# "Food grade". Yeast Nutriment vs. Miracle-Gro **URL:** \ **Category:** Factual Questions\ **Created:** [June 22, 2006, 5:24am UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683 "2006-06-22T05:24:06Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [June 22, 2006, 5:24am UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/1 "2006-06-22T05:24:06Z")
A friend of mine who’s getting into home brewing has noted the following: Yeast Nutriment is “food grade” ammonium nitrate. Miracle-Gro is (among other things) ammonium nitrate. He’s sure that the two are essentially the same on the supposition that anything that would hurt plants would also hurt us, and that the only difference is that YN has a “food grade” label (and a large markup) slapped onto it at the production plant. Can someone run down what it is that makes Miracle-Gro _not_ “food grade” and thus why it can’t be used in home brewing? ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [June 22, 2006, 12:21pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/2 "2006-06-22T12:21:15Z")
> [@Mathochist](#): > > Can someone run down what it is that makes Miracle-Gro _not_ “food grade” and thus why it can’t be used in home brewing? Listed ingredients for Miracle-Gro: 5.8% Ammoniacal Nitrogen • 9.2% Urea Nitrogen • 30% Available Phosphate • 15% Soluble Potash • 0.02% Boron • 0.07% Copper • 0.15% Iron • 0.05% Manganese • 0.005% Molybdenum • 0.06% Zinc Apart from whether all that stuff makes a palatable and safe brew, there’s the question of what sources (including animal matter) may be used to derive the fertilizer and how sterile the process is (i.e., a little bacterial contamination might be no problem as far as your plants are concerned, but potentially big trouble for your G.I. tract). Maybe it’s completely safe, but this is not an area in which I’d want to experiment. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 22, 2006, 1:16pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/3 "2006-06-22T13:16:04Z")
> [@Jackmannii](#): > > (i.e., a little bacterial contamination might be no problem as far as your plants are concerned, but potentially big trouble for your G.I. tract). I don’t think the bacteria would be a health issue since the yeast will make beer which will kill the bacteria, but you don’t want to introduce other micro-beasties into the mix. I guess you could boil up a small solution of Miracle Gro to kill them first. The yeast nutriants are just insainly expensive, I would wag it works out to perhaps a thousand dollars for a gallon, then again you only need only about 1 teaspoon/5 gal beer, but you know someone is making a buttload of money on this, which makes people search for alternatives. ---
**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\ **Post date:** [June 22, 2006, 4:53pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/4 "2006-06-22T16:53:04Z")
If you are home brewing beer, I will posit that adding additional nutrients for the yeast is unnecessary. Wort has plenty of the necessary nutrients for brewer’s yeast. If you are making a mead, then additional nutrients can be necessary. I have had success using a couple of crushed Flintstones vitamins. I wouldn’t use Miracle-Gro. ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [June 22, 2006, 9:58pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/5 "2006-06-22T21:58:52Z")
> [@August West](#): > > If you are home brewing beer, I will posit that adding additional nutrients for the yeast is unnecessary. Wort has plenty of the necessary nutrients for brewer’s yeast. > > If you are making a mead, then additional nutrients can be necessary. I have had success using a couple of crushed Flintstones vitamins. > > I wouldn’t use Miracle-Gro. I’ll pass on that vitamin suggestion. I don’t know what he’s making nowadays, but at some point he was making what he called a “cyser”, which he described as a cross between mead and cider. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [June 22, 2006, 10:05pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/6 "2006-06-22T22:05:13Z")
> [@kanicbird](#): > > The yeast nutriants are just insainly expensive, I would wag it works out to perhaps a thousand dollars for a gallon, then again you only need only about 1 teaspoon/5 gal beer, but you know someone is making a buttload of money on this, which makes people search for alternatives. I just looked up yeast nutrient on a half dozen homebrew websites, and they’re all selling it for less than $1 per ounce if you buy it 2oz at a time, it’s even less if you buy a pound. Pony up the $0.25 per 5gal batch, instead of dumping plant food in your beer. ---
**Author:** ![Excalibre](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Excalibre](https://boards.straightdope.com/u/Excalibre)\ **Post date:** [June 22, 2006, 10:31pm UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/7 "2006-06-22T22:31:49Z")
> [@Mathochist](#): > > I’ll pass on that vitamin suggestion. I don’t know what he’s making nowadays, but at some point he was making what he called a “cyser”, which he described as a cross between mead and cider. If you need a nitrogen source, why would Flintstones vitamins help? 😕 ---
**Author:** ![Grelby](https://avatars.discourse-cdn.com/v4/letter/g/a5b964/32.png) [@Grelby](https://boards.straightdope.com/u/Grelby)\ **Post date:** [June 23, 2006, 1:44am UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/8 "2006-06-23T01:44:49Z")
> [@Mathochist](#): > > He’s sure that the two are essentially the same on the supposition that anything that would hurt plants would also hurt us. Not to speak too unkindly of your friend, but this is an incredibly stupid assumption to make. Plants are an entirely separate kingdom of life. Given that plenty of animals, even other mammals, have entirely different tolerances for certain compounds (dogs and chocolate, anyone?) should be enough to make you think about the differences between what plants and humans can safely ingest. For example, many plants will happily take arsenic up in quantities that would kill humans. Furthermore, as another poster has mentioned, there are enormous differences in processing, purifying and quality control between plant products and food grade items. Go give your friend a big dope slap on the back of the head, and tell him not to make guesses about something that people are going to be drinking (and drinking in large quantities, if he does it right). ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [June 23, 2006, 3:28am UTC](https://boards.straightdope.com/t/food-grade-yeast-nutriment-vs-miracle-gro/361683/9 "2006-06-23T03:28:45Z")
> [@Grelby](#): > > Not to speak too unkindly of your friend, but this is an incredibly stupid assumption to make. My exact words: “But… you aren’t _that_ dumb”