How-to Make any yeast Gluten-Free

tbeard · 03-30-2010, 05:34 PM

There are two main ways to make a yeast GF, the first is isolation then inoculation, the second is a dilution solution.

We will start with the more complicated isolation and inoculation method. First you will need to pour GF agar plates, I would follow dkershner's method for making and canning starter wort, http://brew.dkershner.com/2010/step-by-step-making-and-canning-sterile-starter-wort/ with slight modification. 1st make sure the wort is GF, then add 10g/L agar (which can be found at a health food store) proceed with sterilization, but only fill the mason jars 1/4 of the way full (smaller mason jars work best). Finally when the jars are cooling set them at an angle so the agar hardens in a slant. You have just poured your first Media Slants.
Now comes the isolation portion, first you need a loop, commonly that is a metal loop that will pick up a small amount of media held in place via surface tension. Practically anything will work here, and if a loop is unavailable a metal fork with a wooden handle will work in a pinch. The goal now is to sterilize that fork or loop, I suggest a propane torch and heat the whole loop until the metal gets red hot.
Now that your loop is sterile, let it cool, then touch the loop to the yeast, to pick up a small amount of yeast and media. Now very lightly streak the loop onto your hardened GF agar, we are not trying for isolation here so I will not get into single colony isolation. close up the mason jar and incubate until colonies can be seen, you have now started your own Yeast collection. Now you simply inoculate your GF starter cultures using your loop and a small amount of yeast colony.

The second method of making a yeast GF, is the dilution solution. I would like to note that the standard for GF is 10ppm, and actually most liquid yeast is only 2ppm. This 2ppm can still be too high for people who are very sensitive to gluten, what we want to do is dilute this 2ppm (parts per million) even more.
Essentially you want to add a very small amount of liquid yeast culture to GF starter wort, if you diluted 1ml into 999ml you have just diluted your gluten to 2ppb (parts per billion) a 1:1000 dilution. Now let it grow up and you are ready to inoculate.
If 1Liter starters are unavailable to you, or you want even less gluten in your starter, take a small amount of this starter after it has grown up overnight, and dilute it again into another 999ml you now have gluten in 2ppt (parts per trillion) which is undetectable by the best of scientific equipment.

Congratulations you have GF yeast and a little hands on experience with sterile technique

DKershner · 03-30-2010, 07:21 PM

A couple notes, just for accuracy's sake.

The yeast from white labs is approx 20ppm, which amounts to 2ppm in a final product (5gal of beer). Therefore, your starting number should be 20ppm (can someone verify this number for me?). I am unsure on how much Wyeast has in the starting place, but it is thought to be much more.

Also, for everyone else, there is a good step by step with pictures (I am much better off when I can see it) using non gluten free methods to much of what tbeard speaks of. Here: http://www.homebrewtalk.com/f163/slanting-yeast-133103/

Otherwise, it looks like a wonderful way to dilute gluten in yeast, good write up tbeard!

tbeard · 03-30-2010, 08:02 PM

Thanks for clarifying dkershner, so a quick change to the calculation 20ppm in a 1:1000 dilution makes 20 ppb etc. could also do a 1:10000 dilution which gets you back at 2ppb. This would explain why these liquid yeasts are not GF.

**uechikid** · 03-30-2010, 08:21 PM

I emailed White Labs to see if they have a gluten free yeast and this was there reply:

According to a recent FDA ruling, anything under 20 ppm can be considered gluten free. Our yeast analysis: Yeast slurry in package~12 ppm. When our yeast is used with ingredients such as sorghum to make gluten free beer~2 ppm. Therefore, beer made with our yeast will fall under that amount and CAN be considered gluten free.

**The European standard for gluten free is below 100 ppm.

Pam Marshall

Sales/Customer Service

White Labs, Inc.

888-593-2785

858-536-4587 (Direct)

www.whitelabs.com

DKershner · 03-30-2010, 09:11 PM

12ppm in a 1:1000 would be 12ppb. Which in the final product (in the case of 5gal of beer) would be 2ppb. That's pretty damn low, low enough that next to no one would be reacting to it.

And thanks for giving the actual number uechikid.

**uechikid** · 03-30-2010, 11:47 PM

Your welcome. Just trying to do my part.

**Lcasanova** · 04-01-2010, 03:41 AM

Nice work guys...I probably should have read the links but...if I got a gf beer like Green's (which I think are bottle conditioned) and wanted to harvest that yeast...could I just flame the top, pour my beer and add some prepared wort to the sediment left in the bottle and let the yeast grow??? If that worked I guess you'd eventually put that in a larger container and grow that up then pitch into your beer...

tbeard · 04-01-2010, 01:34 PM

That method would likely work, I would be concerned with infections. I think you might be more successful by streaking a small amount of beer out on one of your slants then growing those isolated colonies. The reason being that it will be very hard to add sterile wort to a beer bottle, while avoiding infection. But I suggest giving both methods a try, experimentation is half the fun.

**Lcasanova** · 04-01-2010, 02:17 PM

Maybe I'll give that a shot, I don't think I have the time nor tools to do slants and loops.

DKershner · 04-01-2010, 05:34 PM

Quote:

Originally Posted by lcasanova

Maybe I'll give that a shot, I don't think I have the time nor tools to do slants and loops.

Here's a good discussion on bottle harvesting...can't seem to find the tutorial someone did. Had a video too I think. It's not too difficult, but the success rate is a mixed bag.

http://www.homebrewtalk.com/f163/harvesting-rogue-pacman-bottle-what-i-learned-162965/