Is it safe to heat active dry yeast to make a substitute for nutritional yeast?
Nutritional Yeast isn't available at my location so i'm looking for alternatives.
While searching Seasoned Advice i've found this question How can I make nutritional yeast?. But i don't want exactly to grow nutritional yeast. It's too difficult to it and i need something more practical and less risky in terms of sterelization.
So i've came across this page. Basically it says i can use active dry yeast and toast it to make something that tastes like nutritional yeast. In this The Fresh Loaf post this heating the yeast technique is also mentioned.
Well, i did tried it at home and the result was very very tasty! First time i made it i've dropped a little yeast in a cup with water and sugar and it didn't started fermenting, but the second time i've tried it was still alive.
- There is any way to make sure that all the yeast is uniformly dead?
- Even if manage to kill all the yeast, let's say, by heating in the oven, is it still safe to eat it? I've read a lot of disquieting stuff on the web about yeast and botulism. (but there might be other factors to consider)
- (I must use Saccharomyces cerevisiae as the main ingredient because i want something similar in terms of protein content (about 45g on 100g of yeast)
(This is a duplicate of a question i've asked on Seasoned Advice. But in this forum members are probably more experienced with the subject)
Use boiling water, that should do it.
2) still safe to eat? Yes but remember the golden rule... Too much of anything is not a good thing. Check out the purine content of dead yeast and compare to other foods. A little is fine but I wouldn't go replacing my daily protein quota with yeast protein. Especially if gout runs in you family or you are prone to it.
Thanks for you answer!
1) About Purine
I already eat about 20~30g of brewers yeast daily. It's not really a replacement. This should give around 9~13g of protein, which is just a good extra. According to this table that should give between 363 and 543 of Total Purines in mg uric acid/100 g (Average). Currently i'm not that worried because i'm vegan and gout is most linked with animal food, mainly meat. Even vegetables of moderate levels of purine as beans are usually considered gout-friendly. So yeast is probably the only food high in purines in my diet, but i do want to stay on the safe side, so i guess it's time to search for maximum levels of purine on a diet. Thanks a lot for pointing that out :)
What made me happy is that i've noticed that Baker's Yeast contains less than half that purine levels of brewers yeast, which means i could eat even more and worry less! Plus it doesn't taste bitter. I do like brewer's yeast bitterness, but it's not as versatile as nutritional yeast. Plus i simply like nutritional yeast better :)
So in terms of purine i guess Baker's Yeast is as much safe as Nutritional Yeast.
Or maybe i'm forgetting something?
2) about Killing yeast
I've noticed you've replied to the other post with a different method:
Is both methods valid? Or is it boiling water better? Also, what if instead of using a dry frying pan i use the oven to bake the yeast? When i used the frying pan it toasted non-uniformly, so i was a bit afraid some yeast was left alive. I imagine using the oven it would heat more uniformly.
use the oven. Makes sense for the large packages. I will roast nuts and seeds in the oven as a fry pan tends to make brown spots if not constantly stirring and paying attention. Avoid putting things in the corners of a square pan as they brown faster. The middle takes longer so thin it out there for more even roasting/toasting/killing.
Another method is just to leave the bag of yeast in a sunny window of a locked up car on a summer day. :)
Ok, i will document the experiments here.
I tested the microoven and it didn't kill the yeast at maximum power for 30 seconds. Also i've tried freezing it and it was still alive.
I've tried the oven and indeed it toasted uniformingly. I've tested again with a cup of water plus sugar and yeast and at first it didn't produced any bubbles so i ate some. But some hours later i've noticed bubbles. I guess it lost power but was still alive. It's been 2 days and my stomach is a little funny. Not that much, but i've been feeling a little different, specially after eating a lot of bread and pasta in a very high-carb meal in the lunch. At dinner i tried a low-carb raw meal, similar to a anti-candida diet and felt better. I just don't know, is the yeast going to die or should i be very very worried about an infection?
Next time mix your yeast with some water and then zap it. Wet yeast is more vulnerable to being killed than dry yeast. More than likely your stomach acids took care of the yeast.
https://answers.yahoo.com/question/index?qid=20080814045346AAAwZgf
Some hours later.... don't forget that natural yeast could be on the sugar and dead yeast is great yeast food for all varieties. Can be you had dead yeast but introduced yeast or something else with the sugar or water or spoon or glass. We don't live in a sterile environment but our bodies have evolved to deal with those daily little pests. Trust your body to take care of it.
