I wanted to talk about the oxidation off flavor in beer first because that is the one that stands out the most to myself, and if you bottle your homebrew i believe that is the most common off flavor. I was talking to someone in the shop the other day, and i was talking about how every person has certain sensitivities to different flavors, there are some off flavors i cannot detect to save my life, however oxidation i can pick up a mile away! So below are some of my thoughts on it.
Oxidation is when oxygen is introduced to your beer post fermentation, but remember oxygen is great for your wort before you ferment. Breweries implement extensive controls in order to limit the oxygen exposed to their beer after it is fermented because it is probably the number one killer of beer over time. Breweries will purge their brite tanks with CO2 before transferring the beer from the fermenter. They will push their beer from the fermenter to the brite tank via CO2, and they will purge all of their packaging (cans/bottles/kegs) with CO2 before filling them, and even after all of these measures are taken, breweries still worry about oxidation.
Overall i believe very few homebrewers take these same measurements mentioned above, but if it is the number 1 killer or concern with brewers, what can you do to limit this effect?
Below are some steps that I would recommend:
#1) Limit the amount of times you rack your beer.
Typically the steps outlined for homebrewing is ferment for 10-14 days, transfer to a secondary for another 14 days, transfer to a bottling bucket, and bottle.
What i generally tell people is take about the bottling bucket step, and bottle from your secondary. This eliminates one transfer, which eliminates that additional exposure to oxygen.
Homebrewers will transfer from the secondary to the bottling bucket in order to add dissolved sugar back into the beer for carbonation. typically you will take 4 or 5 oz of corn sugar dissolve it in 1 to 2 cups of water and transfer the beer onto that sugar solution. I am typically against this, my main thought first is how do you know if that sugar is equally dispersed throughout the entire solution? It rarely is so what you end up with are some bottles being over carbonated, and some bottles being under carbonated. The best solution that i can think of is using carbonation drops these drops are great, you put one to two drops in each bottle and transfer the beer from the secondary into your bottles. This way you know each bottle has the same amount of sugar for equal carbonation, and secondly you just reduced a transfer of beer, which reduced exposure to oxygen!
#2) Use oxygen absorbing caps after you bottle your homebrew. whenever you get done filling your bottles there is always airspace in the neck of the bottle, this holds air, and that air has oxygen. the oxygen absorbing caps will remove that oxygen from the bottle, again reducing the oxygen that the beer is exposed to. Be sure to understand those caps, most of them are activated by water, so if you preclean your caps in a water solution, there is a chance that you remove that oxygen absorbing ability before you even cap your bottles!
#3) Probably the most important piece is after you get done bottling and capping you need to let your beer sit out in warm temperatures, typically 65-68 degrees for at least a week so the yeast can eat up all the new sugar in the bottles and carbonate the beer. A lot of people will let their homebrew beer sit out at the temperature, put a few in the fridge, drink those, a few weeks later put more in the fridge, etc etc until all the beer has been consumed. oxygen is in your beer, it is in every beer, homebrewer or commercial brewer. What speeds up the process of oxidation in your beer is temperature. If your beer is kept cold around 40 degrees your beer has the chance of lasting up to 6 to 9 months, if your beer sits out at 65 degrees that shelf live drops to about 30-45 days, it your beer is at 75-80 degrees the shelf live is about 2 weeks. Once your beer is carbonated, put all of your beer in the fridge it will last longer and taste better!
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