You don’t need to be a master brewer to know that without yeast, we wouldn’t have beer. Basically, yeast are single-celled organisms that are a type of fungus. A yeast cell is about the same size as a human red blood cell. The most common yeast strains are used for brewing and baking, and obviously for our purposes we are looking at the brewing kind.
When talking about yeast for beer, there are two major camps: ale and lager yeast. Basically, ale yeast is top-fermenting because it rises to…you guessed it…the top when it ferments. Top fermenting yeast works best as relatively warmer temperatures, and is used in beers such as ales, porters, wheat beers, and stouts.
Bottom-fermenting yeast is known as lager yeast because it is used in lager-style beers. As you can probably guess, lager yeast ferments on the bottom as fermentation nears completion. These strains of yeast tend to work at lower temperatures, which is great for the layering these beers generally go through. Beers that use lager yeast include: Pilsners, bocks, and Dortmunders.
The purpose of this post isn’t to explore the intricacies of lager versus ale yeast, or to even go into the finer points of these beers. These topics have been covered in other posts. This post is meant to show the different delivery methods you will come across when home brewing. There are many different styles of yeast, and multiple methods of storage and delivery to get the yeast into your beer. Let’s take a look.
Liquid vs Dry
The first big distinction here is if the yeast you are using is liquid yeast or dry yeast. It’s pretty easy to tell which is which when you buy your yeast, but you may not know what the finer details are.
Dry yeast comes in a vacuum-sealed package that is usually about the size of a large business card. When you open the packet, you should see a lot of tiny, grayish pellets. These are dried yeast cells. Billions of them. Dry yeast is great because it stores easily, and can be stored for longer than liquid yeast. It is easy to handle and you generally don’t need to make a starter (more on that in a minute). The biggest down side to dry yeast is the lack of variation. There are very few strains of yeast that work well when dried, so the only ones you can get are those that preform well. Since yeast is a major factor in taste, this can be less than optimal.
To use dry yeast, you can indeed just dump the packet into the wort, but the ideal method is to re-hydrate the yeast to “wake them up” and give the best chance of their activation and growth in your wort. Not doing this can lead to under-pitching.
You generally find dry yeast in starter kits for home brewing. A great way to step up your brewing with still using one of these kits is by upgrading to liquid yeast. Let’s check that out now.
The Smack Pack
Liquid Yeast comes in a few different delivery methods. The common factor in liquid yeast is that the yeast is alive and well, not dried and in stasis as with dry yeast. The first delivery method for liquid yeast is the Smack Pack. These are from a company called Wyeast. These consist of a sealed “envelope” that contains two packets. The first packet is the liquid yeast. The second contains some yeast nutrient that aids in yeast growth. Basically with these, you lay the pack on a solid, flat surface and smack it, breaking the internal packets, allowing them to mix in the envelope.
These are good because you get the yeast growth before pitching, as well as a sign that you have healthy yeast. The packet will swell as the yeast grow inside it, creating CO2. The contents of one smack pack are used in one 5 gallon batch of wort. These are great because they protect the yeast from light and serve as their own starter (I promise I’ll explain this in a minute.).
The second major form of liquid yeast delivery is the yeast vial. These commonly come from White Labs and include the yeast and some suspension liquid in a vial. These are touted as being “pitchable” from the vial, which they are, but to pitch the correct amount for a 5 gallon batch, you would need up to 4 vials! Instead of wasting your money on that many vials, you can easily grow your own yeast from a single vial. This is known as a starter (I TOLD you I would get to this!). Without getting into the specifics, to make a starter, you basically use Dry Malt Extract (DME) to make a mini-batch of wort that you use to grow the yeast. In other words, you make a mini-batch of beer minus the boil. This gives the yeast sugars to grow, and will give you the proper yeast cell count to pitch whatever size batch you have.
The White Labs yeast vials are extremely popular with homebrewers, as they offer the widest variety of yeast strains. You can view their different ale strains here.
The Importance Of Pitching
Pitching the proper amount of yeast is vital to a good brew. If you pitch too little yeast, you won’t get the Final Gravity (FG) you are looking for, and will probably get some off tastes. If you pitch way too much yeast, you will definitely get off flavors and aromas. Here is a great pitching calculator to help you determine what you should pitch. Also, keep on the lookout for my writeup on making a yeast starter for a 5 gallon batch of beer coming up soon.
Pitching yeast isn’t difficult. If you follow the basic guidelines and understand what style and delivery method to use, you should be good to go.
Until next time,