How to Make a Yeast Starter

There are many different processes and methods that homebrewers use to make a yeast starter so I am going to tell you my method and some of the reasons why it works well and other tidbits that may help you understand what you are doing and why you are doing it.

First of all you will need some additional equipment that you may or may not have and you can choose what type you will want to invest in.

• A vessel to ferment your starter in. It can be an Erlenmeyer flask that you can boil on the stove or it can be as simple as a glass jug that can be had for free (this will require a separate vessel to boil in)
• Tinfoil
• An O2 system that will allow you to introduce oxygen in your starter wort
• Yeast nutrient
• Stainless steel boil vessel (2-6 qt depending on the size of your starter and optional if you have an Erlenmeyer flask)
• Funnel
• Dry Malt Extract (DME)….
• Spray Bottle filled with StarSan (optional but very handy)
• Stir-plate and stir bar (optional)

Why Make a Starter?

Why make a starter when a vial or smack pack would do? The first thing is that although the yeast suppliers tell you that one vial or smack pack will ferment 5 gallons, they don’t tell you that the optimal amount of yeast cells for fermenting 5 gallons is considerably more that what is in one vial or smack pack. This is the reason for making a starter, to pitch the optimal amount of yeast for a given quantity of wort. There is also the idea of brewing a beer and pitching on a yeast cake from a previous batch. Just like a vial or smack pack will ferment 5 gallons so will pitching on yeast cake, still doesn’t mean that you are pitching the optimal amount of yeast cells for your batch. You wouldn’t add an extra 6 lbs of DME to a batch that calls for only 6 lbs so why would you pitch two or three times the yeast that’s needed for a batch. So how do we figure out how much yeast to pitch and how big a starter to make? Fortunately a renowned homebrewer named Jamil Zainasheff has taken the time to bypass all the microbiology classes needed to figure this out and has put out a pitching rate calculator that is available online at http://www.mrmalty.com/calc/calc.html

A Few Basic Notes

Ales vs. Lagers…..Lagers will require about twice the amount of yeast cells than Ales do. Sometimes you might have to step up your starter to get the proper amount.

DME……Why use Dry Malt Extract vs. sugar or honey? The reason to use DME over other fermentables is to get the yeast acclimated to the environment they are going to be in and to build strong and healthy cell walls and membranes. You wouldn’t put your freshwater fish in a saltwater tank so don’t put your yeast in an unhealthy environment.

Airlocks…..Airlocks are not needed when making a starter, they actually impede the process. The whole idea is to allow oxygen uptake during the process, especially if using a stir-plate. Use aluminum foil as this will eliminate the bacterial ring that will form where the stopper meets the glass. If you must use a stopper, use a foam stopper and don’t forget to flame the lip before pitching.

Sanitation….Use proper sanitation procedures as you don’t want to introduce unwanted nasties into your starter. That’s why I keep a spray bottle of StarSan on hand, as I can always just give it a spray if necessary. It also requires no rinsing and when it breaks down it is actually a yeast nutrient.

OG of a Starter…..The OG of your starter should be between 1.030 and 1.040….there is no need to make high gravity starter when making a high gravity beer as long as your pitching rate is of the proper amount. You don’t want to stress the yeast out during the starter process.

Dry Yeasts…..Dry yeast is intended to be pitched as is. Starters are not recommended when using dry yeasts but it may take more than one pack to pitch the proper amount of cells.

How I Do It

When making a basic starter for an ale with an Original Gravity of 1.040 I will need to make a starter that is right at 1 quart in size. The amount of DME needed is about 3 ounces per quart. I used to use an Erlenmeyer flask but seeing they are prone to boil over I just use a small stainless stockpot to boil my DME in. I add the 1 quart of water to my stockpot, the DME and 1 teaspoon of yeast nutrient. Bring it to a boil and boil for around 15 minutes and cool in a sink of ice water to the desired pitching temperature. Sanitize the outside of the stockpot with a few sprays a StarSan, and pour into the sanitized flask using a sanitized funnel. Next I will shoot about 15 seconds of oxygen from my sanitized O2 set up into the wort and then pitch my yeast. I then cover the starter with a piece of sanitized aluminum foil and put it in a place that will keep it until the desired time to pitch……it will be ready in 12-24 hours so making your starter the night before you brew is good way to go about it……..SO EASY A CAVE MAN CAN DO IT !!!!......................

One thing that will help with increasing cell count is using a stir plate but if you don’t have one give your flask a swirl every time you get a chance to help keep the yeast in suspension and help with O2 uptake.

For more detailed information read up on making starters at:

Proper Yeast Pitching Rates

Yeast Propagation and Maintenance: Principles and Practices