|420 Special Wheat And East Coast Yeast ECY12 - Old Newark Beer™|
Truth be told I started adding yeast nutrients to the wort boil at the same time I began using pure oxygen to prepare my wort for pitching yeast. I now add both a capsule of Servomyces nutritional yeast supplement and half a teaspoon of yeast nutrient to the end of all my wort boils to provide the yeast with a rich blend of sugars and minerals during fermentation. Maybe it's the combination of pitching, at the time of this post a fourth generation two liter starter of ECY-12 yeast at high krausen, adding yeast nutrients to the boil and then oxygenating the wort prior to pitching the yeast but there is a very noticeable difference in the quality of the finished beer now.
Additional information: Yeast Nutrients Make Better Beer by Christopher White, Ph.D
|Attenuation Chart (Courtesy of White Labs)|
For one thing the pitched yeast lag time has increased by about 20-30%, I don't notice much activity in the airlock for at least 18-24 hours but the beer's final gravity is finishing several points lower than it used to in prior batches fermented without oxygenation or nutritional supplements. Using aeration you can get at the very most 8ppm of oxygen into your wort by vigorously shaking your fermentor for a minute or using an aquarium pump, HEPA filter and air stone for at least five minutes.
|Rapidly Cool Full Wort Boils To Pitching Temperature|
Either of these methods creates a lot of wort foaming that can lead to issues with overflowing fermentors, head retention and lacing in your finished beer as well as increasing the risk of contamination. I use a 2 micron stainless steel diffuser and run enough pure oxygen through it to form a stream of very fine bubbles and I let it run for a full minute before pitching my yeast starter. At this rate flow rate, using the chart above as a guide, I can estimate that I am putting about 9ppm of dissolved oxygen into my wort which is the sweet spot for the beers I've been brewing.
|Higher Yeast Production With Nutrients|
The most notable change is in the taste and flavor of the beer now each sip tastes very clean, I mean there are no distracting off flavors so every ingredient you put in the kettle comes through clearly in the finished beer. I've been focusing mostly on my 420 Special Wheat and Screwer In The Rye recipes the past several months and since improving my yeast preparation as I have described earlier they have both developed an unmistakable clean flavor and aroma that leaves a really nice taste in your mouth after each glass.
|Control Fermentation Temperature For Better Beer|
|Collecting Washed Yeast After Kegging The Beer|
I made the decision to just bite the bullet and go all out to treat my yeast the best I could. I wanted to find out for myself exactly how much of a real difference added nutrients and oxygen would make and I was pleasantly surprised. If you have been considering making the move to pure oxygen do it you won't be disappointed.