Warm Fermented Lagers

by Steve Thanos | Updated: July 17, 2019

Lager is type of beer fermented at low temperatures. Warm fermented lager is a beer that is fermented at the temperatures you would normally ferment an ale.

This is usually between 65°F to 68°F (18°C-20°C).

Conventional wisdom tells us that there are certain rules in place when brewing a lager. Fresh ingredients are a must, there is nothing to hide behind when brewing a lager, and finally and maybe most importantly temperature control is a must.

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Grains ready for brew day.

What the Experts Say

Brew Your Own magazine published an article a while back entitled, 10 Keys to Great Lager.”

1. Remember, patience is a virtue
2. Control temperature well.
3. Use a true lager-type yeast.
4. Use a yeast starter.
5. Use Irish Moss and a vigorous full-wort boil.
6. Use a wort chiller.
7. Use a two-stage method of fermentation.
8. Incorporate a diacetyl rest into the fermentation.
9. Select appropriate ingredients for the style of lager you are brewing.
10. Sanitize.

Following My Dogma

I was always taught and have read that ales are usually fermented at 65°F to 68°F (18°C – 20°C) and lagers at 48°F to 55°F (8°C – 12°C).

Many for years have believed and preached that creating beer just a few degrees warmer produces fruity esters or spicy phenols. Fermenting even higher will almost certainly produce fusel alcohols.

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Fermentis Saflager W-34/70 known for its ability to ferment warm.

I have always loved brewing and drinking ales. I am a huge fan of IPAs, Pale Ales, Red Ales, Brown Ales, Porters, and Stouts. For the longest time due to fermentation limitations, I was only brewing ales.

With that said, I also enjoy most things lager. A nice Pilsner, Märzen, Schwarzbier are some styles that I enjoy a great deal.

A few years ago for Christmas, my wife bought me a 5-cubic foot chest freezer. I was able to finally brew a lager with controlled temperatures. Lagers were soon to be on my brewing horizon.

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Abby and Pinot pay me a visit on my brew day.

Knowing Your Brew “House”

Over time, I have begun to know the temperatures in my house that is right for brewing. In the spring and summer months, my crawl space reaches 68°F (20°C) give or take a few degrees.

My dining room reaches around 68°F (20°C) in the fall and winter months. When I am not fermenting in my chest freezer, I am looking to these two places to house my carboys or buckets for a couple weeks.

I decided to take all of this wisdom and throw it out the window when choosing to brew a warm fermented lager. Having followed most of these “rules,” I am curious as to how this beer would turn out if I fermented it at ale temperatures.

When I brewed this beer a couple weeks ago, the summer temperatures were in full swing. With temps reaching 90°F (32°C), and the temperature in my crawl space at 68°F (20°C), I knew I found a perfect place to house my beer.

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Crawl Space temperature at 68°F (20°C).

Dad Joke – Red Rye Lager Recipe

Malt

• 57% 3 lbs Pilsner
• 29%. 1.5 lbs Rye
• 9% .5 lb Red X
• 5%. .25 lb. Pale Chocolate

Hops
• .5 oz Brewer’s Gold. 60 min. 7 AA 22.5 IBU
• 1 oz. Comet 5 min. 9.5 AA 9.5 IBU
• 2 oz. Comet Flameout 9.5 AA
• 2 oz. Comet Dry Hop 9.5 AA

Yeast
• Fermentis Saflager W-34/70 83% Attenuation

Batch Size: 3 Gallons
Boil Size: 5 Gallons
OG: 1.048
FG: 1.008
Color: 12.2
Efficiency: 75%
Bitterness: 34.7 IBU
Alcohol: 5.2% ABV

The Verdict…Drumroll Please

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Pulling a sample.

Upon taking gravity readings and prior to dry hopping, I took a taste of this beer. It was clean, dry, crisp, a distinctive bitterness, and without any noticeable off-flavors.

I am kicking myself for the years of not trying this yeast prior to owning a fermentation chamber. I guess a late lager is better than no lager at all.

I am the former President of my homebrew club, Plainfield Ale and Lager Enthusiasts (PALE) in the western suburbs of Chicago, IL. I brew on my BIAB system with my incredibly patient and understanding wife, adorable 9 year old daughter, and 12 year old brew dog.