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Keg knowledge
What comes up in the workshop every day but is written down nowhere. Technically documented, with the sources disclosed – and without prettifying the figures that do not suit us.
Workshop – assessment and decision
Buy-back and valuation
What is my used keg still worth?
Five price factors, the complete damage catalogue, the ownership question with other breweries' kegs and a checklist for the ten minutes before the call.
Condition assessment
How many cycles does my keg have left?
The clock is not ticking on the keg but on the spear. Six fault patterns, five checks to carry out yourself, documented limits and the complete scrapping criteria.
Economics
Refurbishment or buying new – which pays?
Four routes instead of two, compared by cost per keg and year – including the strongest objection to refurbishment and how to test it.
Life cycle assessment
From when does a keg pay off for the environment?
Two life cycle assessments, two break-even points – 15 to 20 cycles in one, 38 in the other. Why both are correct, from what distance the sign flips, and a calculator for your own fleet.
Ownership and return of kegs
I have another brewery's keg – what now?
A deposit transfers no ownership, and § 935 BGB rules out acquisition in good faith. An identification guide and the procedure that ends without trouble.
New on the blog
Every article, filterable by topic, is in the blog overview.
Spears
The five spear types, finally explained
A, S, D, G and M side by side – dimensions from the production drawings, parts lists, exploded views. With two corrections to common trade figures.
Workshop
What really happens during a complete overhaul
Twelve steps on the keg, six on the spear – written out in full. With the three questions that decide the quality of an overhaul and that appear on no process list.
Terminology
Keg vocabulary in six languages
79 technical terms in German, English, Polish and French, searchable. Not a word invented, every one documented – and the gaps identified.
Return of kegs
What keg shrinkage really costs
For Germany there is no reliable loss rate. Four figures from four countries – and the calculation showing why eight percentage points of return rate decide a factor of five in service life.
Designs
DIN, EURO or SLIM
Dimensions, operating pressures and stacking behaviour of the three designs – with a scale drawing, a complete dimension table and the limitation that counts for summer export.
Spears
Which coupler fits which beer?
Four dependencies on which every blanket list fails – and why of all countries Germany has the poorest data.
Glossary
Seven terms nobody explains
Beerstone, bursting disc, pickling, residual pressure, number of cycles, jacketing, spray shadow. Documented – and for two of them with the result that the common term is the wrong one.
Technology and safety
Case study · TU München
At 35 degrees the seal gives way
Why slim kegs start to leak in summer export – and why it is not down to overfilling. A report by the Weihenstephan research centre, recalculated.
Interactive
Keg cleaning in section
Fifteen steps through the cleaning plant, followed in a sectional view – with the temperature and concentration limits the spear can take.
Interactive · 3D
Keg Explorer
A DIN keg to rotate, dismantle and cut open. All eight components explained individually, from the chime to the down tube.
Hygiene
Environment and circular economy
Single-use versus reusable
The single-use keg, as honestly as possible
There is exactly one independent life cycle assessment – and it was calculated with data from the single-use manufacturer. We set out what follows from it, including the seven points that speak against our own position.
Recycling
What is left of the keg at the end
The much-quoted 95 per cent includes downcycling into carbon steel. Only about a quarter of the stainless steel comes back as stainless steel – as can be read in the very source the figure comes from.
Law and regulation
EU Packaging Regulation
What the PPWR requires of the keg
"Kegs of any size and any material" is what the text of the regulation says. Annex VI Part B describes the refurbishment in six steps, Article 12 requires an open data carrier that counts cycles – and neither of them applies from 2026.
Statistics
The quota the keg does not appear in
78.1 % reusable share for beer – the figure is correct. On page 14 of the UBA report it says that fill sizes above ten litres are expressly not included. The Brauer-Bund states it itself, just more quietly.
Tools
Calculate instead of guessing – every assumption disclosed and open to change. To the overview.
Where our figures come from
Every technical figure on this website is either sourced or marked as our own operating data. The full list of sources shows what that rests on – and where the evidence is thin.