Taking your home brew to the next level requires some upgrades in your brewing process, and one of the most essential upgrades needs to be your yeast.
If you are brewing a strong beer, or would simply like to ensure that there is enough yeast to ferment your brew, the cheapest and most effective way to do so is with a yeast starter.
1. What is a Yeast Starter?
A yeast starter is a mini-batch of wort that is prepared to help yeast activate and multiply before being added to an actual batch of wort. A small batch of light dry malt extract is boiled and cooled, then a packet of yeast is added and allowed to grow for a day or so.
You can read an Introduction to Yeast Starters Here.
2. What Are the Benefits of a Yeast Starter?
There are at least five huge benefits to using a yeast starter:
1. A yeast starter will help yeast multiply so that there is a sufficient number of yeast cells to perform the fermentation, especially when brewing a stronger beer or a higher-volume batch.
2. Have you ever checked the manufacture date of your yeast? The older it is, the less viable the yeast cells are. If yeast is getting old and is less healthy (less viable) than usual, a yeast starter will bring it back up to strength.
3. Yeast will take action faster when added to the wort, limiting the chances for other microbes to take over and infect the beer.
4. While the same effect of raising yeast cell count can be achieved by buying two packages of yeast, the yeast starter will give the yeast a little bit of a kick-start and reduce the “shock” of being pitched into the environment of a strong batch of wort.
5. The boosted yeast cell count and the kick-started yeast will accelerate the fermentation process.
3. When Should I Use a Yeast Starter?
There is rarely a time a yeast starter will not serve a brew well. A yeast starter is not always necessary when brewing lower-gravity (less alcoholic) beers, but it still brings benefits that will improve the beer.
In many cases a yeast starter is crucial. Brews with an expected original specific gravity of 1.060 or higher require a yeast starter to provide sufficient yeast for fermentation of such a strong brew.
Many brewers actually swear by yeast starters on any beer with a starting gravity as low as 1.040. Some home brewing stores say that all of their employees use a yeast starter for every single batch that they brew.
4. When Should I Not Use a Yeast Starter?
It is safe to pass on a yeast starter for an especially small batch of beer or one that has a low starting gravity. In these cases, adding too much yeast might cause the formation of some off-flavors.
When dry yeast is used for fermentation (as opposed to packets or vials of yeast in a solution) it is actually cheaper to just buy more packets of dry yeast than to buy the necessary ingredients for a yeast starter. Dry yeast does need to be activated in water before pitching it into the wort, but this is different than making a yeast starter for it.
5. What Volume Should My Yeast Starter Be?
The volume necessary for your yeast starter depends on multiple factors including the batch size and starting gravity of your beer and the age of the yeast you are using. In general the liquid yeast that you buy from the local home brewing supply store can be sufficient for a five gallon batch up to a starting gravity of 1.060 if the yeast is relatively young.
It is important to remember that the viability of the yeast (essentially, its health) decreases rapidly. If your yeast package was produced a month ago it is only 75-80% viable, meaning it has lost 20-25% of that original fermentation power.
There are formulas that will help determine the proper starter size after taking these factors into consideration, but we recommend using the handy MrMalty.com Calculator to make this process a lot easier.
Most home brewing supply stores sell yeast starter kits in both a One Liter size and a Two Liter size. Some supply shops even sell yeast starter kits in a Five Liter size. We have found a two liter yeast starter kit to work well for most everything that we brew.
6. What Specific Gravity is Ideal for a Yeast Starter?
Even if brewing a beer with a very high starting gravity a strong starter wort is not ideal. Create a starter wort with a gravity of between 1.030 and 1.040. Wyeast Labs, one of the two big producers of brewers yeast, recommends a gravity of 1.040 for yeast starters.
The idea is to create a starter that makes it easy for the yeast to activate and start multiplying. Creating a starter that is too strong might actually overwhelm the yeast and prevent it from becoming stronger.
7. How Do I Make a Yeast Starter?
If you are unsure about the details of making a yeast starter check out our post about that (with video) Here.
Want to learn how to enhance your yeast starter? Read more Here.
Want to learn more about yeast in general? Check out this book.