If you brew regularly with liquid yeast, starters are a fact of life. Having a dedicated yeast kit ensures that everything you need to build a starter is in one place and ready to go. This can also be useful when brewing with friends or at different locations so that the yeast kit can be taken easily to another house or location to build the healthy yeast, then transported back when ready to brew. It also sucks to be in the middle of making a starter only to realize you forgot to grab the yeast nutrient or lost your stir bar.
While we might dig more into the steps for making starter at a later time, you can already find a lot of information on the internet about that process. You can also see White Labs website for information on creating starter. You can calculate your own starter recipe by using the BrewUnited Yeast Calculator. Let’s look briefly at the process so that we understand the considerations when making an equipment kit.
Do not get overwhelmed if you’ve never made a starter before. While there are a lot of details and minutia, for the most part it’s a simple process and after you do it a couple of times, it ends up being really straight forward. Making a starter consists of a few main steps:
- Creating a sterile starter wort to around 1.040 gravity
- Chilling the wort to pitch temperature (around 70 degrees)
- Fermenting the starter in a consistent environment
- A small portion should be harvested for later use (optional, but do it)
- The remaining starter can then be pitched directly or first cold-crashed/decanted to remove some excess liquid
The starter wort should not contain any other contaminants that may affect the yeast growth and needs to contain all the nutrients for the yeast to be healthy and reproduce. A yeast nutrient adds extra minerals and nutrients that might not already be included in the DME typically used to make the starter wort. This ensures that the yeast are at their peak fitness when they are pitched into your brew day wort. Additionally, the starter wort should be boiled for a few minutes before pitching yeast into it to ensure that no other organisms have a head start on the yeast for colonizing the starter wort.
Since the wort needs to be boiled, chilling the wort quickly is paramount to the success of a starter. The longer it takes for the wort to be chilled, the longer time there is for other contaminants to infect the starter. The wort must be chilled down to almost the same temperature that it will ferment at, a few degrees different is just fine. Additionally, the yeast packet purchased from the store should be warmed up a couple of hours ahead of time so that it’s also near the chilled starter temperature. This is so that the yeast don’t get shocked when being pitched into the starter.
Once the yeast has been pitched into the starter wort, it should be kept at a constant temperature as much as possible. The higher the temperature, the more the yeast are stressed and won’t be at necessarily be peak health for making your final beer. The lower the temperature, the longer the starter will take to finish. Additionally, the best starter is covered in (sanitized) foil or some other means of allowing for air to exchange with the wort while keeping out contaminants. Airlocks are typically not used since these do not allow fresh air to interact with the wort. Because of this, care must be taken to not accidentally contaminate the starter or remove the foil cover.
These are items that don’t get stored in the kit but are necessary to make the starter:
- Yeast – This shouldn’t need an explanation.
- Ice – To cool the wort quickly. Ice packs would also work just fine.
Hopefully they are obvious but for completeness, they need to be mentioned.
We consider these items essential for a yeast kit. Without this equipment, it will be very difficult to make a healthy, uncontaminated yeast starter.
- DME – It’s always good to have a backup bag on hand as well, just in case.
A box – We use a Sterilite 7.5 gallon Modular Stacker for our kit box. Any kind of study storage box that’s the right size to fit your yeast kit equipment and still be mobile will work.
- Scale – This is needed to measure out the ingredients.
- Heavy-duty Foil – Used as a cover to the flasks and beaker during chill and ferment.
- 2 L Erlenmeyer Flask – This glass allows direct heat to ice bath transfer without breaking. Flat bottom allows for easy stirring with a stir plate.
- 500 mL beaker or 2 cup mason jar – Having a beaker or two around allow you to measure amounts of liquid quickly and accurately, pour off liquids into something that can be sanitized easily, and cold-crash harvested yeast slurry to later put into library storage. Mason jars can also be used for long term yeast library storage but it’s not recommended since the metal lids corrode easily and can contaminate the yeast. Use soda preforms instead.
