Making nutritional yeast in large quantities?

[zhai]

Hi, I'm new to fermenting and brewing, and one of the things I would like to find out is whether it would be possible to make large quantities of yeast to dry and eat as a nutritional supplement. I've looked around, but I haven't been able to find a "recipe" that fits my needs completely, or probably I just don't have enough knowledge to assess whether existing recipes would fit this goal. E.g., most of the recipes add flour, and I'd like to avoid that.

I'm buying it at the moment and using relatively large amounts of it, so I'm thinking that if I could make it myself at an acceptable quality, and also get a bunch of CO2 for my indoor herb garden at the same time, that would be very nice!

I imagine one of the challenges would be to avoid getting all kinds of nasties into the yeast?

I'd like to grow the yeast using molasses (animal feed quality), so my current "recipe suggestion" looks like this:

water
molasses
bread yeast
tomato paste
aeration with an airstone connected to an aquarium pump

I'm guessing I should also measure the pH and keep it around 5.5?

Am I on the right track here, or should I do something completely different?

[raketemensch]

Be careful with your intake:

http://www.npr.org/sections/thesalt/201 ... n-your-gut" onclick="window.open(this.href);return false;" rel="nofollow

[FuelMaker]

I've considered it myself - mainly with an eye towards using it as a emergency food supply.

I'm certainly no fermentation expert but what you have in mind for nutrients sounds good, I would add a post-fermentation step though: washing. Wash the yeast to remove all the non-fermentables out of it and then dry and bake it. The yeast needs to be killed before consumption or you're going to have tummy problems.

A few months ago I made a mistake with one of my test ferments and forgot to turn off the air pump so instead of running for 30 mins it ran for 5 days. I didn't make any alcohol at all, but more than half of the 5 gallon bucket I was using was full of yeast. And it smelled good too. That's when the thought hit me "I could eat this in a pinch if I had to".

[Hillbilly Popstar]

Seems the sugar, starches, minerals and nutrients would make better "emergency food supplies" than the yeast themselves.

[zhai]

raketemensch:

Don't worry, I'm going to kill the yeast off completely before eating it.

FuelMaker:

Washing does indeed sound like an essential step. Too funny about your accidental yeast production!

Hillbilly Popstar:

Well for me it's not really emergency food, however I would not like to have to live on molasses.


I had started a portion of yeast-breeding, however I found out that the molasses I used was not from cane, as I thought, but from beet. That didn't work very well - hardly any yeast was produced. It did make a lot of foam, but I can't figure out where the sugar went, as it didn't taste like there was any alcohol present either?

So now I've got a new portion going, this time using cane molasses. We'll see how it goes!

[shadylane]

$5 will get 2 pounds of yeast at Sams Club.

[skow69]

Here is a link you might find useful. http://www.dakotayeast.com/yeast_production.html

[Bagasso]

Seems the sugar, starches, minerals and nutrients would make better "emergency food supplies" than the yeast themselves.

That list is missing proteins and that is what the wee beasties are converting some of those sugars into.

[Hillbilly Popstar]

Your body does that too, does it not?

[Bagasso]

Your body does that too, does it not?

No, if it did vegetarians wouldn't need to worry about finding non-animal sources of protein.

[Hillbilly Popstar]

That makes sense.

[Bagasso]

That makes sense.

Vegans have it worst because they can't (choose not to) eat any animal products so things like milk, cheese, eggs or gelatine (made from bones) is off the table.

A big thing for them is nutritional yeast. I called them beasties but in fact they are a mold, which means that they are a plant, and they are a complete protein, which is important.

A serving also provides 9 g of protein and is a complete protein, providing all nine amino acids the human body cannot produce.

For the OP, you can't have your cake and eat it too. The key to have yeast reproduce is to provide oxygen but this keeps them from producing ethanol and CO2 so, an air pump in the wash will get you more yeast, less "nasties, but nothing or very little to drink or for your herb garden.

Just my 2 bits.

[zhai]

Bagasso:

I'm confused about your statement that yeast does not make CO2 while reproducing.

When oxygen is not present, the yeast does anaerobic fermentation which make ethanol and CO2:

C6H12O6 -> 2C2H5OH + 2CO2

When oxygen is present, the yeast does aerobic respiration:

C6H12O6 + 6O2 -> 6CO2 + 6H2O

So it follows that anaerobically, yeast makes 0.5 g CO2 per gram of sugar, while aerobically, it makes 3 times as much, 1.5g, so I should get lots of yeast and lots of CO2, unless I have missed something?

[FuelMaker]

From what I understand, store-bought "nutritional yeast" is fortified with vitamin B12 as that is the one glaring lack in a vegan diet.

And yes, yeast do produce CO2 with aerobic fermentation, just not ethanol.

[Bagasso]

So it follows that anaerobically, yeast makes 0.5 g CO2 per gram of sugar, while aerobically, it makes 3 times as much, 1.5g, so I should get lots of yeast and lots of CO2, unless I have missed something?

Sorry, I was not really sure, but I guess I was thinking that CO2 was greater during the creation of ethanol since during the lag phase (yeast growth) there is little activity in an airlock.

Faulty observation on my part, without actually looking it up.