Lagering question

[tacks]

I've been brewing for about a year and a half now, and have never had the equipment to lager, but my brother whom I recently got into brewing now has the setup, just needs to hook up a temp controller. Most questions I can answer for him either from reading up on brewing or stuff I've run into here on HBT. The other day, he asked me one that stumped me though,maybe someone here can answer. It's there a reason that heavy, dark beers don't get lagered? I'm assuming it has to do with lager yeast not being able to tolerate high alcohol environments, or high levels of unfermentable sugars in darker beers that are mashed at a higher temp?

 

[trboyden]

I guess only if you don't consider German Bocks to be dark heavy beers?

For the science of ale yeast versus lager yeast, I'll point you to this Popular Science article: http://www.popsci.com/science/article/2013-01/beersci-what-difference-between-lager-and-ale

To summarize, there are two main differences to ales and lagers. The first is ales are fermented warm and lagers are fermented cold. This causes lager yeasts to ferment slower, though there is ways to speed this up by starting them at 60F for the first 24 - 48 hours. The second difference is the flavor profile left on the final beer. Ales tend to be more fruity/estery (more yeast influence in the flavor profile), and lagers are crisp, with more of the grain and hop influences coming through in the final flavor profile.

Lager yeast is actually a hybrid of ale yeast and a South American variant that gives it its cold fermenting properties.

So technically speaking, there is nothing to stop you from lagering a stout, no matter the strength. It's just not to BJCP style guidelines.

Two technical items to consider - 1) you'll need double your normal yeast count for a ale stout (so if you use one ale yeast packets, you'll need two lager yeast packets), and 2) you'll need to plan for a longer fermentation/lagering process in your brew schedule.

 

[TopherM]

Baltic Porters are typically close to double digit ABV, and are made with lager yeast and lagered. I have one at home that comes in at 9.9% ABV, looks like motor oil, and has a crisp, clean lagered aftertaste!

 

[Cyclman]

I have lagered numerous dark beers. The cleanness makes for wonderful roasty, chocolate flavors. Highly recommended.

 

[tacks]

Thanks, all. Have never looked at bock recipes, to be honest didn't know they were lagers. My book on yeast is due to be delivered tomorrow, so I can edumacate myself on proper yeast use according to style. Thanks for educating me, looking into lagering now that it's an option. Happy brewing to all and to all a good night!