Reusable jars for food: How sensible is that ecologically?

Image Source: Yvonne Koglin

The politically driven trend towards more and more reusable packaging does not stop at beverages and gastronomy. Other areas of application have come into focus. In the food sector, too, brand manufacturers are increasingly considering whether a switch to reusable packaging is advisable. However, the answer is often hindered by the not inconsiderable effort required for a comprehensive eco-balance. We show you the results of a research project that examined the question for tomato passata and almonds as examples. We provide a B+P rule of thumb that you can basically put in your toolbox. And we explain in an excursus which three factors are decisive for the ecological performance of reusable glass for food.


Traditional reusable systems still exist in isolated cases in the food sector, for example in the case of yoghurt jars. The fact that reusable glass has so far remained limited to individual cases is not least due to the return logistics, which represent a special and fundamental challenge with reusable packaging.

Against the backdrop of the massive regulations, brand owners must nevertheless consider whether a conversion of individual product lines to reusable packaging is (or must be) an alternative again from a market perspective. A fundamental question here is whether reusable glass has any ecological advantages at all. Unfortunately, this can rarely be answered adequately without the effort of a comprehensive eco-balance.


Results of the Innoredux research project

The research project “Innoredux – Business Models for Reducing Plastic Waste along the Value Chain: Pathways to Innovative Trends in Retail” comes up against this dilemma. As part of the research, it was also investigated whether reusable jars for food make ecological sense or not. Specifically, the project looked at two products for this purpose: Tomato Passata and Almonds.


Three reference cases were compared in the overview life cycle assessment of the packaging:

  • disposable bags made of plastic laminated film (delivery in a disposable paper bag),
  • unpacked (delivery in a reusable plastic bucket) and
  • returnable deposit jar (established deposit jar for yoghurt with an accepted circulation number of 50).

The result: The use of the reusable glass for almonds shows ecological disadvantages compared to the other two alternatives.

Causes: The reason lies primarily in the one-time use of the tinplate lid and the high weight of the returnable glass packaging – both in relation to the quantity of product transported and overall, in comparison to the lightweight alternatives. High distribution loads and disadvantageous packing efficiency are the result.


Tomato passata

In the overview life cycle assessment of tomato passata packaging, three reference cases were also compared:

  • Disposable glass,
  • One-way composite carton and
  • Returnable deposit glass” (based on the deposit glass for yoghurt; circulation number=50).

The result:

The use of the reusable glass jar for tomato passata shows ecological advantages compared to conventional disposable glass packaging. But the one-way composite carton also shows good life cycle assessment results.


Compared to disposable glass, reusable glass has advantages mainly due to its assumed 50 cycles and a correspondingly only proportionate energy input in glass production. The shorter distribution routes and the local/regional distribution structure also had a positive impact on emissions.


Classification of the results

Overall, it is clear that the use of reusable jars is not ecologically sensible per se and for all areas of application. It depends on the product to be packaged and its protection requirements, but also on the application context in which the packaging is used. The use of a reusable glass can have corresponding ecological advantages but also disadvantages.

Important for a good performance of reusable glass in the life cycle assessment are:

  • a high packing efficiency (high product volume per package),
  • high circulation figures,
  • efficient filling and washing processes and
  • a local/regional distribution structure for short transport distances.


Our rule of thumb for your toolbox

As soon as the packaging weighs significantly more than the product, reusable solutions tend not to have a positive impact on the environment.

  • Very light products such as tea are therefore not suitable for packaging in returnable glass containers. But products with a low packaging efficiency also limit the product weight because – as in the case of almonds or pasta, for example – there is too much air in the packaging proportionally.
  • If, on the other hand, pasty products such as tomato passata and apple sauce or other (liquid) preserves such as chickpeas or sauerkraut are packaged in returnable glass, this usually makes ecological sense. This is especially true in comparison to one-way glass.


