Thanks Ill have to give that one a listen. I think its just a matter of calculating the equivalent YAN in Fermaid-O compared to Fermaid K and dosing accordingly no?
Well that's where it gets a little confusing to me. (I am new to the idea of YAN and have done some internet reading so none of what follows is my knowledge or experience but information from the interweb collective.) This is what I have pieced together:
Yes the Fermaid-O has a YAN contribution that is a bit less than the Fermaid-K. Fermaid-K essentially provides the YAN with DAP plus added nutrients and vitamins. The reason people use Fermaid-K and DAP together is because if you use all Fermaid-K, especially in a mead which had an initial YAN value of dang near zero, you are adding over the legal limit (form a commercial perspective and likely not a good idea in general) of a particular vitamin (thiamin?).
Unlike Fermaid-K which adds inorganic nitrogen via DAP, Fermaid-O provides organic nitrogen and is better for the yeast. The layman analogy is the DAP is like pure sugar for energy and organic nitrogen is more of a healthy balanced diet of the nitrogen. Additionally, the Fermaid-O can be added after the 1/2 way point in fermentation as the yeast can still uptake it and make use of other things in the form its in (sterols I think). People also say because of how it is delivered to the yeast, fermentation is more constant (no big spikes where the mead gets hot) and it actually finishes a little faster and more completely. However, while the Fermaid-O is a "healthier" form of nitrogen, the product does not have the other added vitamins and nutrients that Fermaid-K has.
I the podcast and a couple of places online, it was said that there was a noticeable flavor difference between the two products and that the Fermaid-O was better for aroma retention/development (???).
I think the staggered addition is still the only way to go, but I am wondering if all Fermaid-O may be a better new way to go or Fermaid-K/DAP in the earliest stage to provide the vitamins/other nutrients and Fermaid-O for the rest, or what.
I guess the little bit of knowledge has left me with more questions than answers. Again, this all being that I dug up on the web.