Well, i thought "know what?! better check a doctor anyway". After all health is our most important thing (bread comes 2nd place). Just to make sure. She said indeed not to worry, the gastric acid would take care of it. But it will in fact make you feel funny, so better avoid it anyway. Also, people with some immunodeficiency or unbalance in the digestive flora are better avoiding it at all.
I will try other methods of deactivation to make a comparison. I'll also repeat the oven, but with more temperature and care :p Indeed dead yeast is very valuable nutritionally. But i'm wondering: after boiling the yeast, how would you dry it?
Also i'm wondering, in terms of breadmaking...the actually-not-dead-yeast is now in my refrigerator. I'm wondering if it's fermentation power has diminished. If so, maybe i can add a great quantity of it in an bread recipe and it will add a nice flavor without compromising texture. Say, 50g instead of 10, for example.
You can put a normal amount or even a few tablespoons of it into a small loaf and see if it rises. If not. pitch in more and add some active yeast to boot.
One time we were experimenting on how much yeast is too much. I made a small loaf with several tablespoons of yeast clearly over the normal amount. My nephews ate it up like they were starving and even complemented on how good it was.
I've tried deactivating the yeast using the following methods:
-Boiling water (yeast was added in the water before it boiling point)
-Frying pan, until yeast is yellow (not in the photos)
-Frying pan, until yeast is darker yellow (not in the photos)
-Frying pan, until yeast is brown
-Oven, until yellow
-Oven, until darker yellow
-Oven, until brown yellow
Testing was always the same. A little bit of yeast and a little bit of white sugar. I've started the experiments two days ago.
As a control group i've also did the same with the brewer's yeast i've been buying for about 1 year and eating daily. Supposedly it's dead.
-----Results:
--Frying pan
Every batch made with the frying pan was still alive, even one that was very very dark and i could swear were dead! With some you could see the bubbles in a matter of minutes, while with others you could see bubbles after some hours.
--Oven
Every batch made with the oven was still alive. Again, with some batches you could see the bubbles in a matter of minutes, while with others you could see bubbles after some hours.
Two leftmost were 2 days old while the rightmost were minutos old in the picture. You could see bubbles in all of them.
This is the same from a top view. Notice the bubbles on the surface.
--Boling Water
It looked a lot like the brewer's yeast control group. When adding the other batches that were alive some yeast fell to the bottom, some stayed at the surface and some was floating up and down. The Boiling Water's batch instead just fell to the bottom and the water got a turbid color, just like brewer's yeast.
This is a photo of it, 3 days later.
More Photos
This is a photo of the first three batches. From left to right: Oven (yellow), then Boiling water, then Brewer's Yeast
Also, on a note, it can be difficult to differentiate between particles floating up and down and bubbles. But after some time bubbles should be clearly visible from the side or created on the surface.
On the third day
Frying pan and Oven batches we're still fermenting. While looking it was completely still, but it was just a matter of shaking and flicking the glass and you could clearly see bubbles. But there was a surprise. The baker's yeast on boiling water batch was still clear, with no bubbles at all. But the brewer's yeast batch showed a little fermentation! Some small bubbles could be seen on the water's surface!
I've been eating it daily for about 1 year and felt absolutely no side effects. In fact i know many people who eat it similarly.
Also, the boiling water batch curiously have a very light yellow color.
Theory:
Maybe a very small percentage of yeast is still alive in the brewer's yeast, and it's enough to reproduce in an ideal environment, given enough time, but it doesn't have the "starting power" to survive in our body.
Continuation of the experiments
Opinions on the viability of safely deactivating yeast for consumption?
Also, i'm still wandering how to dry the boiled yeast properly. I will do some testing.
Rather late but use the same sugar you used for the experiments...
Be sure to cover or not cover and give them the same times to "grow" as the yeasted glasses.
Previous test was made in a hurry, so i've decided to take some time now.
I've made some test with only water and sugar. None fermented.
Then i've made an test with
The same brewer yeast i buy at a food store and been eating for a year.
This time i've made the following steps.
This time i've put the same quantity of sugar and water (at the same temperature) at both, and at the same time.
Photos
Reults
The Brewer's sold at the food store did some fermenting at some time and after some days you could see a looot of bubbles.
Toasted-Boiled-Toasted Baker's Yeast did show some small quantities of bubbles only after some days.
Conclusion??
Baker's Yeast showed a bigger percentage of dead yeast than Brewer's Yeast and is safe to eat?