German home canning rules: official advice vs. everyday practice

Yes, Germany has canning rules. No, most people don’t follow them.

Why the BfR matters in German home canning

In the U.S., the USDA’s canning advice is everywhere – they’re the ever-present authority, with detailed rules and a strong voice in every conversation about home food preservation. In Germany, we have the BfR (Bundesinstitut für Risikobewertung, or Federal Institute for Risk Assessment), which issues guidelines on many public health topics, including food safety. 

The BfR plays a much quieter role. I’d never even heard of them until I started digging into German home canning. Then I quickly discovered that their recommendations (1,2) differ from what most Germans (and even companies like Weck) actually do. 

Understanding the BfR positions and the reasons behind them helps explain the gap between “official advice” and “everyday practice” – and why that gap can be so confusing for home canners trying to decide what’s safe.

The official rules of the game: what the BfR says

The BfR draws a clear line between canning high-acid and low-acid foods. So far, so good.

High-acid foods – most fruits and properly pickled vegetables – are considered safe with a single boiling water bath. Their natural acidity prevents the growth of Clostridium botulinum, the bacteria that produce botulinum toxin.

Low-acid foods – vegetables, meats, soups, and such – are a different story. Here the BfR says a single boil at 100°C isn’t enough to ensure safety. To address the risk in low-acid foods, they recommend three options:

1. Pressure canning – heating the food to 121°C under pressure for at least 3 minutes at all points in the jar.
2. Tyndallization – also called fractional sterilization: heat jars to 100°C, rest them for 24–48 hours at room temperature, then heat again (sometimes twice more). The rest period lets spores germinate into regular bacterial cells, which are much easier to destroy in the second heating. (3)
3. Heating before eating – bringing home-canned low-acid food to a full boil before serving, which destroys any toxin that may have formed during storage.

They also advise discarding, without opening, any jar that shows signs of spoilage, such as bulging lids, unusual bubbles, or off odors.

Why the BfR is so cautious: the precautionary principle

The BfR follows the Precautionary Principle (Vorsorgeprinzip) in its work – an approach that prioritizes preventive action in the face of potential health risks. (4)

Practically, in the context of home canning, this means assuming the worst-case scenario (botulism) and designing guidelines to prevent it, even if the risk is very small. Their advice is meant to work in every kitchen – from seasoned home canners to first-timers – and even when conditions or ingredients aren’t perfect.

When it comes to low-acid canning, their caution is based on the fact that Clostridium botulinum spores are far more heat-resistant than the active bacterial cells they come from. At 100°C, it takes much longer to inactivate spores than at the higher temperatures that can be achieved with pressure canning. The BfR actually states that spores can only be destroyed at temperatures above 100°C (1,2), although scientific literature and food microbiology textbooks show they can be inactivated at 100°C, given enough time (5–7). (For more details about this, check out The boiling point myth – why you don’t need a pressure canner to kill Clostridium botulinum spores.) Traditional German water bath canning already accounts for this with its long processing times. 

Even so, the BfR advises pressure canning or successive heating through Tyndallization as added precautions for low-acid foods.

Real-world safety: why most German canners (and Weck) don’t follow all BfR steps

Here’s the problem: The BfR’s guidance reflects the most cautious scientific approach, but everyday practice in Germany looks very different. In my experience from participating in German canning groups, I find that expert home canners generally don’t use pressure canning, Tyndallization, or reheating for low-acid foods.

Why Weck and most canners skip Tyndallization

Weck’s position is based on over 120 years of experience and a track record with no recorded cases of botulism when their method is followed correctly. (8) Their system is built on several layers of safety:

• Pristine ingredients (einwandfreie Ware) – starting with fresh, undamaged produce or meat.
• Tested processing times – long enough to inactivate spores at 100°C without a second heating.
• Proper sealing – ensuring a strong vacuum seal that protects against contamination.
• Sensory checks before eating – examining jars for signs of spoilage like bulging lids, bubbles, cloudiness, or off smells.
• Heating before eating – for extra reassurance, especially with low-acid foods, bringing contents to a full boil before serving destroys any botulinum toxin that may have formed during storage.

Because these steps work together as a complete system, many German canners see no need for the added time, energy, and complexity of Tyndallization. 

In German online canning communities, it’s often described as outdated and unnecessary – a method that may once have made sense before modern refrigeration and tested processing guidelines, but isn’t part of standard home canning today.

