How (and why) to Make a Yeast Starter

Making a yeast starter for your homebrew is a fast and easy way to gain more control over your final product and ensure the results you are after.

Let's start with the "Why" of making a yeast starter for your homebrew.  First, it should be acknowledged that making a yeast starter is by no means required.  Most beginners, including myself, have pitched the dry yeast packets that come with a basic kit and achieved acceptable results.  Some opt for the liquid yeast varieties from either White Labs or Wyeast and the results are sometimes even better.  So why ever bother with the extra steps of creating a starter?  Below are a few reasons that I think make the exercise worthwhile:

1. Build up the cell count.  The more active yeast cells you have the more they can get to work and do their job of converting sugar to alcohol.
2. Full fermentation.  With more active yeast cells you have a better chance of achieving your desired finishing gravity.  Let's say you start off with an original gravity (OG) of 1.051 and want to end up at 1.012.  If you under pitch the yeast and the rising alcohol content overwhelms the active yeast you could stall it out before reaching your final gravity and not reach the desired alcohol content.
3. Reduce risk of contamination.  The faster your yeast is able to do it's job the less time your beer has to be exposed to contaminants.  The less lag time you have the less chance of contamination.
4. Better tasting beer!  Yeast does more than just convert sugar to alcohol.  It contributes to the overall taste of your beer and when it is pitched in the proper ratios it can help reduce off flavors.

Let's move on to the the "How" of making a yeast starter beginning with the equipment and supplies you will need to get started:

1. 1 gallon glass growler or a 2 liter glass pyrex flask
2. Rubber stopper and airlock
3. Approximately 1/2 cup light dry malt extract (DME)
4. 1 quart of water
5. Aluminum foil
6. Medium-sized sauce pan
7. Yeast appropriate for your homebrew recipe

Making a yeast starter is actually very simple.  In fact, if you've made even one batch or beer you have already done most of the basic steps.  While there are variations galore on how to do this task, I find the steps below are easy to follow and yield consistently good results.  Begin your yeast starter at least 2 days before you intend to brew.

1. Start by removing your liquid yeast pack or vial from the refrigerator.  If it is a "smack-pack" go ahead and activate as per instructions.  Your yeast should have several hours to warm to room temperature before moving to step 2.
2. Bring 1 quart of water to a boil.
3. Add 1/2 cup of light dry malt extract (DME) and stir until dissolved.
4. Boil for approximately 15 minutes.
5. Cool the DME and water mixture (wort) by placing the saucepan in sink and surround with ice water and stir gently until liquid is room temperature or below 80 degrees.
6. Transfer cooled wort to carboy or flask.
7. Add (pitch) yeast to wort.
8. Cover with aluminum foil and shake vigorously to aerate.  You can also choose to oxygenate the mixture.  Instructions can be found HERE.  Note: reduce time to 10-15 seconds.
9. Add rubber stopper with airlock and allow to begin fermentation at room temperature.
10. You should see fermentation activity within 24 hours if not much sooner.
11. You now have your yeast starter!
12. When it comes time to pitch your yeast in you homebrew recipe you can simply pour the entire mixture into the fermentation vessel or use this optional method:

• Optional - 24 hours prior to brew day you can transfer your wort to the refrigerator.  This will cause the yeast to separate or sink to the bottom of the container.  Remove from refrigeration and pour off most of the top liquid.  Let the remaining yeast warm to room temperature and pitch the resulting yeast slurry into your wort at the appropriate time.  Removing the extraneous liquid may reduce off flavors.  

Well, that's it.  I hope you find this a useful process in your homebrewing adventures.  Happy brewing!

See these links for more information on creating a yeast starter:

• Making a Yeast Starter by Beer Geek Nation
• Making a Yeast Starter by Brew Your Own Magazine
• How to Make a Yeast Starter by Joe Polvino

Related articles

• Homebrewing: Fine-Tuning Fermentation (suburbanmen.com)
• Homebrew Batch #6 Notes - American Pale Ale (Full-boil, non-kit) (andyslusher.blogspot.com)

Batch #6 - American Pale Ale (Extract, Full-Boil, Non-kit)

For batch #6 I'm taking a baby step toward all-grain. For this batch I'm going to do a full-boil extract brew using DME only.  I'm going to also move away from the kits I've been using and make up my own simple Pale Ale recipe.

Equipment:
First task at hand is upgrading my brew kettle.  I wish I had sprung for an 8 or 10 gallon pot initially over the 6 gallon model but lesson learned.  Next is to get a chiller.  Cooling 2-3 gallons in an ice bath is pretty easy but I don't think there is an efficient way to rapidly cool 5 gallons of wort without a chiller.

