Flavour and extension of shelf life are the two main reasons why hops is so important for blended beer:
- Hops is the plant whose flower imparts the famed bitter taste to beer. The three main components of beer are malted barley, water, and yeast. These make the beer taste excessively sweet and dull. The hops flavour balances them and lends the characteristic taste to beer.
- Another contribution of hops to blended beer is extension of shelf life. Hops acts as a kind of natural preservative.
It goes without saying that hops can play its intended role only when available in the purest possible form. This is where thecarbon dioxide (CO2) supercritical fluid extraction (SCFE) comes into play. The critical temperature of carbon dioxide is 31.1 deg-Celsius, which is around the room temperature. The process temperature of CO2 SCFE is also slightly more than the room temperature.
As a result, hops extracted via carbon dioxide SCFE:
- Does not get thermally distorted and provides the required flavour to beer; and
- Maintains the integrity of the hop flavour for a longer duration thereby extending beer’s shelf life.
Beer and blended beer industry also use a two-step CO2 SCFE process to extract aromatic or essential oils which provide more flavours to the beverage.
Customers these days are ready to shell out more than just a few dollars more for beers and alcoholic beverages laced with premium flavours. Again, the flavours will taste authentic only when extracted in their pure form. Or their relatively pure form at the very least. Selective as it is, the supercritical extraction process makes itself very useful for the alcoholic beverages industry.
At the root of the selective nature is the mode of operation of the process. It uses a supercritical fluid (SCF) whose solvent power rises and falls respectively with increase and decrease in pressure. Solvent power refers to its capacity to dissolve compounds from the raw material. What is even more important is that at a certain pressure, the SCF will dissolve a certain compound and leave most other compounds alone.
Selectivity means that the process finds applications in making:
- Low alcohol and no alcohol beverages; and
- Beers and spirits with premium flavours.
And, it does so without affecting the other, desirable properties of alcoholic beverages. Wine, for example, includes over 800 compounds. SCFE removes only those molecules that impart the alcohol content to wine while leaving alone the other necessary compounds.