Freezing Yeast


Homebrewers often find they would like to have yeast at the ready, to defray costs or to be able to collect strains that are not readily available and grow them to a practical amount of yeast. I looked into yeast ranching with slants and decided the chore of sterilization and reculturing would be too much for me to handle. An excellent book on that subject is “First Steps in Yeast Culture” by Pierre Rajotte.

I decided to look for a different method and tried freezing yeast with glycerin based upon posts on rec.crafts.brewing. My results using a frost-free freezer were a total disaster. The freeze/thaw cycle of the fridge caused the yeast to die. The idea is when freezing/frozen the glycerin helps to keep the cell walls of the yeast from bursting. The freeze/thaw cycle can be the kiss of death depending upon how the yeast are stored.

 A few years later a brewer suggested I try a non-frost-free freezer and gave me a protocol. He used a lab freezer at –80ºF and a 15% glycerin solution. I had a regular upright freezer at work that ran about –5ºF and decided to give it a whirl.

 Here is the protocol I utilized (Many thanks go out to Brad Nicholson).

 Necessary materials and equipment:



Yeast slurry (from bottom of starter)

Pipette (or other measuring method)

Test tubes and caps (sterile, or sanitized)

Masking tape

Permanent marker

 The #1 thing to do is to have surfaces and equipment sanitized. Take nothing for granted.

 1)      Mix glycerin and water in the ratio of 30 ml glycerin to 70 ml water. This will yield a 30% glycerine solution.

2)      Microwave the mixture until boiling.

3)      Remove to the counter, cover with saran wrap and allow to mixture cool to room temp.

4)      Add equal amounts of the 30% glycerin solution and the yeast slurry to the test tube. (The amount will be dependent upon the volume of the tube.)

5)      Cap the tube and shake.

6)      Mark a piece of masking tape with the yeast type and label the tube.

7)      Freeze

 Glycerin can be purchased at most local drug stores, but can sometimes be difficult to locate in the store. Be diligent and you will find it. If in doubt, ask the pharmacist and they can point you to it.

 You now have a frozen tube that is 15% glycerine and yeast. When I get a new strain, I try to make at least 3 tubes from the starter slurry. My procedure is to hold my finger on the end of a pipette and stick into the slurry and remove my finger allowing the slurry to be sucked into the pipette. I transfer that into the test tube as many times as necessary.

 My yeast samples were kept frozen in the freezer, but eventually I had to remove them from my employer to the house. I put them into a cooler with ice packs and brought home. I then placed them into a thick foam cooler with frozen ice packs to prevent the freeze thaw cycle of the frost-free freezer from killing the yeast. Recently I revived the yeast by putting them on a stir plate with a small amount of starter wort and gradually adding more wort over time. The yeast revived perfectly after more than a year of frozen storage. The only caveat is the yeast had to grow so the results took longer than yeast abuse.


Another great page on freezing yeast is Mike D’Brewer’s entitled Yeast Harvesting and Freezing. I was going to take pictures for this page, but his are excellent.


Ginger Beer Plant

The following is basically some recipes and some notes about Ginger Beer Plant. The notes are ongoing and so newer notes will be placed at the top of the page and older ones at the bottom. Once I get it tacoed out much of the information may be deleted since it will be obsolete.

Most current base recipe (7-4-06):

2 Fingers Ginger
Zest of 1 lemon
150g Brown Sugar (7-9-06, trying 125g Brown Sugar)
1/4 teaspoon Cream of Tartar
Juice of 1 lemon
Water (no chlorine)
Ginger Beer Plant
Peel ginger and process in food processor till minced. Add zest of 1 lemon and ginger to pyrex measuring cup and top up to 1 cup of water. Microwave to boiling, remove from microwave and cover with plastic wrap to cool. Add lemon juice, brown sugar and cream of tartar together and allow to sit. When ready to combine ingredients, put cooled ginger and zest in yogurt or other fine mesh strainer and mash to get all the ginger juice possible. In quart mason jar combine all ingredients with GBP, top up with water, stir to combine, and cover loosely with mason jar lid and ring. Place on window sill for two days.

