuels without proper expertise can create serious problems:

• Heavy smoke and soot: fat and sugar can produce sticky deposits in the stove and flue.
  
• Fire risk: oily foods can flare unpredictably.
  
• Harmful emissions: incomplete combustion at the wrong temperatures may release toxic gases and fine particulates.
  
• Insurance issues: damage caused by non-approved fuels is often excluded.
  

Professionals generally advise against using any fuel a stove is not designed and certified to burn. This kind of stunt belongs in a controlled demonstration-not in everyday home heating.

Air quality and compliance (extra context)

There is also a wider impact beyond one household. Soot and particulates are not just a maintenance issue; they are a public health concern, particularly during winter inversion conditions when pollution can linger. Many countries tighten rules around solid-fuel burning, and chimney inspections often assume approved fuels with predictable combustion properties. Burning food products may undermine both compliance and safe operation, even if it appears to “work”.

Why fat burns so well-and what that says about our food

From a physics perspective, the outcome is not especially surprising. Fats and oils are energy-dense: 1 kg of pure cooking fat can deliver more than twice the energy of 1 kg of dry wood.

Berliners typically contain:

• a large proportion of vegetable oil or fat
  
• sugar, which also burns readily
  
• flour as a structural base
  

That energy density explains why such products are both high in dietary calories and oddly effective in a stove. It also underlines an uncomfortable parallel: something that can keep a stove hot for hours is rarely “light” in nutritional terms either.

What to take away from the stunt-beyond the show

Hoffmann’s video can be dismissed as a gimmick, but it exposes several sore points. First, it demonstrates how distorted pricing can become: a product that is manufactured, packaged, and transported can briefly undercut basic heating fuel. When that happens, the incentives are clearly misaligned.

Second, it highlights a pattern seen in every crisis: people default to what works immediately, even if it is not a real solution. Faced with a freezing home versus burning surplus food, many will choose warmth-not because they want to, but because they feel forced.

For anyone trying to heat efficiently and responsibly, it is worth looking beyond the headline sack price and checking:

• cost per kilogram
  
• energy content per kilogram
  
• compatibility with your heating appliance
  
• certification, legality, and safety
  

The 10 kg of fatty pastries in a cast-iron stove is not a blueprint to copy-but it is a stark illustration of how the search for affordable heat, the energy crisis, and moral boundaries can collide.