Have you ever tasted a beer that was sickeningly sweet, tasted like band-aids, smelled and tasted like fake butter, or had a muddy unfocused character? I sure have. While we have had beers that exhibit these characteristics at Kettlehead’s meetings, I am surprised at how many commercial beers exhibit similar characteristics. What causes these flaws and what can we as brewers do to prevent them?

While there are a few things that could cause these characteristics in a beer (poor sanitation, poor brew day practices), one of the easiest control points that can help eliminate these problems fermentation. A healthy fermentation consists of proper pitching rate, fermentation temperature, and fermentation time. Without paying attention to these key fermentation factors you are rolling the dice on the quality of your home brew.



Pitch Rate

Pitching the proper amount of healthy yeast is critical to a healthy fermentation. Healthy yeast can cover up a multitude of brew day sins, including poor sanitation. If the right amount of healthy yeast is pitched the yeast will rapidly reproduce and overwhelm any bugs or wild-yeast that may have gotten into the beer between boiling and racking the beer to the fermenter.

Pitching too few yeast cells not only risks the chance of allowing unwanted bacteria to flourish, but also stresses the yeast causing them to produce unwanted flavor and aroma compounds in your beer. My first year of brewing I had about 6 batches that all contained an off-flavor that ruined the beer. After tightening up my sanitation and trying a few other possible solutions, I eventually identified the cause of the problem: I was pitching one vial of yeast into 3 gallons of 1.060 O.G. beer. I began making yeast starters, and the off flavors disappeared.

Calculating pitch rate may have been tricky in the early days of home brewing, but brewers now have a variety of tool to help them know when to prepare a starter and how big of a starter to make. The easiest to use it Mr. Malty’s Pitch Rate Calculator. Simply plug in your estimated O.G. and volume and the calculator tells you how many vials you need and what size starter is appropriate.

I am not going to go into detail on how to make a starter – there are other resources that can explain it better than I can. One of the following links is a great way to start:

Mr. Malty  |  How to Brew


Dry Yeast

An alternative to using liquid yeast and creating a starter is to use dry yeast. Some people avoid using dry yeast because of perceived lack of quality, which is not true. Modern dry yeast can produce excellent beer. The only drawback to dry yeast is that there is not as wide of a variety of yeast strains as with liquid yeast. I like to use dry yeast whenever possible because it is about half the price of liquid yeast.

An 11 gram dry yeast packet has more yeast cells than a vile or smack pack of liquid yeast, just make sure you are using an 11 gram packet and not a 5 gram packet. If you do decide to use liquid yeast, make sure you rehydrate the yeast properly. If you simply pour the yeast from the packet into your fermenter, half of the yeast cells will immediately die once they hit the beer. Dry yeast must be gently rehydrated to maintain cell count for a healthy fermentation. To rehydrate yeast properly, follow the directions listed on the How to Brew website.



Up Next: Fermentation Temperature