Is the shelf life of your beer important to you or your customers?
If so, you’ll need to know a thing or two about total package oxygen (TPO).
What is Total Package Oxygen? – TPO
Total Packaged Oxygen, or TPO, is the gross amount of oxygen present when a beverage is packaged. That means the oxygen inside the liquid as well as the air at the top of the container.
When mixed with air, the amount of packaged oxygen in the product can lead to a chemical reaction called oxidation. Oxidation can unfortunately have tragic effects on your shelf life and flavor!
Measuring total package oxygen is essential for determining a beer’s shelf life.
As such, understanding, measuring and controlling total package oxygen is vital to preserving flavor and consistency.
TPO can come in the form of:
We’ve established the amount of oxygen in a packaged product, called TPO, can have significant impacts on your drink’s flavor and shelf life.
But where exactly does the oxygen come from?
Total package oxygen comes in three forms: dissolved oxygen (DO), headspace oxygen (HO), and encapsulated oxygen.
Dissolved oxygen (DO)
Dissolved oxygen is the amount of oxygen present prior to and during the filling process.
How a can is filled will have an impact on dissolved oxygen. Wild Goose canning systems are engineered to minimize DO at every station on the machine: pre-purging, patented high/low flow filling method, and the “DO Buster” CO2 Hood, a laminar CO2 blanket.
Most products have some measure of oxygen present when packaged, but the amount can vary depending on the fermentation process, handling, and filling procedure.
In beer production, for example, oxygen plays an important role in the fermentation process. Specific amounts are needed during this phase to reach your desired carbonation level, as well as alcohol percentage.
When fermenting wine, controlled dissolved oxygen is required to reach intended flavors, aromas, and color. Unbalanced flavors and volatile wines are often the result of improper levels of dissolved oxygen during the fermentation process.
Most canned or bottled beverages and soft drinks also require a delicate mix of dissolved oxygen. Excess amounts can lead to spoiled flavors, the beverage going ‘flat,’ or even loss of nutritional value.
Oxidation occurs quicker with higher amounts of dissolved oxygen. So, understanding and controlling levels during production is vital.
Headspace oxygen (HO)
Hold a beer or wine bottle upright and notice the pocket of air at the top. That’s the bottle’s headspace. This headspace exists in cans too, but is a little harder to see through an opaque material!
Headspace is the air left over inside a can or bottle after the product has been packaged and sealed.
To put it simply, headspace is the air trapped inside the can or bottle. There’s typically more headspace oxygen than dissolved oxygen. The two together make up TPO. Headspace varies depending on the beverage and container.
It may seem like wine, beer, and soft drink bottles are air tight. That must explain why they’re so difficult to open, right?
Almost. Certain closures such as corks or screw-tops aren’t completely impermeable. Because trace amounts of oxygen can squeeze through the cork or cap itself, oxygen levels can increase slightly after packaging. This newly discovered phenomenon is known as premature oxidation, and it’s understood to happen shortly after bottling.
However, because the beverage packing community still has much to learn about this relatively new revelation, the effects and causes of premature oxidation are still being studied.
How HO and DO contribute to Total Package Oxygen
Total package oxygen hasn’t always been a consideration in the beverage industry. While many producers have traditionally focused on controlling dissolved oxygen levels, product innovation and fierce competition has led to the creation of beverages that require specific production factors and more elaborate testing methods.
As a result, the industry has re-evaluated their approach to packaging in order to sustain longer shelf lives and create more robust, imaginative beverage flavors. This has led to more widespread efforts to measure total package oxygen in order to attain high quality and consistent flavors.
Why measure TPO
In addition to increasing shelf life and sustaining flavors, there are other benefits to measuring and controlling TPO.
First, recording oxygen levels, and understanding where the oxygen came from, is key to process control, product improvement, and quick identification of any problems you may encounter during production. Properly measuring TPO can help you alleviate problems before they start.
After being packaged, beverages are still prone to additional amounts of oxygen through diffusion. Measuring and controlling TPO can ensure longer shelf life, increase profits, and reduce waste.
Moreover, because much of the industry has moved to consistent monitoring of TPO during production, measuring TPO has become standard and essential to compete in the market.
How TPO should be measured and controlled
TPO is essentially an amalgamation of dissolved oxygen and headspace oxygen. Instrumentation is available that can precisely gauge the amount of total package oxygen present in a container.
Following standard operating procedures (SOPs) for TPO measurement is critical. Consistent methods, time, and instrument calibrations are important for accurate measurements and ongoing oxygen reduction efforts.
Dissolved, headspace, and encapsulation oxygen all contribute to total package oxygen.
Constant monitoring of TPO can go a long way in preserving consistent flavors and keeping great tasting products on the shelf longer.
As the new industry standard, proper control and measurement of total package oxygen is essential to successfully launching and selling a new beverage product. Choosing the right canning or bottling machine to ensure low DO and, consequently, ensuring your beer has a long shelf life is of utmost importance.