After two days put into one liter plastic bottle, squeeze all air out of bottle and cap. Allow to carbonate for two days. Place into fridge till ready to consume.


Do not bottle in crown capped beer bottles, the pressure exceeds 60 psi during carbonation.

For Ginger Beer Plant information please see:

Notes from talking with Raj and others (all may not be proven)

No sanitation is required.

The longer the minced ginger sits in water the hotter (more spicy) it will become. (note: 7/7/06, this has proven to be true)
The shorter the fermentation with the GBP the more spicy the ginger, the longer the more lactic the beverage.
The GBP creates lactic acid and CO2 unlike normal yeast which create alcohol and CO2, this is why the beverage remains low abv.
The GBP can be dried (unlike kefir grains).
Water MUST be cholorine free.
Reason for using of Cream of Tartar is not known. (note: 7/7/06, CoT is for head formation)
GBP from Raj came from lab in Germany.
Questions (that I keep wondering)

Does the GBP ferment the ginger or the sugar? – (it would appear to be the ginger since the residual sweetness as of late has been pretty high and with yeast nutrient in a simple sugar fermentation the flavor becomes very dry.)
How much Jamaica (Hibiscus) is needed to give the desired color and flavor?
How would a 100% ginger and no sugar Ginger Beer ferment, would it ferment with GBP? – (if so, one could sweeten to taste with Splenda and have a sugar free ginger beer)
Will more Cream of Tartar result in larger and longer lasting head?
Does the ginger really need to be microwaved or could it just be made to a slurry in the food processor?
Batch Notes

Upcoming trials – Hibiscus, no lemon, lime, lemon/lime, different sugars, etc…

Batch 10

No lemon or lime till bottling time. Ran out of BS so 95 g BS and balance of 125 g was table sugar.

Batch 9

Using 4 Key Limes for their zest and juice. 125 g BS and continuing the bit of water in the food processor. Removed GBP for sharing, the GBP had not grown considerably as was though. Refilled the contained given to me by Raj and only had about 1/4 of the amount of GBP as before. However, the batch fermented just fine.

Batch 8

Lime zest and lime juice instead of lemon zest and juice. Still using 125 g BS. This time added a smidge of water to the food processor after intial cut up ginger was processed which made a fairly smooth ginger slurry which was easier to squeeze against the yogurt strainer. The amount of GBP does not seem to be increasing, might be time to pull some out to share on the next batch, I was hoping it would increase more.

Batch 7

Still 125 g Brown Sugar, but added about 1/4 oz (wt) dried hibiscus to the water/ginger/zest after heating in micro. Might work out better to do less in it’s own steeping liquid. Seemed to absorb a fair amount of the liquid when rehydrating. Left it and the ginger to rest overnight (12 hours). Forgot the CoT so added at the time GBP was added.

Batch 6

125 g Brown Sugar trial. Only fermented for 1.5 days.

Batch 5

Just about enough GBP to share. The sweetness on this batch was still a bit too strong for my tastes. If later batches with 100% brown remain this sweet after cutting back the sugar, it may get cut a bit with table sugar since those batches did not seem quite as cloying. The heat from the ginger was just about right, could have been boosted a smidge, but on target for my tastes.

Batch 4

100% brown sugar, continuing the food processor and yogurt strainer routine. The head was perfect and well lasting on this batch, the CoT really seems to do the trick. The sweetness was a bit too high on this batch, will cut it back for B6 trial. Seemed fine with 50/50 cane/brown, but too sweet with 100% brown.

Batch 3

Ginger processed in food processor and allowed to sit and cool for 8-10 hours before mashing against yogurt strainer. Much easier process. Pressure measured on plastic bottle, 35 psi at one day, over 60 psi at day two. Still 1/2 table sugar and 1/2 brown sugar. As suspected, the food processor and allowing to sit caused the ginger to be very spicy and peppery. The Cream of Tartar definitely is used for head formation and causes a huge head to form. The head does not stay around for a really long time, but rises very tall and large bubbled.

