Yeast 101

yeast vials

There’s an old saying that brewers make wort and yeast makes beer. And you can’t argue with that. All your hard work, calculating, measuring. adding ingredients and cleaning, you’ve really only done one thing – created the perfect breeding ground for yeast. Lucky for us, the byproduct of a yeast orgy is alcohol or this whole process would be kind of pointless.

On a very high level, there are two types of yeast – ale and lager. Beyond that. there are tons. There a many strains from quite a few vendors and all have their own unique traits. Some will finish dry and crisp, others will have spicy or floral notes. For pretty much every style of beer there is at least one strain of yeast that’s been developed specifically for it. You could write books on just yeast alone (and people have) but for our purposes, we’ll keep it fairly basic.

Using yeast can be complex, but in all honesty as a homebrewer, it only has to be as complex as you make it. Many strains come in pitch ready packs so you can just open and dump into your fermentor. If you want more control, you can make a starter or try to cultivate your own strains. But we’ll get to that later.

ale yeastAle Yeast

This is probably what you’ll use most often, especially if you’re a new homebrewer. Ale yeasts are top fermenting, meaning   they live at the top of your wort. They thrive at room temperature (65-72) and can also work a bit out of that range. Ales are a homebrew staple as a lot of us don’t have the equipment or space to lager.



lager yeastLager Yeast

Lager yeast can live at much lower temperatures (into the 40s) than ale yeast. They are the opposite of ale yeasts as they are bottom fermenting. Lager yeasts can be used in ales, but ale yeasts can’t be used in lagers. If you do use a lager yeast in  ale, you might get some flavors you weren’t expecting. Sometimes that’s good, other times bad. If you’re planning on trying this, check around first and see if anyone’s tried what you’re thinking about and see what the outcome was.



Pitching is name for when you add your yeast to your wort. For both ale and lager yeasts, you want to cool your wort down to about 68. You can go lower for lagers, but some brewers will start here and then drop the temp to help speed up the process. The lower the temp, the longer fermentation times will get. Ales are usually done in the primary between 4-7 days and lagers more around 10-14.


Regardless what kind of yeast you’re using, aeration is good at this point of the brewing process. I have an oxygenation pump that I use for about an hour before I pitch. I also always use a starter, so I’m getting a strong concentration of yeast cells in the wert. I usually see activity in the frementor within a few hours.

If you’re using a glass carboy, you’ll be able to see everything moving around once fermentation starts. If you’re not, just keep an eye on the air lock. You should see it bubbling within 12 hours at the most, reaching that time period at lower temperatures for lagers. If that doesn’t happen, you might have stuck fermentation or your yeast might be bad. But we’ll cover all that in a later post. Cheers and happy brewing

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