Sunday, September 05, 2010

New Batch ingredients - extra info

Ok, so this morning, its obviously finished it's "lag phase". So, because I wasn't sure about how to work out it's exact nutrient requirements, I posted a question at Gotmead and "Medsen Fey" was kind enough to post this response.

"I really like the approach Wayneb describes in This Post. For D21, you have a medium nutrient requiring yeast, and you are starting at 28 Brix which is moderately high. I'd probably shoot for around 350 ppm YAN. There is a YAN calculator that has been put together, but it generates numbers that are quite high, and even I get a little timid about adding that much. Of course, I used to be timid about adding the amount hightest recommends, and now I find that isn't enough in most cases.

In any case:
1 gram of DAP per Imperial Gallon gives 46 ppm YAN
1 gram of Fermaid K per Imperial Gallon gives about 22 ppm YAN

Typically, I like a 2/3 Fermaid K, 1/3 DAP mix to ensure plenty of micronutrients and yeast hulls. So using 8 grams of Fermaid K and 4 grams of DAP would give about 360 ppm YAN. The honey itself may provide 10-20 ppm.  That is the way I approach nutrient additions."
So I've followed that guidance (not that I understand how to use the YAN (Yeast Assimilative Nitrogen) calculator, so initially it's had 4 grammes of FermaidK and 2 grammes of  the Ritchies yeast nutrient (Diammonium Phosphate and something else that I forget the name of - but I'll include it when I've looked it up).

I'm quite glad that I took a pint out of it and then when it was time to give it a stir to aerate it, that I stood it in the sink as I got an excellent foam eruption out of it. The picture shows it after it's settled down again. I'll check the gravity before I aerate it this evening to see how it's getting on, the intention being that I want it to hit the 1/3 rd sugar break before adding the second half of the nutrients.


1 comment:

Aristaeus said...

Academic my good Fatbloke...academic! He thus protest, now he is MASTER!