O2 and yeast

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May 12, 2024
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I am new to brewing and am ready to brew my first kit beer this weekend. When transferring from my 5 gal brew machine to my fermenter, should I let it pour out of the tap with as little agitation as possible? I have seen some guys stir there yeast into there wort saying the oxygen helps the yeast. Other brewers say keep oxygen out at all costs and don't stir your yeast in. That you should get your wort into your fermenter and just sprinkle the yeast on top. So what is the right way to transfer wort and how do you add yeast...dry sprinkle on top, add yeast and stir or pitch your yeast in water or a small container of wort and stir it in later. Thanks for you help!
At pitching, you want to give your yeast all the oxygen they need. At all other times, you want to keep your wort/beer as oxygen-free as possible. Commercial dry yeast does not need any oxygen at all. For a normal beer, up to 1.050 or 1.060, sprinkling a properly sized pitch of dry yeast on top of the wort is good enough. For a big beer, you'll want to get further into yeast handling with rehydration, starters, and such.
If you're using dry yeast you really don't need to oxygenate the wort. There are a few different ways to pitch dry yeast, which you can find described at the manufacturers' websites. The two most common are sprinkling on top of the wort once it is in the fermenter and at the appropriate temperature, and rehydrating in a small amount of warm water before adding to the fermenter.
For liquid yeast or yeast you re-use you should oxygenate the wort before or just immediately after pitching. However most dry yeast brands are saying that it is unnecessary. I haven't oxygenated my wort since about the first half dozen or so kits I use to use.

It likely doesn't hurt if you do oxygenate the wort and use dry yeast. Many kits supply dry yeast only and still tell you to shake the FV or otherwise oxygenate it. But they also are the same kit instructions that promote the use of secondary fermenters, which most of us agree aren't necessary for beer either unless you are doing special things toward the end of fermentation such as adding more fermentable products.

I just sprinkle the yeast on top of the already cooled wort when the FV is ready to be sealed up and airlock or blow off tube and bubbler installed.