[quote=“mike_12”]I think if you are limited to splashing and shaking, and you figure you higher o2 concentration, chill your wort to just above freezing prior to doing the splashing.[/quote]It takes at least 24 hours to drop the temp of a fermenter to 32F in a fridge and then you would need to warm the wort back up to 60F to pitch. An O2 tank and stone get the job done in 60-90 seconds.
I was thinking lagers, I should have specified.
Nice book. Looks like you can read a lot of it online.
+1
Even with a lager you’d have to warm it back up into the low 50’s. I think we’d all agree that the aeration step shouldn’t take 2 days. If you accept that you need 8 to 10 ppm of disolved oxygen and that shaking and splashing won’t get you there in a timely fashion, the $40 to $50 for oxygen injection makes pretty good sense…
Also from that same reference: saturation at 50 degrees F, 12 deg. plato wort = 9.3 ppm.
To me, shaking and splashing (or mix-stir aerator, whip aerator, etc) is a good low tech solution for most homebrewed beers.
[quote=“mike_12”]“Yes, more specifics would be nice but I think the take away is that yeast need a wort with 10 ppm and “shake and splash” can never exceed 8 ppm no matter how long you do it.”
Here is something interesting that I have seldom seen referenced by homebrewers : The saturation point of Oxygen in water and wort is related to water or wort temperature. Reference the table on p. 360 of this work: http://books.google.com/books?id=zV9bpy … ss&f=false
The lower the temperature, the higher the saturation point of oxygen in wort. For instance, in 12 deg. plato wort, the saturation point is 10.4 ppm at 5 degrees C. At 20 degrees C, the saturation point is 7.4 ppm.
I have seen several homebrewer experiments that showed saturation or near saturation of O2 in short order, via splashing and shaking.
I think if you are limited to splashing and shaking, and you figure you higher o2 concentration, chill your wort to just above freezing prior to doing the splashing.[/quote]
Interesting chart. It shows the soluability though, or as you describe the saturation point which indeed is effected by temperature. What it doesn’t show is the effect of various methods on getting to that saturation point. The test I referenced was an actual measurement of the actual dissolved oxygen in a wort after various aeration methods. Again, 5 minutes of vigorous shaking in a 1.060 wort at 70 degrees only resulted in 2.7 ppm. In otherwords, the saturation point was never reached, not even close…
