Imperial Yeast | A10 Darkness Ale | Beer Yeast | Double Pitch | 200 Billion Cells

Imperial Yeast | A10 Darkness Ale | Beer Yeast | Double Pitch | 200 Billion Cells

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  • A10 is loved by brewers for dark beers. Its high alcohol tolerance makes it a go-to for big beers
  • Produces a unique character that matches up perfectly with roasted and caramel malts
  • Double pitch size with a minimum of 200 billion cells—twice the size of the standard yeast pitch
  • Imperial Yeast is a group of hard-working, fermentation fanatics who provide the brewing industry with the highest quality, most effective yeast possible

A10 Darkness is exemplary for use in stouts, porters, browns, as wells as amber ales. Its unique character pairs perfectly with roasted and caramel malts. Due to it’s alcohol tolerant nature, this strain will also work well in high gravity beers.

Attenuation: 71-75%
Flocculation: Medium
Alcohol Tolerance: 10% ABV
Optimum Fermentation Temp: 62-72°F
Cell Count: 200 Billion
Similar Strains: WLP004, WY1084

Please Note: For best results we Always recommend ordering an Ice Pack with your liquid yeast. Ice Packs can be found below in the "You might Also Need" section.

Please Note: When choosing an ice pack option beware that the liquid yeast will not arrive cold even when shipped together. Ice packs and insulated mailing options are designed to keep the yeast colder for longer during shipment, but they will not ensure that your yeast arrives cold. We will not replace liquid yeast that arrives warm. During warmer months we strongly recommend you choose dry yeast.

Item # IYA10
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - In Stock
Weight 0.37 LBS
Community Q&A

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Browse 1 question Browse 1 question
Why did you choose this?
MoreFlavor Store
Excellent yeast
Kevin P on Mar 7, 2023
making beer
James P on Jan 7, 2023
Excellent yeast
Kevin P on Mar 7, 2023
Dry Irish Stout
Christopher G on Feb 14, 2023
making beer
James P on Jan 7, 2023
Last strain died
Chris C on Nov 21, 2022
I am using it as a substitute for A31 Tartan. Have had great success with the Imperial yeasts. Hopfully the A10 will be as good as the A31.
Robert L on Nov 17, 2022
Great yeast for Stout. I love Imperial Organic
Ronald W on Nov 16, 2022
Used it several times on high gravity stouts, this yeast is excellent. With my local store would carry it.
Adam K on Nov 15, 2022
I like strong beer
Eric M on May 18, 2022
First time trying this
Todd J O on Apr 11, 2022
want to brew an Irish Dry Stout
Clive D on Apr 9, 2022
I would prefer to brew as organic as possible
Valued C on Mar 21, 2022
Making a porter
Jared S on Mar 7, 2022
Suggested from friend
Kevin Wilson on Jan 29, 2022
Try it
Neil K on Jan 22, 2022
for a stout
chris k on Jan 22, 2022
Kenneth L on Jan 11, 2022
For my upcoming stout.
Eddie M on Sep 9, 2021
Brewing an Irish Red.
Kyle Heon on Apr 13, 2021
Jeremy H on Mar 3, 2021
Most recommended for stout beer
Pat on Feb 23, 2021
Made a few stouts with it with great results
DANIEL J E on Feb 5, 2021
referred by friend
Mike N on Jan 27, 2021
Imperial yeast is crazy aggressive! Last time I used it, it overflowed a 7 gallon container with 5 gallons of volume, so be careful!
Ashland W on Jan 15, 2021
to make porter
Roy D on Oct 14, 2020
For a big old imperial stout
Clayton H on Oct 1, 2020
Good for mead.
Samuel H on Sep 2, 2020
Excellent experience with the brand
Benjamin B on Jun 13, 2020
Making a chocolate mead and I think the flavors will work well together.
CHRIS C on May 5, 2020
Brewing big high gravity imperial stouts
Quinn H on Mar 25, 2020
For Stout
Jaime E on Mar 17, 2020
Brewing company 30 gallons of beer
Brad M on Mar 5, 2020
PAUL L on Jan 27, 2020
Win P on Jan 15, 2020
seemed like the best selection
Jim H on Dec 27, 2019
can i go now
C H on Nov 23, 2019
I need to brew some dark beers
Michael B on Oct 19, 2019
Cause it's the best
Jason T on Sep 11, 2019
Guinness sourced yeast for my stout pleasure.
John H on Aug 28, 2019
excellent yeast
Ron C on Jul 4, 2019
Made a very good Guinness clone
chris l on Apr 9, 2019
Trying out for a blonde stout recipe being brewed this weekend.
Adam S on Apr 2, 2019
Great performance
Oscar A on Mar 7, 2019
The reviews were great.
chris l on Mar 2, 2019
Imperial yeast is my new favorite
Bill C on Jan 7, 2019
200 billion cells! This brand of yeast is awesome!!
JAMES K on Dec 12, 2018
first time using this yeast
Donnie F on Nov 17, 2018
Trying this year out for my Porter
Scott B on Oct 30, 2018
Very reliable yeast for porters.
Ronald W on Oct 17, 2018
I love all Imperial Organic Yeast. It kicks off super quick and it rips through fermentation.
Alexander S on Sep 14, 2018
Milk stout
Ralph Sprandel on Sep 5, 2018
Dry Irish Stout
Christopher G on Feb 14, 2023
Last strain died
Chris C on Nov 21, 2022
Should I be worried if my yeast pack is swollen?
Mariano Sanchez on Aug 28, 2019

