Oxygenating Wort

Professional breweries diffuse/inject oxygen into the wort as it travels from the heat exchanger (cooling device) to the fermentation tank.  The purpose of this is to effectively fuel the yeast so that it is more effective during fermentation.  It allows the yeast to ferment more quickly, at lower temperatures, and convert a significantly higher percent of the total sugars in the wort (high attenuation). 

I was able to get a very small tank and a high PSI regulator from a local gas and welding supply store.  This method uses the Oxygen very slowly, so a small tank is a good idea.  I attached a line to the regulator and reduced it down to the size where I could hose clamp a basketball inflator needle in the end.

For my first two beers which used oxygen I injected it directly through the inflating needle into the tube directly before the fermentor.    I used a slow bubble for both.  The first beer began fermentation at 68F and reached a gravity of 1.004 within 7 days!  This is too dry for most people and needs more body to be a balanced beer.  The next beer reached 1.005 within its first week.  My target Final Gravity for both brews was around 1.011 and without oxygen should have been relatively accurate.  It should also be noted that these two brews have approximately 1% extra alcohol...

For the next oxygen-massaged beer I intend to increase the unfermentable sugars and use a minute amount of oxygen for half of the beer as it flows to the fermentor so that it will ferment healthily and maintain some body (FG approx.=1.010).

This is definitely a useful tool and I'll let you know what the optimal situation for me turns out to be.

A note on Eisbrau... (or why I thought my tolerance left me)

Ice beer is what's created when the water in an already fermented beer is frozen and removed, leaving a higher concentration of alcohol in the product.  Eisbocks are a great example of this style from Germany.

The last two weeks I've had a keg of 5.8% beer on tap.  This last four or five days, however, I've been feeling the alcohol of the beer much more quickly and strongly.  I have also noticed a change in taste which I attributed to drinking the same brew constantly.  It wasn't my tolerance or my changing palate.  The refrigerator housing the beer was just a few degrees too cold and was slowly freezing the water.  At this very moment I have a sample of the beer sitting with a hydrometer in it waiting for it to warm up and the head to recede.  I'm going to compare this reading of the remaining sugars in the brew with what it was when kegged to measure the difference in gravity and multiply that by the original alcohol content.  See you in a moment...


Here are the results:

     OG @ kegging = 1.008
     OG @ current  = 1.013

     [13/8]*5.8 = 9.5% Alcohol



Lesson #1:  an Ice Beer is easy to produce (in my case by accident)
Lesson #2:  when an Ice Beer is produced it has the potential to be very strong.
                               5.8% to 9.5%  is quite a significant change!!!

Be aware and, if you'd like, make one intentionally!