That said, many experienced home canners in Germany feel that certain Weck processing times are still too short for specific foods. They report occasional spoilage and recommend following longer boiling times instead. The times I publish on this site reflect these more conservative, community-tested recommendations, drawn from people who have been canning successfully for many years. 

Why pressure canning isn’t common in Germany

Although the BfR lists pressure canning as a safe option for low-acid foods, it’s just not widely practiced in Germany. Until recently, pressure canners weren’t even available for purchase without importing them from abroad, and most German home canning traditions have been built entirely around the boiling water bath. For many experienced canners, it’s a case of “if it works, why change it?”

Read more here: Pressure canning in Germany – why Americans rely on pressure canners and Germans don’t

Two approaches, two risk perspectives

It’s not that one is right and the other is wrong – it’s a matter of risk perspective:

• Weck’s method is practically safe. The risk is managed to a level so low it’s not a significant concern in the real world, as proven by their 120+ years of history.
• The BfR recommendation is scientifically safer. It takes the already low risk and reduces it even further, accounting for variables and potential user error.

Weighing your options: Tyndallization or traditional methods?

Whether you use Tyndallization depends on the foods you’re canning, the quality of your ingredients, and how much additional precaution you want to build into your process. It’s about understanding the strengths of both methods so you can do what fits your kitchen and comfort level.

Traditional long-boil methods may be sufficient if:

• You’re following a tested, long-processing-time recipe from a trusted source.
• You’re using very fresh, undamaged ingredients.
• You’re meticulous about your canning process from start to finish.

Tyndallization may be worth considering when:

• You’re canning very low-acid, high-risk foods (e.g., green beans, asparagus, meats).
• Your ingredients are older or not in perfect condition.
• You’re new to canning and want an extra layer of reassurance.
• You want to reduce a very small risk even further.

If you understand the BfR’s stance and the real-world track record of traditional canning methods, you can decide which approach works best for you – with confidence.

Bringing it all together

Home canning in Germany sits at the intersection of science, tradition, and personal preference. The BfR builds its recommendations on a “worst-case scenario” model, aiming to make every batch of food as safe as theoretically possible. 

Weck and most experienced canners work from a proven, practical system that has been safely used for generations. It’s a good example of the difference between what’s scientifically proven to be absolutely safe and what’s practically safe enough in real kitchens. (I explain that distinction in more detail in this post: Is any home canning method 100% safe? A science-based answer.)

Somewhere in the middle is where most home canners make their decisions – balancing official advice, tradition, and what makes sense in their own kitchens. The BfR recommends two options for low-acid foods: pressure canning at temperatures above 100°C, or successive heating through Tyndallization. 

By knowing exactly what the BfR recommends, why they recommend it, and how those recommendations differ from everyday practice, you can approach canning with both confidence and clarity.

Whether you choose Tyndallization, stick with traditional long-boil methods, or use a pressure canner, the most important factor is doing each step with care. That’s the real key to safe, delicious food that lasts on your shelves.

New to the method? This intro to German water bath canning covers everything you need to know.

References

1. German Federal Institute for Risk Assessment. Rare but Avoidable: Questions and Answers about Botulism – Updated BfR FAQ.; 2023. Accessed May 25, 2025. https://www.bfr.bund.de/en/service/frequently-asked-questions/topic/rare-but-avoidable-questions-and-answers-about-botulism/
2. BfR. Verbrauchertipps: Schutz Vor Botulismus Durch Lebensmittel.; 2020.
3. Gould GW. History of science – Spores: Lewis B Perry Memorial Lecture 2005. In: Journal of Applied Microbiology. Vol 101. ; 2006:507-513. doi:10.1111/j.1365-2672.2006.02888.x
4. Mehr Vorsorge, mehr Sicherheit? Notwendigkeit, Machbarkeit und Grenzen des Vorsorgeprinzips: 4. BfR-Stakeholderkonferenz.; 2011.
5. Hartwig G, von der Linden H, Skrobisch HP. Grundlagen Der Thermischen Konservierung. Behr; 2009.
6. Heiss R, Eichner K. Haltbarmachen von Lebensmitteln Chemische, Physikalische Und Mikrobiologische Grundlagen Der Verfahren. 1st ed. Springer; 1984.
7. Diao MM, André S, Membré JM. Meta-analysis of D-values of proteolytic clostridium botulinum and its surrogate strain Clostridium sporogenes PA 3679. Int J Food Microbiol. 2014;174:23-30. doi:10.1016/j.ijfoodmicro.2013.12.029
8. Röder J, ed. Das Original Einkochbuch. Mohn Media Mohndruck, GmbH; 2025.