Sorry, But Commercial Fresh Yeast is Not Natural

Sigh. I just got off the phone with the corporate office of Kneaders Bakery and Cafe.

Here's the problem, which a lot of people are confused about. My wife came home a couple days ago with a take-out bag from Kneaders. Here is what it says on the bag: "We love great European bread! We love everything about it -- the simple pleasure of kneading it by hand, the rich aroma of the levain (natural yeast)..." The parentheses are theirs, not mine.

The moment I read this on their bag, I knew it was not true. I wish there was a "magic" natural yeast -- by magic I mean a natural yeast that acts like the genetically modified yeast used commercially and sold in grocery stores.

But there is not.

And I also knew exactly what was going on with Kneaders -- they are not trying to lie to their customers. They just don't know what they are talking about. They have confused "natural" yeast with "fresh" yeast, like so many other people.

There has been a lot of confusion about this lately. I've been getting a lot of emails about it. Here is an email I got this morning from Arlene Butler, who is the Taste of Home field editor & former writer for the food section of the Ogden Standard-Examiner:

"Ten years ago my son brought a sourdough start home from his mission. It's history goes back to the Yukon & Alaska gold rush. It is an amazing start! It has a good balanced flavor and is very vigorous. I guess it had to be vigorous to survive the cold (minus 50). We also tried several other starts including a Mormon pioneer start that the people in Ft. Bridger WY have kept going but it was not as strong - the loaf was heavier.  No other starts have compared to this one. I just wanted to share that this start has gone 4-5 months (while I remodeled my kitchen) without being fed!  I am not sure why you have to feed yours twice a week but I am thinking it is because you are keeping it active."

Here is what I wrote back to her: 

"Thank you for your email. The problem with so-called "gold rush" starts is that the recipe to "start" them is to go to the store, buy dry yeast, and make a "start" -- which means that the start is simply fresh yeast, not natural yeast. Which is why your start was so vigorous (it is genetically modified and not natural). Kneaders is also advertising that they are using "natural" yeast but if you call their corporate headquarters, they say it is fresh yeast. Which means it is genetically modified and not natural. Melissa and I are very, very careful to make sure that any yeast we use and hand out is documented natural yeast. This is because if the yeast is just fresh, it does not predigest the gluten, which is exactly the same as using grocery store yeast. I hope that helps."

I spoke this morning to the corporate headquarters for Kneaders. David Vincent is their corporate baker and yeast expert. He had no idea that commercial yeast is genetically modified and is not natural. Here is what he said, through a spokeswoman, to me: "We do use a commercial yeast, so there is no guarantee that it is not genetically modified."

So what they are advertising as "natural yeast" on their take-out bags is actually just fresh yeast. There is so little education about the fact that commercial yeast has been genetically modified to be vigorous, but not to eat the gluten. I don't know what to do about this except keep speaking out and trying to educate people.

This is a painful subject for me because I have a friend who bought an enormous quantity of my books and immediately went to a local bakery, bought some of their fresh yeast, and started using in all our recipes. And it works perfect. Unfortunately, it is genetically modified and not at all natural. I have not had the heart to tell her this yet. I got another email earlier this week from someone who said to me that they wanted to use "dry active yeast" from the grocery store as natural yeast in our recipes. In our book I wrote that yeast was genetically modified in 1984. This person's logic was this: Dry active yeast -- freeze dried yeast -- was invented in World War II and therefore should still be natural as long as it is not labeled "rapid rise" yeast.

Here is the problem. Since our book was published, I have learned that yeast was genetically modified long before 1984. In fact, yeast is the preferred and original test subject for genetic modification. This is because it grows very fast, is a simple organism, and is free. If has been used by universities and laboratories to study genetics for decades. It is the most used genetic modification test subject still to this day, because it is free and easy to use, and there are more than 1,000 varieties occurring in nature, so there is lots of room for study and work. I have not yet been able to determine what year yeast in the grocery store first became genetically modified, but I now know for sure that it was before 1984.

Here is the other problem, to be frank. I preface this by saying that I'm not complaining, I'm simply explaining. I have other books to write, and other work to do (not the least of which is my full-time job), and no one is paying us for all this work and research. Our publisher has sold 10,000 copies now of our natural yeast cookbook, for which I will, in six months, be paid $2,000 as my wage. And that is less than I spent on photography of the recipes and supplies for creating my recipes in the book. So I've made exactly $0 for three years of work. I will continue to work on yeast research as I can, but you have to understand that this is volunteer work on my part, even though it directly affects the health of hundreds of millions of people who are being made sick because genetically modified yeast does not digest the gluten in flour. I'm doing what I can, as fast as I can. -Caleb


  1. Thank you for all of the work you have done!! I am fascinated by this information on yeast, and want to try using it. But I am a little intimidated. Don't worry though I will get over it and send you a self-addressed envelop!

  2. Nicely said. Also, sorry for the set back in profits. One of these days you'll be famous AND rich.

  3. I am very grateful for what you are doing. Perhaps you should put a "donate" paypal button on your blog?

  4. Hi Caleb, I absolutely love what you are doing. I personally know that Kneaders uses a 200 year old start in their artisan bread because I feed it every morning. We do use commercial yeast, but it doesn't go in the artisan bread. I hope you will contact David Vincent again and seek to clarify the misunderstanding, thanks!