Headspace and Aeration Question

[craigthunder]

I'm still in my beginning stages of being a homebrewer so this maybe a bit of a newb question.

I'm planning a 2.5 gallon batch to be fermenting in a 3.5 gallon bucket. I plan to rack to secondary in another 3.5 gallon bucket and dry hop the last few days. Should I be concerned about oxidation or is this bucket going to be small enough?

If i shake the bucket vigorously will this be adaquet aeration for a good fermentation?

 

[ncbrewer]

2.5 gallons in a 3.5 gallon bucket is too much head space for secondary. I'd say you're much better off to skip the secondary.

As far as aeration, you'll get different opinions. I think shaking the bucket will be fine if you're using dry yeast. It might be marginal for liquid yeast.

Welcome and good luck.

 

[craigthunder]

So I should probably ditch the dry hop idea with this one? I'm assuming opening the llid for the hops addition would let the co2 escape and oxygen in? Or does the co2 settle on top of the wort?

 

[TANSTAAFB]

Just toss your dry hops into the primary. I use a bag to contain them and make it easier to remove...Uses to use a 1gal paint strainer, now I use my new Wilserbrew hop bags 😎

 

[mongoose33]

So I should probably ditch the dry hop idea with this one? I'm assuming opening the llid for the hops addition would let the co2 escape and oxygen in? Or does the co2 settle on top of the wort?

CO2 does not form a blanket on top of the beer; there have been several threads here discussing that. I think people have that sense from seeing dry ice sublimate into gas which immediately drops down. But that gas is very cold, which is why it's settling on the bottom of whatever it is in. Once warmed to the same temperature of other gases, it no longer forms a "blanket."

It's good that you're thinking about how oxygen affects your beer. Prior to fermentation, O2 is good. Shaking the bucket, splashing the wort as it is racked into the bucket--these are likely good enough especially for dry yeast. Yeast need O2 to help form cell walls, which means it's necessary at the outset.

But at the end, O2 will especially hurt hop essences in beer, either aroma or flavor. You may also get an oxidation flavor like cardboard.

How to avoid? One is that you really don't need to secondary. That's only necessary if you're aging the beer a long time, or need to free up a primary fermenter for more beer, or maybe some special flavor you need to work for several weeks.

Another is to avoid the splashing and shaking that is a good thing at the beginning, at the end. I keg, so I do direct transfer of the beer from the fermenter into a keg that has been purged of O2 and is pure CO2. I feed the displaced CO2 from the keg back into the fermenter to reduce any O2 that may be attacking the beer from the surface.

And yet, there are a lot of brewers who bottle who produce great beers. Don't be nutso about it, just try to reduce O2 exposure post-fermentation where you can.

Don't ditch the dry-hop idea; just do as TANSTAAFB suggests, just put them in the primary when you were normally going to dry hop in the secondary. Just crack the lid, slip the hops in (in a bag is good), and gently reseal the lid.

 

[craigthunder]

Thanks for the advice.

One batch will be using dry yeast. The second is liquid. Would a paint stirrer on a drill get the oxygen i need? I dont have a fish tank pump or o2 tank/stone.

 

[rhys333]

I agree with above comments. Add hops to primary and ditch secondary unless you're planning extended bulk storage. I drop my hops right in. Most fall out and the rest are captured in the hop bag I tie to the tail end when siphoning. I just make sure to sterilize the bag with a 15 minute boil before attaching.

As for adding O2, agitating the wort via shaking or vigorous stirring works equally well for both dry and liquid yeast.

 

[kh54s10]

When your wort is cool and before you add the yeast slosh it around as much as you can for 5-10 minutes without spilling it all over the floor. Liquid yeast do best with more oxygenation, Dry is engineered so oxygenation is not critical.

Dry hop in primary. Do not be too concerned with oxidizing your beer, just don't slosh much. Transferring and hop addition is more likely to oxidize the beer than dry hopping in primary.

As to the co2 layer. It will be there for a while, but when the fermentation slows and co2 production stops the gasses will intermix and your co2 "layer" will be less effective in keeping oxygen out.