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?
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.
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 : Oxygenation Kit 2.0
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.
*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.
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”).
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.
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.
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.
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.
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.
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.
I just use a siphon sprayer 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.
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.