October 9, 2017

Steel Versus Plastic: Not All Kegs are Created Equal

You’ve spent hours upon hours crafting the perfect brew. Days, weeks, months – just “pouring” over every single detail. And now it’s time to bring your finished product to the masses. But before your masterpiece can make its delectable debut, you first need to make an important decision: plastic or steel?

There are so many factors to consider when it comes to buying kegs: material, ease of use, weight, safety, cost, and efficiency, among others. As a brewer, it can be difficult to discern which among these is of the utmost importance. We also realize these priorities may not always be the same for every brewer. But to help you make heads or tails of what matters the most when shopping, we’re breaking down what to expect from two types of kegs so you can streamline your purchase and have confidence and peace of mind in your fleet.

Why stainless steel matters

According to Blefa GmbH & Co. KG (Franke Beverage Systems), there are several valuable benefits to choosing stainless steel kegs over plastic kegs. With stainless steel kegs, you’re getting durable, sterile containers. They’re easy to handle, and they provide automated cleaning and filling through the valve in a closed system. Additionally, stainless steel kegs are safe, are inexpensive to handle, and they’re a low cost per glass of draft beer – which explains their popularity. Satellite Logistics Group (SLG) estimates stainless steel kegs are used on an average of 150 times in a 30-year period (at five turns per year).

Taste the difference

Stainless steel has become an essential investment for brewers who are interested in delivering the best product to their consumers – both in quality and safety. And the difference is palatable. In a controlled scientific experiment conducted by Miguel Hernandez University (MHU) for global keg manufacturer Thielmann, beer that was stored in stainless steel kegs kept its sensory values constant during the six-month trial period. Beer stored in plastic kegs, on the other hand, became progressively altered during the storage period.

MHU examined several other factors to discern an overall quality analysis. These included, color, foam head retention, different flavor retentions, bitterness, carbonation, body, and aftertaste.

Here are MHU’s findings:

  • CO2 concentration in keg headspace is not affected by the type of keg used.
  • Beer preserves its initial color for longer periods when stored in stainless steel kegs, whereas beer in plastic kegs is oxidized. This fact is supported by the chemical analytical results, as well as by the sensory analysis.
  • Bitterness is an attribute not affected by the type of keg used.
  • Sensory analysis shows that beer stored in stainless steel kegs preserves its initial characteristics.
  • As a final conclusion of the tests developed, it can be confirmed that beer storage in stainless steel kegs results in a better preservation, given that the beer keeps its original physical, chemical and sensory properties for longer periods of time.

Environmental benefits

Beyond protecting the quality of your product, stainless steel kegs also play a role in protecting our environment. Everyone wants to do their part to make our world a greener place. Waste reduction and recycling are of special importance when shopping for a keg. With regular maintenance, stainless steel kegs can last for more than 30 years, whereas most plastic kegs are typically designed for single use. Additionally, after a steel keg has run its course, the steel is 100 percent recyclable, which is incredibly beneficial to the environment.

Pass on plastic

Beyond the benefits of utilizing steel, there are reasons that some brewers still choose to use plastic kegs. Plastic kegs are lightweight, stackable, are less likely to be stolen and/or go missing, and they’re affordable when purchased new.

All the reasons listed above might sound appealing, but there’s a catch. (Actually, there are several.) Before opting for plastic kegs, consider the following points:

Plastic takes longer to cool down than steel, which can have implications on the integrity of your brew and the keg’s stability itself. According to the Brewer’s Association (BA), extreme heat and exposure to sun can affect the plastic keg, which can become a liability. The BA report states that direct exposure to UV light, heat and moisture can degrade the molecular structure and deteriorate or deform plastic molded containers, which will affect/change the pressure tolerance of the keg. And every brewer should feel the pressure to pressure test their kegs, because no one wants a dangerous incident. According to BA: “Pneumatic testing to burst failure can be extremely violent and dangerous.” Not exactly the kinds of adjectives you’d hope to use when describing your kegs.

Plastic kegs are also not always easy to integrate into your production line. According to BA, many plastic kegs are not compatible with universal filling systems or coupling devices. That means, in order to use them, you’ll need to research and possibly acquire special equipment that will properly function with the design of your specific plastic keg.

Plastic is also less durable. The material used for plastic molded kegs is more susceptible to damage during transportation and storage when compared to its stainless steel counterpart. BA advises: “Special attention should be given to pallet decking for nails, fasteners, screws, broken deck boards or debris, etc. which that could damage the keg.”

So, while buying a new plastic keg may have some short-term cost savings, other kinds of costs can ultimately catch up with you. And using a less durable product that takes longer to cool down can compromise the quality of your product, which is consistent with MHU’s findings. And that’s a risk many a brewer is not willing to take.

Ultimately, whatever you choose to transport your beer in is entirely up to you, the brewer. But no matter your taste – stout or ale, hefeweizen or IPA – we want to ensure the integrity of your brew is intact. And you can rely on SLG every step of the way. We can help your product get where it needs to go. More important, we expedite the return of your keg asset to your brewery to reuse. Our various beer-centric technology solutions provide valuable analytics that will enable you to make smarter business decisions. We’re here to help, and there’s no problem too big or too small – and no distance too far for us to handle.

If you have any questions – don’t hesitate to reach out!