White Labs Brew Co. collaborated with friends and local brewery, Stone Brewing Liberty Station for a unique science experiment!
From our Head Brewer, Craig’s old connections from Stone, we collaborated with one of his amazing friends. Kris Ketchum, Senior Manager Brewing & Innovation – Liberty Station. Brainstorming together, they decide to use one of our favorite lager strains, WLP830 German Lager Yeast. But instead of choosing another strain, they decided to ferment one at an ale temperature at 20°C/68°F for a Cold IPA. The other was fermented at a lager temperature at 12°C/54°F.
What's a Cold IPA?
A Cold IPA is an IPA fermented with a lager strain at lower temperatures? Or is it an Ale Strain? Or can you take a lager strain and ferment it at higher temperatures?
There are always multiple answers to a question, we took the latter to really distinguish how fermentation temperature effect a beer. As lower temperature slows down yeast growth. Compare it to running in the cold. It takes awhile to warm up and feeling good during the run.
From the colder temperatures and slower yeast growth, we suspect the hops and malt to shine through for a crispier beer. While the hotter temperatures should entice more hop and yeast biotransformation interaction. Unlocking potentials, such as B-lyase activity, an activity that release aroma and flavors notes of guava and passionfruit that were once not present.
What's an IPL? Difference between Ale & Lager Yeast?
By definition, an IPL is an IPA fermented with Lager yeast versus the usual Ale yeast. By what’s the difference between the two?
An Ale yeast, also known as Saccharomyces cerevisiae, is a “top-fermenting yeast”, a lot of craft breweries use these Ale Strains, as they prefer warmer temperatures and have wide strain variety. From Hefeweizen strains, English Strains, to even our favorite workhorse WLP001 California Ale Yeast. There are plenty of strain options under this category.
A Lager strain, also known as Saccharomyces pastorianus, is a hybrid yeast from Saccharomyces cerevisiae and Saccharomyces eubayanus. It was named after famed Zymologist, Louis Pasteur. Just like our Pasteur Porter!
Known for “bottom-fermenting” and preferring colder temperatures. It has been for used styles which made big beer famous as well as throughout the centuries, back when casks were thrown in caves and aged until time for festivities!
But, that's not the only New thing about this collaboration! Don't forget about the hops!
What Hops did we use? HRC-003 & Anchovy? Sounds Fishy?!
We recently used a new hop, HRC-003, is an Elite Line experimental public hop from the USDA breeding program. It’s mother is Brewers Gold and it’s father 64103M. With notes of Peach, Mango, & Tropical, we’re excited to see what hop flavors are impacted on this beer!
Another New Hop, the Anchovy hop from Yakima Valley Hops, Experimental variety 24B-05. Received it’s name from Matt Storm and Brian Strumke from Fast Fashion Brewing in Seattle. Fast Fashion was the first brewery to sponsor acreage for the farm. It’s supposed to impart notes of Watermelon, Raspberry, & Pine!
Fermentation Graph
As expected the Cold IPA at warmer temperatures fermented quicker than the IPL. Because of this dry hopping timelines started around Day 7 for the Cold IPA with a cap and crash at Day 15. While the IPL underwent dry hopping at Day 16 and a cold crash on Day 21.
Flavors/Aroma Graph
Overall, the esters and fusel alcohols were relatively similar from running on our gas chromatograph. The IPL had a harder time cleaning up acetaldehyde at a colder temperature and the Cold IPA had bit more Ethyl Acetate. Although the quantitative results showed little to no difference, it doesn’t showcase the whole difference yeast play at different temperatures.
The best experiment to try is to drink them side by side and see the full picture of tasting notes of raspberries and citrus versus watermelon and tropical!