British Isles

Step into the heart of English brewing with JY028, a classic strain that brings the soul of Burton-upon-Trent to your fermenter. Revered for its crisp, minerally profile and subtle fruit notes, this yeast crafts balanced, dry ales that let malt and hops shine. Perfect for pub-style bitters, robust porters, or hefty barleywines, JY028 delivers tradition with modern reliability. Performs better in mineral-rich water, can ferment sluggish if water is very soft. 

It ferments clean and crisp, with a mineral backbone that evokes Burton’s hard water. Expect restrained fruitiness—hints of apple or stone fruit at warmer temperatures—paired with a dry finish that keeps your beer refreshing yet bold.

Sourced from Burton upon Trent, this Saccharomyces cerevisiae strain produces nice apple/pear notes with hard candy esters. Finishes clean and malty.  Whether you’re brewing a hoppy IPA, a robust porter, or a sessionable bitter, Burton delivers timeless character with every pint. This yeast likes water of a high mineral content, and is better suited for higher gravity ales compared to some other British yeasts. Closely related to JY028, a little less robust with more ester character.

JY309 is a quintessential British ale yeast strain, sourced from a very famous classic cask-ale brewery in the Wirral, UK. This strain produces bright, hop-forward beers with a nod to classic UK pub traditions. JY309 ferments cleanly, accentuating citrusy and floral hop characters with subtle notes of biscuit and light fruit esters, evoking orange zest and grapefruit. Its versatility shines in session bitters, golden ales, and pale ales, delivering a crisp, refreshing finish with just enough malt backbone to balance bold hop profiles. Note that this yeast does best in open-fermenters, and does not like high gravities. Can easily be repitched and skimmed. 

JY311 is a timeless British ale yeast strain originating from one of the Thames breweries.This strain is a favorite for brewers crafting authentic English-style ales due to its robust character and alcohol tolerance. JY311 delivers a harmonious blend of soft fruit esters—think apricot and pear—with a delicate malt sweetness, rounded out by a clean, slightly tart finish. Its versatility makes it perfect for Bitters, ESBs, and Porters, where it enhances malt complexity while allowing subtle hop notes to shine. With moderate attenuation and flocculation, JY311 produces a clear, well-balanced beer that’s both approachable and full of character, evoking the charm of a classic UK pub pint. This strain likes moderate hardness of water, so keep your mineral content in check.

JY316 is a traditional English ale yeast strain, sourced from Newcastle. This strain is a steadfast choice for brewers crafting classic British bitters and session ales, delivering a clean and balanced fermentation that highlights malt and hop character. JY316 produces light fruit esters with hints of pear and subtle floral notes, complemented by a low sulfur profile that ensures a smooth, approachable finish. 

Note that fermentation speed is moderate (7-14 days for 12 Plato wort). The mineral level of the wort needs to be low - soft water - otherwise the strain will struggle.  Low flocculation results in a slightly hazy beer with excellent drinkability. Ideal for Ordinary Bitters, Best Bitters, and Milds. This strain does not do well above 15P. 

JY319 is a lively West Country ale yeast strain. Good for brewers that want vibrant, yeast-driven bitters. This strain brings a bold personality to the brewery with its rapid fermentation and distinctive flavor profile. JY319 produces moderate to strong esters, evoking ripe banana and tropical fruit, alongside a moderate sulfur note that fades with conditioning. It can be slightly phenolic, resulting in a hint of spice. With moderate flocculation, JY319 creates a high initial head and yields a moderately clear beer, balancing haze and clarity for a true West Country aesthetic. 

Needs soft water and is slightly phenolic. Don't go overboard with the gravity. Keep it traditional. 

JY320 is a refined southern English ale yeast strain. Good for classic Best Bitters and Strong Ales, this strain follows a slow fermentation that enhances malt complexity and hop balance. JY320 produces moderate esters, imparting a mild stone fruit character, with a faint herbal note.  Thriving in high-mineral worts, JY320 yields a polished beer with minimal sulfur, while its moderate flocculation creates a light fermentation head and settles into a compact sediment, resulting in a clear, refined pint. 

This heritage strain is a slow fermenter (7-14 days) and needs high-mineral worts to complete fermentation. It can handle higher alcohol levels better than other heritage English strains. 

