My understanding is:
Keep away from Urea in fermentation - it is illegal in New Zealand to have
any traces of Urea in any shape or form, due to carcinogenic possibilities.
Urea is mainly used because it produces a very quick "clean" ferment.
Apparently, it is not illegal in some European/Scandinavian countries -
Sweden is one country that produces Turbo yeasts with Urea as one of the
base products, although it is possible to purchase 'urea-free' Turbo yeasts
from major suppliers, but special minimum runs are 1000 packets of turbo
yeast per purchase order! Now, that is quite a bit of distilled spirit eh?
There is an anomaly here, and I was of the belief that many European
countries had much stricter rules than New Zealand - but apparently not!
MILL-FORD LODGE HOMEBREW SHOP
From: Ackland, Tony (CALNZAS) <Tony.Ackland@...
Subject: [Distillers] Urea & nutrients
Date: Thursday, 28 September 2000 12:40
I've just been going through some rec.crafts.brewing posts, and found that
may have been put wrong about using urea as a possible yeast nutrient.
try and dig around a little more to substantiate the claim that its harmful
(I've never heard of ethyl carbamates before).
********* SNIP **************
Date: Thu, 24 Aug 2000 14:37:10 -0400
From: "Pannicke, Glen A." <glen_pannicke@...
>Whilst in an investigational study involving yeast nutrients, ...
> "Please inform this brewer that urea based products are banned
>throughout most of the World for beverage alcohol.
>They produce ethyl carbamates which are CARCINOGENIC.
*********** SNIP ***********
to which a bit later this was the reply re what various nutrients might
contain (eg is there any urea in them ?)
*********** SNIP ***********
Subject: Yeast Nutrient Composition
From: Mark Evenson <wine-hop@...
Date: Mon, 01 Dec 1997 13:04:56 -0800
For the person with the question on chemical composition of yeast
nutrient: Three of the largest homebrew/winemaking wholesale suppliers
use varying formulas in their "house brand". Your local homebrew shop
should be able to identify their source (especially if you're willing to
share your info).
L.D. Carlson (Kent, OH) food-grade urea and diammonium phosphate; white
in color with fairly large, rounded granules
G.W. Kent (Ann Arbor, MI) these folks have two types
- -"Nutrient" diammonium phosphate; white, small crystals similar in size
to sugar crystals (though more long than square)
- -"Energizer" diammonium phosphate, yeast hulls, magnesium sulfate,
thiamine, folic acid, niacin, calcium pantothenate; small tan grains
with some white particles visible. I believe this is from Lalvin.
Crosby & Baker (Westmort, MA) Fermax(TM) contains diammonium phosphate,
dipotassium phosphate, magnesium sulfate, autolyzed yeast.
also DLB Vineyards (Westlake, OH) diammonium phosphate; white grains.
Sorry for the delay in responding; I wanted to check with the suppliers
listed above to get official permission to post this info. Nobody said
"no" although if you want more detailed info (i.e., what percentage of
each chemical) you should contact your local homebrew shop.
To support one of my comments of 11-22-97, I haven't found yeast
nutrient to be helpful in my fermentations when pitching *large*
quantities of yeast (5 gr dried wine yeast/gallon). My starting SG
ranges from 1.090 to 1.100, and ferments to dryness (0.996 to 1.002) in
about 2 1/2 to 3 weeks. When I did use 1 tsp nutrient in a 6 gal batch
pitching 5 gr yeast/gallon, fermentation time was still 3 weeks, and
left a strong chemical flavor (metallic, to my tastebuds). I'd like to
stress that I've not done side-by-side tests with yeast hulls or bee
pollen, so I don't know how these behave. After the "test batch" came up
with such a strong flavor of nutrient, I swore off nutrient entirely...
Anyway, that's my nickel's worth.
Thanks for providing the forum for discussion!
Anne T c/o wine-hop@...