How to brew a great lager!
For the most part home brewers tend to start out brewing ales and stick to them since ales ferment faster, tend to be a bit more versatile than lagers and do not require you to keep your home at the temperature of a morgue if you want to ferment your beer in your closet. Not to mention, most home brewing supply shops tend to release far more ale recipes than lager recipes and relatively few craft breweries even have a lager in their beer lineup.
So why brew a lager? Because lagers are awesome! They are crisp and clean, delicious to taste and beautiful to look at! In fact, some of the worlds best beers are lagers. Not to mention, lagers were session beers before session beers were even a thing, which means you can throw back a few lagers while brewing a batch of beer and not be so tipsy that you forget to add your hops to the brew kettle or pitch your yeast in the fermentor. And do not go thinking that a lager has to be some low IBU (International Bittering Unit) grandma beer. Several breweries have been crafting beers like IPL’s India Pale Lagers and other non traditional lager styles that will make you rethink what a lager is.
Now that we have that squared away, lets start at the beginning. What is the difference between a lager and an ale? Lager is the German word meaning storage or to store. As in, “Kann ich bitte lager meine Essiggurke in Sie” or “Can I please store my pickle in you”. The Germans called a lager a lager because they would cold store the beer for several weeks as it fermented and after it fermented, creating an exceptionally clean and crisp beer. That does not mean that you can just place your ale in a closet for 6 weeks and all the sudden have yourself a lager. A lager is fermented with a lager yeast as opposed to an ale yeast. Lager yeast is different from ale yeast in a few ways. For one thing lager yeast conducts most of its fermentation at the bottom of the fermentor as opposed to an ale which does so at the top of the fermentor. Most importantly is the temperature at which the fermentation occurs. While the ideal fermentation temperature for most ale yeast strains is right at about 68 F, the ideal temperature for most lager yeast strains is about 50 F, which means you better buy a jacket with your lager recipe kit if you are going to ferment in your living room.
So how do you brew a great lager? To start with, you are going to need a great recipe kit. Lagers can be pale or dark, do not let all of the typical mass brewed American lagers skew your understanding of what a lager is or can be. A couple of great lager examples are Vienna lagers which are a beautiful amber color with a rich malty taste and a Munich Helles which has a pale golden color with a mild bitterness.
You can find some great lager home brewing kits here: Home Brewing Recipe Kits
Next you will want to select the ideal yeast strain for your style of lager. You can find a fantastic selection of lager yeasts here. If you can not decide which to go with, the Munich 2308 is usually a safe bet. You can pitch these yeast packages directly into your fermentor but I recommend that you create a yeast starter for a few reasons. Most importantly it will allow you to confirm that the yeast is alive and healthy, it will allow the yeast to return to an active state so that it can begin reproducing and fermenting immediately when placed in contact with your lager wort and lastly it will boost the yeast cell count to help insure a fast and complete fermentation takes place.
If you do not have access to a fermentation chamber such as a temperature controlled chest freezer, refrigerator or fermentor setup such as this one Brew Bucket Temperature Controller, you will want to make sure that you brew your lager during a time of the year where the average temperature that you ferment your beer will be approximately 50 F. If it is much colder than that your fermentation process will slow to a crawl or cease all together, if it gets much higher your lager will ferment to fast and is likely to create unwanted off flavors . You can also use items like an electric blanket and a temperature control unit such as this one Ranco Digital Temperature Controller, to help regulate your fermentation temperature. Consult your specific lager yeast strain packing to find the ideal fermentation temperature as they can differ. Keep in mind that patience is a virtue when it comes to brewing a lager and if you take your time you will more than likely be rewarded with a better beer!
In order to create the best tasting lager possible you will need to reduce or eliminate one of the more common off flavors in a lager which is diacetyl. To do so, you should perform a diacetyl rest at the end of your primary fermentation. Dicaetyl is described as tasting like butter and some popcorn manufactures use it as an artificial flavor for their microwave popcorn. While it may make your popcorn taste better, it should be avoided in your lager and is something that your yeast will produce during fermentation. The good news is that your yeast can also remove it! If at the end of your primary fermentation you allow your fermentation temperature to increase from 50 F to 55 F for a few days, the yeast will naturally begin to eliminate the dyacetyl from your beer. After the three days you will want to reduce your fermentation temperature to 50 F once again.
One of the most important characteristics of a lager is its clarity and brightness! For that reason, I suggest that you conduct a 2 stage fermentation and “lager” or store your beer in a secondary fermentor after primary fermentation has completed and the yeast and solids have consolidated on the bottom of your fermentor. Primary fermentation will typically have completed in about 3 weeks or so but take gravity readings to be sure. Racking your beer off of the expended yeast, residual hop matter and fallen proteins will also help prevent off flavors from forming in your lager as your beer ages in the secondary fermentor. I would suggest allowing your beer to age for an additional 2 to 4 weeks in secondary fermentation. During the final week of secondary fermentation I will typically cold crash my fermentor down to 38 F which encourages any fine particulates and residual yeast cells to drop out of the beer and consolidate on the bottom of the fermentor. I then rack the beer to a keg and let it slow carbonate and condition for another week or so before enjoying!
Best of luck to you in brewing your lager and let me know if you have any suggestions that you would like to share with other West Coast Brewer visitors!