Ingredients:

• 5 pounds Light Dry Malt Extract (DME) - Munton's Light
• 1 pound Amber Dry Malt Extract (DME) - Munton's Amber
• 1 pound Crystal/Caramel Malt 40L grain for steeping (color + fermentable)
• 1.5 oz. Cascade Hops for bittering
• 1.5 oz. Cascade Hops for aroma
• 1 Whirlfloc tablet (an Irish Moss product)
• Yeast - American Ale from Wyeast #1056
• 5 oz. Corn Sugar (Dextrose) for priming (bottle conditioning)
• 6 gallons of drinking water

Process:

1. Two days before brewing session make a yeast starter.
2. Bring 5.5 gallons of water up to a temperature of approximately 158 degrees.
3. Pour all of the Crystal/Caramel Malt into a grain sock and submerge in water for 20 minutes to steep. Maintain a temperature between 150-165 degrees for steeping.  Be careful not to let temperature rise to 170 or above to prevent off flavors from being introduced.
4. Remove grain sock and allow excess water to drip back into pot.  (Do not squeeze)
5. Bring wort to a gentle rolling boil, remove from heat and add 3 pounds of the Light Dry Malt Extract and 1 pound Amber Dry Malt Extract (DME) and stir vigorously to dissolve.  Return to heat and resume boil.
6. Add 1.5 oz. Cascade Hops for bittering.
7. Boil for 40 minutes.
8. Add remaining 2 pounds Light Dry Malt Extract (DME).
9. Add 1 Whirlfloc tablet (an Irish Moss product).
10. Boil for 15 minutes.
11. Add 1.5 oz. Cascade Hops for aroma.
12. Boil for 5 minutes and terminate boil.
13. Chill wort to 70 degrees or less and transfer to primary fermentation (strain).
14. Take OG reading with hydrometer - target is 1.056.
15. Optional - add water to get OG to target range.
16. Pitch yeast.
17. Ferment in primary for 4-7 days.
18. Take second specific gravity reading.
19. Move to secondary fermentation for an additional 10 days or more.
20. Take final specific gravity reading.
21. Prepare priming sugar and add to bottling bucket.
22. Transfer wort to bottling bucket and bottle.
23. Bottle condition for 30 days.

Notes, Results and Lessons Learned:

• Brew Day - December 5, 2011
• Stop watch quit working for initial 40 minute boil so had to estimate.  Not too concerned.
• Yeast starter seemed to work well.  Lots of activity within a couple of hours.  I was a little concerned that the activity in the yeast starter had ceased before I pitched it but it didn't seem to matter.  Pitched the whole starter - did not drain off wort beforehand.
• Transfer to secondary fermentation - December 12, 2011 (7 days in Primary)
• Forgot to add the airlock floater for about an hour.  Hopefully no contaminants reached the beer.
• Bottling Day - December 24, 2011 (12 days in Secondary, 2 days longer than planned)
• Fermentation temperature (range) - 61-66 degrees.  Would have preferred a constant 68 degrees but since fermentation was done in the basement I could not control it.
• Estimated Original Gravity - 1.056
• Actual Original Gravity 1.068!  Did not add water at end of boil to adjust.  Consider doing a 6 gallon full boil next time.
• Estimated Final Gravity - 1.012
• Actual Final Gravity - 1.020
• Took a specific gravity reading when transferring to secondary fermentation and got a reading of 1.020.  The sample contained a fair amount of trub so I don't know how accurate it was.  This would translate to an ABV of 6.3% or .5% higher than expected.
• Estimated ABV - 5.8%
• Actual ABV - 6.3
• Priming sugar may have carmelized.  I dumped all 5 ounces in the boiling water and it clung to the bottom a bit.  It broke up and seemed fine but wonder if it will affect the taste.
• Next time I need to remove from heat and slowly stir in to water and then return to heat.
• Remember to aerate the wort well when pitching the yeast.  Full boils will lessen the oxygen in the wort which is needed to fuel the yeast.
• Pitched yeast, covered carboy with sanitized aluminum foil and shook vigorously.  This seemed to have worked fine.
• I'm going to try and perfect this recipe before moving on to a different recipe/style.  Main objectives for Batch #8:
• Start with a pre-boil water level of 5.7 gallons as prescribed by BeerSmith.
• STRAIN this batch!
• Consider using a blow-off tube.
• Use the hydrometer and keep your results for reference.
• Aerate well.
• Pay close attention to fermentation temperatures - keep them constant.  Shoot for 67-68 degrees.
• This style probably does not require a yeast starter as the specifications on the Wyeast site indicate it can handle a full batch based on my style stats.  Follow these instructions carefully.
• Don't be so anxious to transfer to secondary.  Let the yeast do it's job.  Use a hydrometer to assess when/if it is time to go to secondary.

The Verdict:

• Opened a bottle at 13 days and was disappointed that it was not more carbonated.  It also had a sweet taste which probably indicates the yeast did not fully do it's job.  It may still come around with more time.  Additionally, the area where it was bottles conditioned dipped into the 50's which may have made the yeast go dormant.  I brought 4 bottles upstairs where the temperature is more stable and agitated them on a daily basis for several days to try and get the yeast going again.  Time will tell...