Compressed Air & Flow Meters

[stbenjamin]

We are planning to switch form O2 to compressed air for our yeast aeration since our new brewhouse came set up for that. We had not been using a flow meter on our O2, though now I see that we should have been. When we switch to air do we want to use a flow meter?

[brewgood]

Need for flow meter

Yes, measure the flow. I assume you are filtering. Recommend that you Measure DO.

[Yeast]

We are planning to switch form O2 to compressed air for our yeast aeration since our new brewhouse came set up for that. We had not been using a flow meter on our O2, though now I see that we should have been. When we switch to air do we want to use a flow meter?

if I remember correctly it's hard to get DO over ~12PPM with air even with a stone. you usually one 1 ppm per plato so any beer at or around 12 plato should be fine if you just pump air at any speed. with O2 you definitely want a flow-meter. if you cannot afford a DO meter the next best thing is to do a cell count and see if you get appropriate growth. IE your 12 plato beer should have 9-12 million cells per mL and the next day have 18-24 then 36-48. you should get three generations out of it quickly and have a short lag phase.

you can't get to oxygen toxicity with just air so it may be worthwhile to just bubble air through the fementor even after the transfer is done for a while. The yeast assimilate the O2 very quickly