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General Category => Yeast and Fermentation => Topic started by: pmallory on November 15, 2010, 04:18:59 AM

Title: Oxygenating Wort
Post by: pmallory on November 15, 2010, 04:18:59 AM
I feel that I have underestimated how important it is to oxygenate my wort and starters to achieve the best conditions for yeast. I am curious what methods have worked for other people. I have heard of a stir plate and am curious if they work well and whats the cheapest way to get one. I've also seen people just slosh their beer around in a carboy, or splashing your wort into the fermenter. Does anybody else have any suggestions for oxygenating wort for the fermenter or the starter?
Title: Re: Oxygenating Wort
Post by: chezteth on November 15, 2010, 04:46:55 AM
Oxygenating your wort is very important for fermentation.  Yeast growth requires oxygen for proper cell division.  I just slosh the wort in the carboy to aerate.  It seems to work well.  Others use pure oxygen for aerating.  I guess it, partially, comes down to personal preference.  Hope this helps.

Happy Brewing
Brandon
Title: Re: Oxygenating Wort
Post by: rbclay on November 15, 2010, 05:57:02 AM
It is relatively simple and not too expensive to properly oxygenate your starters and wort. Most LHBS' sell the adapter for the red O2 tanks. Like this : http://www.northernbrewer.com/brewing/brewing-equipment/fermenting-equipment/aeration/economy-oxygenation-kit-w-regulator-and-stone.html
You have to get the tanks at your local hardware store for $10.  For me that's worth it. A little red tank lasts probably 10 batches for me. I time the length I send O2 into my starters and wort. 30 seconds for starters, 2 minutes for 5G of wort. Not too scientific, but I have seen very good results and can repeat the same process each time. The next step up would be to get a bigger, refillable O2 tank and a regulator. Not worth it for me, but it would be cool!
For me I never bothered to try to aerate me wort. Yeast don't want just "air", they want oxygen. A stir plate would be cool also. I've seen plans that don't look too difficult to make. I have had good success with my "little" 500-800ml starters with no stir plate, just the occasional swirl by hand in  the 12 or so hours they are going.
Title: Re: Oxygenating Wort
Post by: tumarkin on November 15, 2010, 12:01:26 PM
You have to get the tanks at your local hardware store for $10. 

*1 on the small red O2 tanks & a sintered stone. But no $10 refills for me, for a while anyway. One of the local Home Depots had a shopping cart full up by the front of the store..... on sale for a $1 each. Got me 6 of 'em. Happy day.
Title: Re: Oxygenating Wort
Post by: hopfenundmalz on November 15, 2010, 01:25:34 PM
For me I never bothered to try to aerate me wort. Yeast don't want just "air", they want oxygen. A stir plate would be cool also.

Some strains of yeast require more O2 than others.  Sierra Nevada uses sterile filtered air as the O2 source.  More flocculant yeast usually require a higher dissolved O2 level, so you need an O2 tank and stone to get to the higher levels (this is covered in "Yeast").

Stir plates are ubercool. 
Title: Re: Oxygenating Wort
Post by: bluesman on November 15, 2010, 02:13:23 PM
I use a mix-stir rod that is attached to a drill motor.

(http://www.highgravitybrew.com/productcart/pc/catalog/mix-stir-1_2109_detail.jpg)

This method incorporates O2 from the atmospherere into the wort. It's easy to use and produces good results.
Title: Re: Oxygenating Wort
Post by: Tim McManus on November 15, 2010, 03:45:38 PM
We use an O2 tank and stone.  It makes a considerable difference in the quality of your beer.

We also started using a stir plate.

http://www.northernbrewer.com/default/northern-brewer-stir-plate.html
http://www.northernbrewer.com/default/2000-ml-yeast-starter-kit.html

With a properly made starter we can get a krausen on the wort in about 6 hours.  The cost of the stir plate and the starter kit was about $100.  However, in the past we would make 2 gallons of starter for high gravity beers using 2# of DME.  Now we make 1.5L of starter with 1.5 cups of DME for the same high gravity batches.  It saves us approximately $20 per batch, so in the long run it's a really good thing.
Title: Re: Oxygenating Wort
Post by: denny on November 15, 2010, 03:59:32 PM
I've used a MixStir for the last 10 years and it works great.  As far as I can tell when compared to friends who use an O2 system, I'd have to say the MixStir is as effective in the results it produces.  I recently started using a stir plate for starters and I immediately saw benefits form it.
Title: Re: Oxygenating Wort
Post by: gordonstrong on November 15, 2010, 06:50:32 PM
Stir plate for starters, Mix Stir for normal batches, pure O2 through a sintered stone for big batches.
Title: Re: Oxygenating Wort
Post by: markaberrant on November 16, 2010, 04:58:57 AM
Mix Stir for normal batches, pure O2 through a sintered stone for big batches.

Just curious, why the difference?  I use pure O2 for all batches, more for big 'uns.
Title: Re: Oxygenating Wort
Post by: pyrite on November 16, 2010, 05:42:51 AM
For all my brews I place the yeast starters on the stir plate.  Then as soon as I inoculate the wort with the yeast, I add a dose of  pure oxygen through a carb stone.  If it's a high gravity brew (9% - 12%) not only am I adding a high yeast count, but I come back twelve hours later and add some more pure oxygen through a carb stone.  
(http://i205.photobucket.com/albums/bb218/brewbock/Photo-0082.jpg)
Title: Re: Oxygenating Wort
Post by: pmallory on November 16, 2010, 06:27:20 AM
What is a MixStir?
Title: Re: Oxygenating Wort
Post by: jeffy on November 16, 2010, 12:09:08 PM
What is a MixStir?
Bluesman has a photo of it about six posts up.
Title: Re: Oxygenating Wort
Post by: bluesssman on November 16, 2010, 05:02:32 PM
For all my brews I place the yeast starters on the stir plate.  Then as soon as I inoculate the wort with the yeast, I add a dose of  pure oxygen through a carb stone.  