B+P Conclusion

  • Reusable has development potential in the food sector as well – but not across the board and everywhere. The study can serve as a guide for food producers who want to approach the topic and it is helpful to select first suitable product categories.
  • If you find market companions with similar ideas for the suitable categories, you can even think about setting up a returnable pool. A recent example is provided by the Bitburger Group, the Krombacher Brewery, the Radeberger Group and the Warsteiner Brewery, which have founded a first pool for 0.33 l longneck bottles.


EXCURSUS: The basic eco-factors for reusable glass


Whether a returnable glass is ecologically sensible for a particular product depends on several factors. For the overall system to perform favourably, a good interplay is needed between:

  • packaging manufacturers,
  • reusable system operators and
  • necessary product manufacturing.

From the table you can see who should consider and could possibly influence which aspects.


3 central factors for reusable glass for foodstuff

The ecological performance of reusable food jars can be influenced from three sides:

  1. through the packaging itself, i.e. the specifications of the returnable glass,
  2. through the establishment and logistics of the reusable system as a whole, and
  3. through the packaged product.


Factors influencing packaging

A very decisive factor is the circulation rate in connection with the return rate. But transport routes, packing efficiency and (!) reusable lids can also make the difference.

  • The target should be a circulation rate of at least 50 and a response rate of at least 90 per cent.
  • The glasses should be as stable as necessary and as light as possible in order to achieve the high circulation rates.
  • Short distances and an efficient logistics chain are elementary for a good eco-balance, as reusable systems also require the return journey of the empty packaging compared to one-way packaging and reusable glasses are also relatively heavy.
    • If short distribution channels are not feasible, the complete conversion to returnable PET could also be interesting.
  • The packing efficiency of the packaging should be as high as possible. This is especially true for return transport. Reusable packaging that stacks well and is easy to transport makes a major contribution to efficient transport logistics.
  • Reusable lids make a difference. The disposable lid of reusable glasses is currently (still) a major negative factor in the environmental impact of reusable systems.
    • Reusable lids for returnable jars are currently a real gap in the market (and thus also offer great opportunities). The goal would be a reusable lid that achieves comparably high circulation rates as the container, is hygienic and easy to clean, and at the same time can be used practicably on different container shapes and for any products.


Factors influencing the cleaning logistics system

In addition to the disposable tinplate lid, the filling and washing processes in particular make a significant contribution to the overall environmental impact in the glass-refill system.

  • Due to the repetitive cleaning logistics in the value chain, even small improvements in the filling and washing processes can lead to a visible change and improve the eco-balance accordingly. Small improvements have a big impact due to high circulation rates.
  • Many factors can be examined and made more efficient. These include:
    • water consumption and efficient processes overall,
    • the use of rinsing and disinfecting agents,
    • easy-to-handle container shapes,
    • the utilisation of the dishwashers,
    • logistical efforts during the cleaning processes and
    • transport distances.
  • The character and implementation of the pool system also plays an important role. If a large pool of the same containers is used by different fillers and a large, regional network of return options for the empty containers is available, this not only reduces the number and distance of return trips, but the containers are also back in circulation more quickly.
    • If the transport kilometres of the pool system are comparable to those of alternative disposable containers, the reusable system usually does not pay off ecologically.


Factors influencing the product

The filling material or factors such as density and aggregate state play a decisive role in the assessment of the ecological sense of reusable glass containers.

  • Products with a low density and correspondingly a low quantity of packaged product per container are predominantly not suitable for the use of reusable containers (see rule of thumb above).
  • The density and aggregate state of the product also determine the possible packaging alternatives. For example, bulk goods are also suitable for unpackaged sale or can be packed in paper or a thin plastic film.
  • The regionality of the product also plays an important role. Regionally grown products that are also processed and filled regionally are better suited for packaging in returnable jars than products that are grown and processed in other countries. If filling already takes place in other countries, one-way packaging often has advantages due to its low weight.
  • The seasonality of the filling material is also a relevant factor. Seasonal products such as apple sauce or red cabbage are only harvested and packaged once a year. If reusable jars were only used for such products, it would take decades to reach the high circulation figures required from an ecological point of view. To counter this, pool solutions and the use of the jars for different types of products are important.

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