Batch 2

Two fingers of ginger, no head, sugar about right, 150g – 1/2 table, 1/2 light brown. Ginger chunked and then squeezed in garlic press after microwaving. Fermented for two days and carbonated for two days. Process seems to speed up in window sill, perhaps the GBP prefers light. All air squeezed from bottle. Very spicy, though not overly so. Sugar was fine, but was told that it may have been a bit light by the wife. Wife did not like slight lactic flavor, I found it refreshing.

Batch 1

Only one finger of ginger was used and too little sugar with 1/2 sugar being table and 1/2 light brown sugar. Ginger chunked and then squeezed after microwaving. No head on ginger beer, not very spicy and low on residual sugar, slight lactic aroma. Took forever to ferment, 3 days to even begin. Started with small amount of GBP given to me by Raj at the AHA convention.


Starters and Pressure Canning Wort

When I originally started brewing, I never made a starter. I had decent results, and whenever I made a beer with an original gravity higher than 1.060 I always tried to reuse yeast from a previous batch. The reason I didn’t make a starter was not because I didn’t think I needed to for proper fermentation and reduced lag times, it was because I HATE TO MAKE A STARTER. More on that in a second…

If you want to make a starter the traditional way, then Mike Uchima has an excellent page on that called Making Yeast Starters.

My problem was, I just could not stand spending 20 minutes to an hour getting yeast ready for the brew day. What I really wanted to be doing was brewing. Also, I hated being a slave to the smack pack. I always found that waiting on those things to swell was an absolute pain.

Then I found the “Confesions of a Yeast Abuser” page, although recently Domenick Venezia has renamed the page Yeast Starter – With Stirring Aeration.

I swapped a buddy some homebrew for a stir plate, and was off to the races. I modified the original procedure slightly. I figured if the outer pouch contains the yeast and the inner nutrients necessary for yeast growth, why am I adding YNB. So I just smack the pack and immediately put the package contents into the stirred starter.

Also the article refers to the stirring as aeration. I believe this to be true initially, but after the fermentation of the starter begins, the starter is giving off CO2, so with an outflow of CO2 from the starter container, I cannot see how much additional air can be getting in. I believe the stirring helps get the yeast in contact with the wort and adds air, which leads to a larger yeast population. Of course all this is conjecture on my part, but it works like a champ.

Here is a picture of my stirrer, an Erlenmeyer flask, and a mason jar.

Now I was no longer a slave to a smack pack, but I still had to make the dreaded starter. Very soon I tired of making the starter. I found it to be boring and tiresome.

So I searched a little more and read a few articles on Canning Wort. Unfermented beer wort pH is not low enough (4.6) to be considered safe for just water bath canning. A temperature of 240 F for 15 minutes is necessary to kill Botulism spores that could eventually produce deadly toxins. 240 F happens to be a pressure of 10 psi in the canner. In my own pressure canning of wort, I use 15 psi, 250 F, for 15 minutes. For more on canning you should check out the National Center for Home Food Preservation, and for more on botulism take a look at the CDC website.

This is my pressure canner.

It is an All American, and I obtained it off Ebay for $25 (a steal). It will hold 7 quarts, or 6 quarts and 2 pints, as shown in the picture below.

I like having some of both size canned, that way if I want to step up a starter while stirring, I can use more or less wort as needed. Wort will darken slightly in the canner, and will also undergo the boil. The picture below shows wort that has been pressure canned on the right, and on the left is wort awaiting canning.

It is a little difficult to tell the color difference, but you can definitely see the hot break in the bottom of the jars.

My procedure is to mash a grist of 100% Pils or Pale malt and after the sparge to can the unboiled wort. This gives me quite a few starters. The day I took these photos, I canned 22 quarts and 12 pints, as shown in the photo below.

