Oxygenating the wort

[James85]

Hi all I have been brewing for a few years now and due to time and space constraints I'm only able to brew k&k. I have had great success with all the coopers kits i have made but i was recentily told to shake the fermented to oxygenate the wort before pitching the yeast. Is this a good idea or have I been given a bum steer? Thank you in advance

 

[chunckious]

I believe that it is recommended James, I do.
I'd like to hear from the more experienced if you can over-oxygenate the wort. I get a slight cardboard taste right at the back of the palate, starting to wonder if it has anything to do with aeration of the wort.

 

[pk.sax]

From all accounts you cannot oxygenate your wort enough by just shaking etc. no chance of over oxygenating. Can't comment on the cardboard there Chuk.

A friend of min has been sanitising a stick blender and giving his wort a mighty thrashing. I believe his beers are some of the nicest tasting I've tasted. She'll be right mate.

 

[chunckious]

Thanks PF, I'll start looking elsewhere. That leads me back to astringency theory.

 

[James85]

So does oxygenating the wort make the fermentation happen faster or better?

 

[manticle]

If beer is oxygenated (as opposed to wort) it can lead to cardboard. In my experience astringency is more focussed at the front and side of the tongue and is best likened to sucking on a teabag.

Oxygenating wort helps healthy yeast grow which in turn encourages quick, solid, clean fermentation
Oxygenating beer encourages/accelerates staling reactions.

 

[chunckious]

Thanks manticle. I'm trying to think of the processes of oxygenating beer.
Poor/rushed racking technique of beer into the keg?
Gunk in the beer lines/glass filling technique?

My apologies James......thread hijack. Ignore me. EDIT

 

[grantb]

If you have time, this is a great watch. Long talk about yeast from a lab tech at White Labs. There is a section where they cover the benefits of aerating the wort and how effective the different methods are. I found it incredibly insightful.

http://youtu.be/2vELwUsBmWQ

 

[Black Devil Dog]

Splashing, shaking, whipping :blink: or stirring are some ways of oxygenating your wort. They're relatively inefficient compared to pumping pure O2 into it though, (that is considered the best way of doing it) but each will help.

So to answer your question, yes, it is a good idea, but there are other ways.

 

[James85]

Thanks for your answers guys. I usually stir untilly arm ja ready to fall off ghen change arms and repeat, now ill give it a shake for 5 minutes and see how i go. Don't worry bout the thread hijack Chunkious I learned something from it also

 

[pk.sax]

For a while I was simply rubber banding a battery operated milk frother with a bent wire to the hose delivering the wort into my fermenter. Worked quite well. Now that I switched to a carboy I might have to think up something fancier.

 

[Blitzer]

I notice Craftbrewer has air pumps listed though they haven't been in stock for a while. I assume this is just pumping air rather than pure C02 though that would still be fine, anyone know where else you can buy these air pumps?

 

[Yob]

aquarium shop, get an inline filter (or make one easy enough) from a reputable HBS.. it's what I currently use, allows me to turn on a faff about with other things for 10 minutes... easy as.

You can get an airstone as well, but IMO they are more trouble than they are worth.

 

[Black n Tan]

I have had no luck using an in line filter and an air stone. I initially purchased a small aquarium pump, with a 0.22 micron (?) filter and couldn't get any air out of the air stone. Bought a new stone because I had been handling it and the oils on your skin can block the stone. That didn't work either. The LHBS told me to get a more powerful pump, so I did and had the same issue. After a lot of shaking , splashing and all that business, I decided to go to oxygen. Someone mentioned to me that you often need to remove the in line filter to get air through the airstone. Just keep that in mind if you get no air flow. I was also told to turn the pump on before you place the stone in the wort to reduce the chance of it blocking. Anyway a few things to consider. If your in Melbourne I have a couple of near new aquarium pumps, very cheap.

 

[HBHB]

Aeration is important for the growth phase over the first 24 odd hrs post pitching. Sufficient oxygen in the wort will allow the yeast to drop enough pups into your wort to get the fermentation done effectively and without unwanted flavours developing.

Suffice to say that in the case of most beer styles, you can get sufficient oxygen dissolved in the wort by simply stirring vigorously for several minutes before pitching the yeast. For higher gravity worts, it's often worth while considering doing either a second aeration after about 12 hrs or direct injecting oxygen before pitching.

Most of the oxygen used with this method isn't going to remain dissolved in the wort and available to the yeast for that early phase and will simply be lost. This is mainly due to the relatively warmer temperatures of the wort (18-22 degrees or even higher).

The one thing that is a constant, is that if you don't aerate/oxygenate well before pitching, you probably won't get great results and the yeast will grudgingly slave away producing unwanted flavours in the process.

Once your beer is past the first 12-24 hrs post pitching, you don't want to be introducing any oxygen into the wort and indeed, it can end up with a poor result.

Keep in mind the warmer your wort is before pitching, the harder it is to get oxygen to stay in the wort during that aeration/oxygenation phase. Be guided by the instructions given by the company that propagates the yeast strain you're using. Every strain is different.

For the brewers who are considering direct injection of oxygen using the kits put together by the sponsoring businesses on here, especially on those big beers......go for it. Direct injection does lead to excellent results, rapid fermentation and lower FG's when you're looking for a drier finish.

If you can't/don't want to, then you'll still get great results, just with a lot more elbow grease, shaking and stirring.


Time for another IIPA.

 

[pk.sax]

No elbow grease involved in this one

 

[mmmyummybeer]

No elbow grease involved in this one

Got to love it. Another great aussie home brew build

Also Basic Brewing Radio did an interesting podcast on wort aeration at the national home brew conference. They noted that generally the higher the aeration the better cleaner flavoured beer. Also the more aeration the bigger the krausen was and the paint stirrer on a drill type method didn't work so well. Shake worked well though.

 

[jammer]

You can't over aerate by stirring....
8 ppm is best case.
An oxy set up let's you go up to 14ppm.
Recently bought one,
It's great, although takes a bit of tinkering to get the flow rate right.
No gauge on regulator, so a bit of fine tuning needed, but easy when you get it dialed in

 

[JasonP]

has anyone got a DO meter or ever tested their wort? They are expansive - always thought that they were $0000s but looks like you can get a Hanna DO meter for $500 which sounds suitable for homebrew use. Anyone use them care to share any advice?

 

[JasonP]

and another question....... if the starter is really well aerated, how well does the unfermentated wort have to be aerated?