Packaging
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Packaging is when the brewer moves the beer/wine into a container such as bottles, kegs, or cans.
total packaged oxygen might be as low as 0.1 mg/L with modern filling equipment.[1]
Limiting dissolved oxygen levels in finished beers to ≤50 ug/L should prevent most undesirable effects on flavor and haze stability50. Quality control criteria recommends 0.2 mg/L or less of dissolved oxygen for packaged beer10,66 and modern filling equipment is capable of achieving <0.1 mg/L total package oxygen.[2]
After fermentation beer is vulnerable to oxidation. While active yeast is still in suspension much of the oxygen can be scavenged. In the absence of active yeast, oxidation will occur leading to the staling reactions described earlier. Measures must be taken to avoid oxygen ingress:[3]
- All tanks should be blanketed with inert gas (carbon dioxide or nitrogen)
- De-aerated water should be used to chase through beer transfers.
- All additions and dilutions should use deaerated water.
- Flush all bends and fittings with de-aerated water
- Attention should be paid to prevent leaks at pump surfaces, joints etc where air can gain access
- Pipework should be designed to be fully purged.
- Processing large volumes of beer into large tanks helps minimise oxygen pick up.
- Automation should be used to turn off pumps when vessels and dosing pots run empty.
- Inert gas used to undercover flush of centrifuges
- Effective oxygen removal from de-aerated water.
Poor pipework design can lead to oxygen pickup. Through careful operation and good process designs oxygen pickup can virtually eliminated. Beer should be presented to the packaging lines with less than 50 ppb dissolved oxygen. Packaging (small pack filling) Inevitably during small pack filling (bottling and canning) a small amount of oxygen pick up is inevitable. Developments in packaging line design have been made to minimise exposure to oxygen:[3]
- Counter pressure filler bowl with inert gas
- Flushing can or double pre evacuation of bottles with inert gas
- Fobbing control and gas flushing to reduce air in head space
- Packaging lines surrounded by inert gas tunnels
- The use of oxygen scavenging barrier crown corks can provide protection against oxidation
With the latest technology designed to reduce oxygen pickup it is now possible to produce beers with less than 100 ppb total in package oxygen. All Brewers should be capable of achieving less than 500 ppb. total in package oxygen. Keeping the oxygen content down in the finished product makes a very significant contribution to delaying the onset of staling.[3]
Yeast is an efficient scavenger for entrained air and so oxygen pick-up in beer that contains yeast is much less damaging than in bright beer.[4]
- Derdelinckx, G.; Vanderhasselt, B.; Maudoux, M.; Dufour, J.P. Refermentation in bottles and kegs: A rigorous approach. Brauwelt Int. 1992, 2, 156–164.
- The influence of assortment of beer on their antioxidant / pro-oxidant capacity and phenolic fingerprint
See also[edit]
References[edit]
- ↑ Zhao H, Zhao M. Effects of mashing on total phenolic contents and antioxidant activities of malts and worts. Int J Food Sci Technol. 2012;47(2):240-247.
- ↑ Aron PM, Shellhammer TH. A discussion of polyphenols in beer physical and flavour stability. J Inst Brew. 2010;116(4):369–380.
- ↑ a b c O'Rourke T. The role of oxygen in brewing. Brewer International. 2002;2(3):45–47.
- ↑ Lewis MJ, Bamforth CW. Chapter 12: Oxygen. In: Lewis MJ, Bamforth CW, eds. Essays in Brewing Science. Springer; 2006:131–142.