So for starters, my procedure is to first use impeccable sanitation. The I smack the smack pack and dump the contents into a flask or mason jar and add the canned wort and the stir bar and place the starter on the magnetic stirrer. I then cover the top loosely with plastic wrap, or an airlock. Usually I have aerated the wort by splashing before and as I add it to the flask or jar. I really like the method because I am not tied to a smack, and I am not tied to a starter. Also when I pressure can starters I am brewing an entire batch of beer, which is what I wanted to do in the first place!


Mike’s Homebrewing Page

Welcome to my Homebrewing page!

I hope you will find something here that helps you in your own brewing, or that you might find interesting.

I have been brewing since 1998, and have progressed from Extract Brewing to Extract with Grain on my 3rd batch to All Grain on my 25th batch about a year and a half after I started brewing. I have increased my knowledge of brewing over the years and served two years as the local homebrewing club’s, CARBOY, Education Vice-President. Since I began brewing, I have won several awards in competition for my beers, and I have taken and passed the BJCP exam to become a Beer Judge and currently I am ranked as a Certified Beer Judge and after a few more judging points will be ranked National. In 2002, I came in third for North Carolina Brewer of the Year. I generally brew multiple batches on the same day with different mashes to end up with two to four 5-gallon batches at the end of the day. I prefer variety, and if I brew a recipe twice, I usually tweak it some the second time around. I post frequently on rec.crafts.brewing, and I lurk around on the HBD and Brews&Views as well as many other homebrewing and beer sites.

Below are some pages about my brewing equipment and techniques.

Fermentation and Serving – I think I am unique in this aspect. I know a few folks with more elaborate systems, and some with similar equipment, but I cannot think of anyone with more flexibility and variety.

Inexpensive Rectangular Mash Tun – This is the mash tun I started with, and still use to this day. It generally runs in the 80-85% efficiency, and I think once you see the simplicity and low cost of it, you will no longer be scared of the potential costs people often associate with All Grain equipment.

Malt Mill and Large Hopper – This is my malt mill that I motorized, and the large hopper I made for it. I wrote an indepth article about motorizing a mill that you can link to.

Propane Burner conversion for Sanke Kettle – This is how I made a three legged propane burner work for my converted Sanke kettle which was originally too large in diameter to fit on the burner.

Setup and Mashing Techniques – This is a rundown of my brewing setup, and the techniques I use to make the brew day more productive.

Starters and Pressure Canning Wort – This is how I make starters and the procedure I use for pressure canning wort for starters.

Freezing Yeast – This is my method from freezing yeast and then bringing them back to life.

Measurement Devices – This page details some information on Thermometers, Hydrometers, and Refractometers.

Counter Pressure Bottle Filler – This is my filler that I designed.

Great Taste of the Midwest 2003 – Twelve of us from North Carolina made the trek to the Great Taste in Madison, WI. This is highlights of that trip!

Here are several articles I have written.

Building a Keg Pressure Tester – This is a device all people who are kegging must either purchase or make. It is the only way you can insure the pressure in your keg is exact. (Word version)

Cleaner or Sanitizer? – This article lists a majority of the cleaners and sanitizers on the market and their recommended concentrations to properly do the job. (It is about midway through the newsletter or Word version.)

The Brewing Library – This is a list of the publications you might want to get to establish a decent brewing library. (It is about midway through the newsletter)

Motorizing a Malt Mill – An indepth article on how to go about motoring your mill. The article should be applicable to any type of mill that can be motorized. (Word version)

Yeast Washing, Quick and Dirty – An article taken from the information on the Wyeast website, and an old article by Robert Arguello. (Word version)

Cleaning and Rebuilding Ball Lock Kegs – A slightly dated article but with good information. It should be updated to suggest cleaning with Straight-A, and sanitizing with StarSan. (Word version)

Lubricants for Keg Parts – An article describing what “keg lube” is and might be.

Base Malt Steeping Experiment – An article on whether base malts can be steeped or not. I conclude they must be mashed, and not simply steeped.

Below are links to many of my recipes that have done well for me in various competitions.

(The recipe Aye Corona was meant to be a crowd pleaser for a party, and has become a favorite of many of my homebrewing friends, some who brew it fairly often.)