- Star San – Kill all the things!
- Spray Bottle – It’s very difficult to completely cover a surface with Star San without a spray bottle.
- Scissors – Most yeast are easier to cut open cleanly.
- Empty sink (for ice bath) – The wort needs to be cooled quickly.
- Thermometer – The temperature is important at various stages, including the temperature of the flask (for sterilization), the temperature of the chilled wort (for pitch temperature), and the temperature of the fermenting wort (for optimal yeast health).
- Funnel – Erlenmeyer flasks have small openings.
- Disposable gloves – These are clean, cheap, and easy to deal with.
Labels or masking tape – When handling many different yeast samples, it’s important to keep track of which sample is in which flask.
- Permanent marker – Things get wet. Permanent markings are good.
Nice To Haves
Here are some other things that can make your starter experience much easier, and make the yeast happier.
- Yeast nutrient – Very beneficial for creating and maintaining a healthy yeast starter. This has minerals like zinc which the DME usually doesn’t contain and can affect your yeast growth rate quite a bit. The Wyeast yeast nutrient is at my LHBS for $3 or $4. You can certainly make a starter without it, but you’re going through the effort to make healthy yeast, so why not?
- Fermcap-S – Prevents the starter wort from boiling over. This can also be used on brew day to prevent your kettle from boiling over.
- Stir plate – Get or build one. Your yeast growth rate increases drastically when using a stir plate versus letting the starter sit still or occasionally shaken.
- Stir bars – A stir plate doesn’t work without a stir bar. Make sure to have some backups on hand as well since these are easily lost, and different sizes work better or worse depending upon the ferment container and volume.
- Strong magnet – For sticking on the outside of the flask to capture the stir bar, so that when pitching the yeast the stir bad doesn’t end up in your brew day wort.
- IR Thermometer – An IR thermometer is great for a starter since you want to interact with the wort as little as possible to avoid possible contamination. An IR thermometer allows you to get fairly accurate temperatures without needing to touch the wort liquid.
- Ove’ Gloves – Many knock-off’s are available cheaply on Amazon. These types of glove are heavily insulated which allows you to handle hot pans and flask, as well as having silicone grip so that things don’t slip when you are holding them. The are machine washable and fantastic addition to not only a yeast kit, but a brew kit as well.
- Soda preforms – For yeast library storage. These little containers are cheap, high-pressure safe, don’t rust or put affect the liquid being stored in them, and take up very little space. You’ll likely want to pick up a rack to hold them as well.
- Whisk – DME is messy to deal with and tends to clump up easily. This can help break up the clumps and fully incorporate the DME with the wort.
- Transfer/graduated pipettes – For measuring samples and Star San
- Refractometer – Far better than a hydrometer since it only requires a few drops to measure gravity. It’s not necessary to measure your starter wort gravity but it’s a good sanity check to make sure it was correctly mixed.
- Large bowl, bucket, sink, or dish tub – One or two of these are useful since they can be filled with Star San solution to dip various equipment or hands into, as well as filling with water and/or ice for chilling the starter to pitch temperature.
- Fermentation refrigerator – Makes it easy to maintain a proper temperature without worrying.
- Flask top and airlock – Sometimes, an airlock can be good for certain kinds of starters (such as lactobacillus). This isn’t necessary especially if you are not going to be doing lacto starters.
Bring It All Together
Assemble your kit into your storage box. Do not remove items from it unless you put them back immediately after using them. Keep the yeast kit equipment as dedicated as possible. We have duplicates of things like yeast nutrient that might also be used in our normal brewing processes so that we can keep one of them dedicated with the yeast kit. You can print an inventory list and tape it to the inside of the lid so that you can confirm all the contents are there before and after you need to make a starter. Once you have your kit assembled, you’ll always be prepared to create a yeast starter and never be caught off guard again.