Harvesting Yeast from your Favourite Brewery

*Not my picture, taken from Google Image Search.

Requested by Jesse, this is a basic set of instructions for harvesting yeast from your favorite brewery for using in your own batch of homebrew.

There are a few things to consider if you decide on going this route:

– Some breweries filter the yeast and sediment out of their beers.  You cannot harvest yeast if there is none to be found.  The tell tale sign that a bottle of beer has yeast is if you find that sticky sludge at the bottom of the bottle.  A few GOOD bottles to harvest yeast from are Chimay and Southern Teir.

-Some breweries filter out their ‘good brewing’ yeast and add a ‘bottle conditioning and carbonating’ yeast..  If you harvest this secondary yeast and use it in your homebrew it probably won’t yield the best results as it is inferior.

-Harvest the yeast from a new bottle, as soon as possible from its manufacturing/bottling day.  Yeast do stick around for a while, but they do die off and become less effective later on.  If you try to harvest the yeast from a 2 year old bottle, you will only be harvesting yeast that has the ability to stay in suspension forever, meaning that if you use this in your beer it will take forever to ferment and will likely not clear, a la Orange Bastard!

-When you start with yeast from a bottle you have to grow enough of it to effectively ferment your beer, or you beer won’t ferment properly and will have a funny taste… a la Orange Bastard.

Recap.. Good Yeast, Fresh bottles, Grow lots, Be very sanitary!!!…

Here are the steps…

1)  Bring 1.5 liters of water to a boil in a pot and add 3.5 ounces of dry malt extract (DME) or liquid malt extract (LME) (you get either of this from a home brew kit, or at a home brew store).

2)  Boil the water and extract for 10 minutes in a pot.  Boiling the water for this long will sterilize the pot and the water.  Watch this stuff like a hawk!  It will want to boil over badder than Kraft Dinner, and it makes a hell of a mess!  Have a cup of cold water on hand for emergency an cooldown.

3)  Stop the boil after time is up, you should have around a liter of water left.  Put the lid on the pot.

4)  Fill you sink with cold water and carefully put the pot in the water.  Do not let any sink water get into your pot full of nice sanitized wort.

5)  Once the wort and pot are room temperature you are ready to transfer the wort to a sanitized container (either use a temperature probe that is sanitized, or just wait a long time.  You aren’t in a rush to cool this down quickly).

6)  Prepare a cleaned and sanitized container and lid.  I use a mason jar, wash it, rinse it well and put star san in it to sanitize.  If you don’t have star san you can either boil the container for a few minutes or use bleach but rinse it 100 times (bleach does not rinse very well).  There are other methods of sanitizing, but Star San IS the easiest and quickest.  Pick up a container of this stuff!  Its a must for any homebrewing!

7)  Pour your cooled wort right into the container, put the lid on and shake vigorously.   You are aerating the wort which is essential for yeast growth.

8)  Have a few bottles of beer that you intend to harvest yeast from ready.  This part can be tough, but you have to open each of them, gently pour almost all of the beer into a glass and drink it all.  (DO NOT DRINK FROM THE BOTTLE!!  This is a sanitary process, so get your lips and mouth away from the bottle – use a glass)

9)  With a little bit of beer in the bottle still, swish it around to loosen up the yeasty sludge at the bottom of the bottle.

10)  Sanitize the top and mouth of the bottle (I dip a paper towel in some star san and wipe down the mouth of the bottle).  Pour this yeasty sludge into your sanitized container that has your nicely aerated wort.

11)  Give another few shakes, loosen the lid so it just sits on top of the container and place the container in a dark spot that is room temperature..  A kitchen cupboard or closet works well.  Keep sunlight or fluorescent lights off the wort; incandescent lights are ok.

12)  The yeast might take a while to start doing their job as they have been in a semi-sleepy state from being in the bottle for a while.  Expect the yeast to do their job in a few days (2-3), but don’t worry if it takes a little longer.  You won’t see any vigorous fermentation – you may not see much happening at all.  A few signs that the yeast have done their job is that there is some co2 in suspension that may show tiny bubbles rising in the wort, and a nice film of white sediment has formed on the bottom of the container.  The white stuff is fresh yeast that is ready to be pitched right into your batch of homebrew.


Be sanitary!  If you make yeast dirty, you will have dirty yeast, dirty and infected beer, which is a waste of money and time.

You need to grow enough yeast to ferment your batch of homebrew (assuming 5 gallons).  Do yourself a favor and start with as much bottle yeast as you can – instead of 1 bottle of slurry, use 4 to 6 if you can.  The more the better.  4 bottles instead of 1 means that you will start off with 4 times as much yeast.

I have started to use this online yeast count calculator to give a better idea of how much yeast is require to properly ferment a batch of beer.  You don’t have to use it, but it really is useful!


According to this site you would have to make 2 to 3 starters to have enough yeast to make your batch of homebrew.  So what you would do after 3 to 4 days after your starter has been sitting is to start another one.  Put your starter in the fridge for a few hours to force the yeast to drop out of suspension.  Then decant off the ‘beer’ on top of the nice film of white yeast.  Repeat steps 1 to 5, pour the new cooled wort right on top of your yeast sediment in your container, cover with the lid and shake to aerate it.  The let it sit for a few more days.

Extra Note…

If you are going to be making a Pale Ale, IPA or something clean tasting, don’t go through the steps of harvesting yeast; just get a packet of dry yeast.  This is a bit of work to do and its not worth it for a yeast that has no real character to it.  However!  If you want to use a really interesting yeast that has loads of character, like Chimay!, go through the process of harvesting their yeast.  Large Chimay bottles are ideal because there is quite a bit of sediment/yeast in those things.

Extra Extra Note…

Save me a bottle.


4 Responses

  1. Thanks for the info Chris. I’m going to start making a honey porter tomorrow, but I think I’m just going to buy some liquid ale yeast for this one. It’s good to have this on record though, I definitely want to try this in the future. I think I’ll need to do it when I have more beer drinkin’ buddies over to help polish off 4 or 5 bottles of Chimay..

  2. For sure, harvesting yeast is pretty cool, but it does take a bit of work to get it right. I obviously didn’t do it the right way and ended up with a crazy beer. If I do this again I will take it all the way and actually follow all of the steps properly..

    Good luck on the Honey Porter, and save me a bottle!

  3. Question: Depending on the style of beer that you harvest the yeast from, would it be best to also brew the same style of beer with that yeast? (Ex. yeast taken from a dark ale would best used to produce another dark ale) Or does it not really matter that much?

  4. Well yes and no. You typically choose a yeast strain to give certain characteristics in the beer. A lager yeast will typically ferment at 12C and give off clean characteristics, where a trappist yeast strain can ferment up to 27C and give off banana, bubblegum and other fruity notes. So while you can use a lager yeast out of its typical fermentation temperature range and force it do do things that it doesn’t like to do, you won’t get the best results.

    But if you talking about using a Chimay yeast for a dubbel (dark beer) or a tripel (light beer), then yes you can do that. Infact, Chimay just uses one type of yeast for all three of their beers, so does the rest of the Trappist ales. And typically the only difference between a dark and a light beer is the addition of specialty malts that give a dark appearance. Like, if I add a few ounces of chocolate malt, I will have a dark looking beer. But this does not change anything for the yeast.

    Whatever yeast you do use, expect it to give similar characteristics to the beer that you stole it from. Ex. If you use Chimay yeast for an IPA, expect to have fruity notes in your brew.

    So depending if you are trying to achieve a certain style it does matter to use a yeast strain within its given style characteristics. If you are experimenting and don’t care about achieving a specific style then if does not matter.

    Save me a bottle.

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