Fuggled Up Pale – ESB recipe I brewed to get rid of a plethora of Fuggle Hops, 5 gallon recipe.

140/- Shilling Historical Scottish Ale (1850) – Very strong historical Wee Heavy, 3 gallon recipe.

IP Freely – IPA recipe that was brewed to get rid of Cascade Hops, 10 gallon recipe.

Klassic Kolsch – Very good Kolsch recipe, 5 gallon recipe.

Altstadt Alt – Very good Dusseldorf Altbier, 5 gallon recipe.

Red Mild – Very good mild that uses quite of bit of cane sugar, 5 gallon recipe.

Bigfoot + – Sierra Nevada Bigfoot Clone that doesn’t miss by much, 5 gallon recipe.

Weizenbock Party – Helles Weizenbock that is excellent, though very light, 5 gallon recipe.

Historical Porter – My first shot at what a historical Porter would been like, and a great beer, 5 gallon recipe.

Spaten + – A decent Oktoberfest/Maerzen recipe, 5 gallon recipe.

Red Ryder – A California Common recipe originally given to me by Mike D’Brewer, 5 gallon recipe.

MD CAP – My Classic American Pilsner recipe, 5 gallon recipe.

Berlin-Er-We-I-See – My Berliner Weisse recipe, 5 gallon recipe.

Wit or Witout – My Belgian Wit recipe, 5 gallon recipe.

Now We’re A Bruin – My Oud Bruin recipe, 5 gallon recipe.

Mike’s Hard Lemonade – An experiment that got out of hand, 5 gallon recipe.

SinSaisonal – A very good Saison, 5 gallon recipe.

Aye Corona – A no style beer that is a crowd pleaser. Plenty of alcohol, and a really nice finish. You can increase hops and other ingredients as you please. The key to this beer is the corn, the honey malt, the mash temp, and the yeast. 5 gallon recipe.

Historical Recipes
Below are a list of the Historical Recipes I have brewed and some notes about them.
A few appear above and have won awards in competition, but most were brewed just to see how beers you cannot purchase today would have tasted originally.

1908 Kentucky Common – This recipe is a naturally soured brown ale that was brewed in Kentucky around the turn of the century. I decided to go the route of yogurt to sour the mash, if I made it again, I would use grain. It is a quite refreshing, slightly sour brew that was a favorite of many.

1837 Historical IPA – This recipe was send to me by Andy Davison before I had a copy of Old British Beers and How to Brew Them. It is an 1837 IPA recipe. It uses nothing but pale malt, and the original hops were Kent Goldings. I substituted Fuggle for bittering, and used Kent Golding for aroma and dry hopping. The beer is surprisingly balanced and very good.

1850 Historical Scottish 140/- – A recipe from Noonan’s style book. This beer is only a 3 gallon recipe and requires a large amount of malt, and caramelizing the first runnings. It only gets better with age, and stands the test of time as good as any strong beer. It is a very potent brew.

Historical Porter – When reading the book on Porter, I decided to try and brew one based upon the recipes and descriptions given in the book. This was and excellent beer, and one I will try again.

Classic American Pilsner – This is a pre-prohibition recipe. CAP only exists in homebrewing, and this recipe is a good one for the style. In 2000 CARBOY brewed a commercial sized batch of CAP for NHD. The details on that can be found here NHD2000.

Beer Judge Exam Study Aids – BeerStud
In our area we have a YahooGroups site that has many good links and lots of files that help brewers prepare for the BJCP exam. (Current BJCP Exam Schedule) If you are interested you would need to join the group. It is called BeerStud and to be included, you would need to send an e-mail to BeerStud to join, and give your name and city/state in the body of the e-mail. Once signed up, you can change the format, to read on the web, digest, etc. If you are not going to take the exam when given in our area, I suggest you change your format to digest.

Here are some Palm versions of the BJCP Study Guide and the BJCP Style Guidelines. These will require an E-book reader to view. I use CSpotRun.