4.7 / 5.0
21 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Rated 5 out of 5
Imperial Darkness
Received the Imperial A10 Darkness on November 21st. The manufacturing date was October 25th. Made a yeast starter for an OG of 1.068. October 28th pitched yeast a 2:30 pm by 7:00 pm started seeing action and a krausen starting in the ferminter.
Next morning fermintation was going great.
December 1, 2022
1 year ago
Rated 5 out of 5
Very Active Fermentation
Currently being used to ferment an imperial stout with a OH of 1.094, did a very fast job fermenting majority of it was done in the first three days, now it’s slowly eating through the remaining sugars.. created a 2L starter with it a day before brew day and it instantly starting working as soon as it was added to the carboy
September 15, 2022
1 year ago
Rated 5 out of 5
Super Viable
Fantastic product. Super viable.
January 3, 2021
over 3 years ago
Rated 5 out of 5
Love the high cell count. Fermentation takes off within about 2 hours of pitching.
May 6, 2020
over 4 years ago
Rated 5 out of 5
Active fermentation started in 2 hours, slowed in 3 days, and an occasional bubble at 3 weeks. Hit final gravity at 3 weeks also. This required a blow off tube for the first 4 days also.
Worst cleared nicely!
March 26, 2020
over 4 years ago
Rated 1 out of 5
No fermintaion at all. Had to repitch with another yeast
March 19, 2020
over 4 years ago
Response from MoreFlavor
Brad - Sorry to hear, this is certainly not typical with Imperial. Please give us a call at 1-800-600-0033 or email us at info@moreflavor.com so that we can assist you. We are here to help. Cheers!
April 29, 2020
Zach R Staff
Rated 5 out of 5
Perfect in Honey Porter
Pitched directly in 5 Gal 1.08 OG Honey Porter, fermentation started within 6 hours, very nice flavor
March 18, 2020
over 4 years ago
Rated 5 out of 5
Awesome little microorganisms!
Great active yeast. Even better flavor.
Very Active in Imperial Stout.  Will need blow off containment.
Very Active in Imperial Stout.  Will need blow off containment.
January 10, 2020
over 4 years ago
Rated 5 out of 5
Great yeast
This strain is awesome
February 15, 2019
over 5 years ago
Rated 5 out of 5
Used a starter. Low fermentation temperature made a very clean and delicious porter.
October 5, 2018
over 6 years ago