So I have some very very old Fermax Yeast Nutrient. Apparently this contains “diammonium phosphate, dipotassium phosphate, magnesium sulfate and autolyzed yeast.” It’s gotten old and clumpy and I’ve decided to throw it out and buy some new product, and my LHBS had something very different that seems to be (I think) diammonium phosphate only.
So is one better than the other? What’s the difference? Can I use them in the same amounts? I am using this stuff for yeast starters made from DME – I don’t typically add nutrient to finished wort. 6 oz DME, 2 quarts water, 1/4 tsp nutrient.
DAP is solely a nitrogen supplement. It doesn’t contain any of the other nutrients that yeast need (zinc, lipids, etc). You’re better off with something more complete than straight-up DAP.
I use the wyeast stuff. Hard to say if it works becuase ive used it for every batch but my first. I will say my beers start fermenting within a few hours and taste great so i will continue to use it. I use 0.5 tsp per 5 gallon batch and a pinch in starter.
Salt doesn’t go bad. I would not have thrown out the old stuff. It had more of the vital nutrients. That being said, so does malt. I rarely add yeast nutrients.
The only yeast nutrient I’ve ever used is around 2/3 to 1/2 of the slurry saved from my last ferment… i goes into the boil, as per what apparently is (or was) the standard procedure at Fuller’s.
The rest of the saved slurry is used in the ferment itself.
Well I haven’t thrown it out yet. This stuff seems to contain autolyzed yeast, and it seems like it’s been exposed to a lot of humidity so that it’s sticky and clumpy, no longer a powder. Kinda tough to measure out 3/4 tsp. Still I guess I’ll continue to use it until I can get some more. I’m disappointed that the stuff I bought at the LHBS seems to be inadequate. I find I’m relying on them less and less for anything.
The yeast is a source of amino acids and I don’t think they’d go bad real fast. Maybe the B vitamins would though. Certainly the zinc and DAP would be OK.
I do use a nutrient like Fermax that has the blend of various nutrients. I think it can be beneficial when you make a wheat beer, and some yeasts are more needy when it comes to nitrogen.