I too use a stir plate and I built an inline 02 aerator which goes between my chiller and the fermenter.
Title: Re: Oxygenating Wort
Post by: tom on November 16, 2010, 06:05:49 PM
Mix Stir for normal batches, pure O2 through a sintered stone for big batches.

Just curious, why the difference?  I use pure O2 for all batches, more for big 'uns.
Shaking the bejeesus out of a regular strength batch of ale is enough oxygenation for the yeast. For lagers and high gravity ales shaking with air won't get enough oxygen into solution for the yeast.
Title: Re: Oxygenating Wort
Post by: johnf on November 16, 2010, 06:08:54 PM
Mix Stir for normal batches, pure O2 through a sintered stone for big batches.

Just curious, why the difference?  I use pure O2 for all batches, more for big 'uns.
Shaking the bejeesus out of a regular strength batch of ale is enough oxygenation for the yeast. For lagers and high gravity ales shaking with air won't get enough oxygen into solution for the yeast.

Well in Gordon's case getting out the drill and the mix-stir (and sanitizing the latter) is about as involved as getting out the sintered stone and 02 tank.

My guess is that with the mix-stir you can reliably saturate with air with for normal gravity ales is going to be 8 ppm and for normal gravity lagers maybe closer to 10 ppm. If that's about exactly what Gordon wants, saturation with air takes out the guesswork involved with 02 assuming no DO meter is available.
Title: Re: Oxygenating Wort
Post by: gordonstrong on November 16, 2010, 06:46:45 PM
Oxygen is a consumable.  It costs money and I have to go to the hardware store to get it.  The Mix-Stir just uses battery charge on a rechargeable drill.  It's also easier to clean the mix-stir (marginally).  So I use the Mix-Stir when possible.

I use more O2 on bigger batches because I really want to encourage the best growth environment for the yeast.

There's no problem with using O2 on normal batches.  It is just faster and less hassle for me to use the Mix-Stir.

I don't have DO measuring equipment so I don't know the difference between the methods.  I just found something that reliably works, so that's what I do.

Basically, I try to optimize my process to the point where I can use easier indirect measurements that I know will give me desired results.  I know I need to run my O2 full blast for a minute.  I know I need to use the Mix-Stir on a certain setting for a certain time.  I don't need to measure DO levels because I know following my process for these times will give me what I want.

Sort of like I don't measure my water-to-grist ratio; I do it until it looks right. 
Title: Re: Oxygenating Wort
Post by: ipaguy on November 17, 2010, 01:51:55 AM
I just use a siphon sprayer http://www.midwestsupplies.com/siphon-sprayer.html (http://www.midwestsupplies.com/siphon-sprayer.html) when transferring to my fermenter.  I think that one thing that helps me out is that I get my wort quite cool before siphoning, around 66-68F.  Oxygen is a lot more soluble in cooler liquid.  Sure, the yeast would grow a little faster if I pitched at 70-80F, but so would any nasty bugs.  Never had any problems with this method, even with high gravity beers.
Title: Re: Oxygenating Wort
Post by: ajk on November 17, 2010, 03:07:31 PM
I dump from bucket to bucket from waist height 8 times.  I've heard this method attributed to George Fix but can't find a direct citation.  I've used a MixStir with comparable results, but I find the extra bucket easier to clean.
Title: Re: Oxygenating Wort
Post by: bluesman on November 17, 2010, 05:44:23 PM
I dump from bucket to bucket from waist height 8 times.  I've heard this method attributed to George Fix but can't find a direct citation.  I've used a MixStir with comparable results, but I find the extra bucket easier to clean.

I know some homebrewers that employ this method with good results. In a pinch, I plan to use this method as well.
Title: Re: Oxygenating Wort
Post by: pmallory on November 27, 2010, 07:54:11 PM
For all my brews I place the yeast starters on the stir plate.  Then as soon as I inoculate the wort with the yeast, I add a dose of  pure oxygen through a carb stone.  If it's a high gravity brew (9% - 12%) not only am I adding a high yeast count, but I come back twelve hours later and add some more pure oxygen through a carb stone.   
(http://i205.photobucket.com/albums/bb218/brewbock/Photo-0082.jpg)


Is there a point when you shouldn't add more oxygen to the fermentation? Won't oxygen at a certain point create vinegar flavors? Or could you just keep adding oxygen to the fermentation? I am guessing some commercial breweries add oxygen through the fermentation.
Title: Re: Oxygenating Wort
Post by: tschmidlin on November 28, 2010, 06:43:33 AM
Is there a point when you shouldn't add more oxygen to the fermentation? Won't oxygen at a certain point create vinegar flavors? Or could you just keep adding oxygen to the fermentation? I am guessing some commercial breweries add oxygen through the fermentation.
The main reason to stop adding oxygen is to prevent oxidizing the beer - it doesn't taste like vinegar though, unless you have acetobacter in there.  Commercial brewers don't add oxygen throughout the fermentation, but some add additional O2 early in fermentation for really strong beers to help the yeast along.