LD Carlson 'Yeast Nutrient' may be as much as 5/6 urea and provide north of 500 YAN at package dosing

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dmw_chef

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Urea has been banned in US commercial winemaking for 30ish years because it can react with ethanol to produce ethyl carbomate, a known carcinogen. LD Carlson has long been secretive about their exact formulation. A buddy of mine published some preliminary results from experiment whos results seem to indicate that the 'Yeast Nutrient' product may be 5 parts urea to 1 part DAP.



This revelation rocked my world just a little bit. The conventional wisdom I've always heard is to treat LD Carlson 'Yeast Nutrient' as an equivalent to DAP. One of the commenters on the post, balathustrius of Advanced Nutrients in Meadmaking fame speculates that LD Carlson 'Yeast Nutrient' may contribute almost 500 PPM YAN at a 1g/L dosing. The same dosing of DAP contributes only 210 PPM. The package dosing is even higher than that.

If true, this should be a huge scandal in my opinion. If anyone has the ability to do a YAN assay, I'd be in your debt if you could do one of a solution dosed with 1g/L 'Yeast Nutrient'
 
ALL chemical reagents have a material data safety sheet available. Have you looked at the MDSS ? LD Carlson should give it out on request or a link to it.

(I haven’t run this test method and would need to visit the old company library/ a university library to look it up in standard methods)
 
Urea has been banned in US commercial winemaking for 30ish years because it can react with ethanol to produce ethyl carbomate, a known carcinogen. LD Carlson has long been secretive about their exact formulation. A buddy of mine published some preliminary results from experiment whos results seem to indicate that the 'Yeast Nutrient' product may be 5 parts urea to 1 part DAP.



This revelation rocked my world just a little bit. The conventional wisdom I've always heard is to treat LD Carlson 'Yeast Nutrient' as an equivalent to DAP. One of the commenters on the post, balathustrius of Advanced Nutrients in Meadmaking fame speculates that LD Carlson 'Yeast Nutrient' may contribute almost 500 PPM YAN at a 1g/L dosing. The same dosing of DAP contributes only 210 PPM. The package dosing is even higher than that.

If true, this should be a huge scandal in my opinion. If anyone has the ability to do a YAN assay, I'd be in your debt if you could do one of a solution dosed with 1g/L 'Yeast Nutrient'

Everything I see from recently and years back shows LD Carlson 'yeast nutrient' is DAP and urea. Several online sellers actually indicate that on the listing, and apparently LD Carlson wholesale site links to separate MSDS for urea and diammonium phosphate, or did at the time. Composition etc. has been discussed quite a bit on various forums, but that has fallen into historic postings. Maybe time for that to come to the top again for those that just buy what is sold to homebrewers, winemakers, etc.
 
ALL chemical reagents have a material data safety sheet available. Have you looked at the MDSS ? LD Carlson should give it out on request or a link to it.

(I haven’t run this test method and would need to visit the old company library/ a university library to look it up in standard methods)

They're under no obligation to give them to customers. And they won't. I've asked.
 
Just saw this on Reddit's homebrewing forum (I think it started in Mead and is probably up in winemaking forum now too), was coming to post it here. Fortunately, I had the good sense to first search for Urea and so I avoided the dreaded double post. That is all I have. Glad that I don't use yeast nutrients in my homebrew, and the ones I bought for wine making (Go Ferm and Fermaid K) do not seem to be on the naughty list, and I was just able to pull up detailed info on both products on Scott Lab's website which is reassuring.
 
The company that sells it to you should be expected to provide MSDS if asked, wholesalers no. Same document, different responsible party.

The MSDS is an OSHA regulation. Companies are only obligated to supply a MSDS to business customers, whose employees have to handle them in one way or another as part of their employment. LD Carlson has a legal requirement to provide a MSDS for 'Yeast Nutrient' to Midwest Supplies or your LHBS. They have no obligation to provide a MSDS to individual customers. Your LHBS may be able to get one for us if asked.
 
I've been really confused here, but not really surprised at lack of thought. If a person only wanted what was allowed by the TTB, they should read and follow those regs. Anyone who actually bought the LD Carlson 'yeast nutrient' product can see that it contains urea and DAP, had that on jars and has that on zip bags. DAP does not contain anything else- if labeled as DAP. Any supplier, same thing. Any other supplier's yeast nutrient will say what is in it, roughly. Almost no company will say exact formulas on their package- that is proprietary. Anyone who researched would see that home fermentors can use whatever they want and can buy. There are lots of things people do to food and drink that can't be sold, but you can do what you want to your own. Food-grade urea is 'Generally Recognized as Safe'. Why is it that LD Carlson should be shamed that urea is in/is most of their product?
 
It says right on the package that it contains urea:

But this one claims to be 99% DAP on Amazon: Amazon.com: Diammonium Phosphate 99% 1 Lb Bag : Grocery & Gourmet Food So maybe the key point is to buy DAP rather than "Yeast Nutrient"

I do not disagree. They do say it contains urea. The Conventional Wisdom in almost the entire homebrew community has been to treat it like DAP for the purposes of YAN supplementation. On paper, it supplies more than twice the YAN gram for gram as pure DAP.

The package dose, on paper, supplies more than 500 YAN, most of which is from the urea, more than enough that a substantial amount remains in your wine after fermentation. LD Carlson will tell you that doesn't matter, it needs to be heated to convert into ethyl carbonate, but that's not true.

Again: I stipulate that they are upfront that it contains urea. The scandal here is 1) the proportions, 2) the fact that they are selling an ingredient that's been banned in commercial winemaking for 30 years for good reason, 3) their package dosing is such that it virtually guarantees there will be excess urea *from the nutrient* after fermentation; that's not including that which is present from fermentation.

I'm hoping that I'll have actual YAN analysis by a professional lab in the next week or two.
 
Urea has been banned in US commercial winemaking for 30ish years because it can react with ethanol to produce ethyl carbomate, a known carcinogen. LD Carlson has long been secretive about their exact formulation. A buddy of mine published some preliminary results from experiment whos results seem to indicate that the 'Yeast Nutrient' product may be 5 parts urea to 1 part DAP.



This revelation rocked my world just a little bit. The conventional wisdom I've always heard is to treat LD Carlson 'Yeast Nutrient' as an equivalent to DAP. One of the commenters on the post, balathustrius of Advanced Nutrients in Meadmaking fame speculates that LD Carlson 'Yeast Nutrient' may contribute almost 500 PPM YAN at a 1g/L dosing. The same dosing of DAP contributes only 210 PPM. The package dosing is even higher than that.

If true, this should be a huge scandal in my opinion. If anyone has the ability to do a YAN assay, I'd be in your debt if you could do one of a solution dosed with 1g/L 'Yeast Nutrient'

I am very interested in any further results of "yeast nutrient" analysis. Has any progress been made?
 
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