JY322 is a quintessential North-Yorkshire ale yeast strain. JY322 produces moderate esters and nutty undertones, paired with a restrained sulfur note that dissipates during conditioning, enhancing malt and hop character. Its preference for high-mineral worts accentuates a robust malt backbone, making it ideal for Ordinary Bitters, Best Bitters, and Yorkshire-style Pale Ales. With medium flocculation, JY322 forms a thick, creamy head during fermentation, often requiring rousing or antifoam to manage vigorous krausen, and settles into a moderate sediment for a clear yet flavorful beer. Light phenolic flavors may emerge (the strain is lightly POF+), adding a hint of spice to the finish. 

This is an heritage English strain. It is a very strong krausen producer, and needs high-mineral wort to finish. Lightly phenolic. Does not do well in high gravity worts, stay traditional.

JY323 is a heritage English ale yeast strain. Used for traditional bitters with a focus on malt-driven clarity. JY323 produces low levels of esters, offering subtle hints of biscuit and faint fruit, complemented by minimal sulfur for a crisp, unadulterated finish. Its preference for high-mineral worts enhances malt sweetness and hop balance, making it a perfect fit for Ordinary Bitters, Best Bitters, and English Pale Ales. With high flocculation, JY323 generates a moderate fermentation head and settles quickly into a dense sediment, delivering a brilliantly clear beer that showcases the purity of classic English styles. 

This is a heritage English yeast. High mineral worts are essential, and fermentation can be slow (7-14 days). Keep the temperature above 68F. Keep the gravity appropriate. 

JY324 is a heritage English ale yeast strain. Perfect for brewers aiming to craft classic bitters with a touch of regional character, this strain offers a slow, methodical fermentation that enhances malt and hop synergy. JY324 produces moderate esters, imparting gentle notes of orchard fruit paired with low sulfur for a clean, harmonious finish. Its preference for high-mineral worts amplifies malt richness, making it ideal for Ordinary Bitters, Best Bitters, and Kentish Pale Ales. With low flocculation, JY324 forms a light fermentation head and settles minimally, resulting in a slightly hazy beer that carries a rustic, handcrafted charm. This strain’s deliberate pace and balanced profile reflect the pastoral elegance of Kent’s brewing tradition, delivering ales with depth and sessionable appeal.

Heritage English ale strain. Slow fermentation and high mineral worts are needed for fermentation. Slight haze after fermentation is normal. Keep gravity low, does not like high plato worts. 

JY325 is a bold English ale yeast strain.  Selected for it ability to create richly flavored bitters and milds, this strain delivers a rapid fermentation that produces beers with a distinctive, estery character. This strain produces strong esters, evoking ripe plum, dark cherry, and a hint of toffee, harmonized by a low sulfur profile for a clean, robust finish. Its preference for high-mineral worts enhances malt depth and hop clarity, making it ideal for Ordinary Bitters, Milds, and Best Bitters. With high flocculation, JY325 generates a moderate fermentation head and settles quickly into a dense sediment, yielding a brilliantly clear beer that showcases its vibrant flavors. This strain’s vigorous performance and ester-forward profile capture the hearty, industrious spirit of Lancashire’s brewing legacy, offering ales that are both complex and approachable.

Heritage English ale strain. Flavorful and dropping bright. Keep gravity in check, keep it traditional. Needs high-mineral wort. 

True heritage English strain. Isolated from a 1903 Bass Kings ale bottle by Jasper Yeast. Good fermentation characteristics, lightly POF positive. This is a new isolate, stats are limited. 

JY336 is a heritage English ale yeast strain from a famous brewery in Sheffield. Great for sessionable, cask-conditioned bitters, this strain delivers a clean, malt-forward fermentation that embodies the working-class spirit of South Yorkshire’s steel city. JY336 produces light esters with delicate notes of biscuit and soft apple, harmonized by a crisp, slightly nutty finish that accentuates malt sweetness and moderate hop bitterness. Its preference for high-mineral worts enhances the robust malt character typical of Sheffield’s brewing heritage, making it ideal for Ordinary Bitters, Best Bitters, and English Pale Ales. 

This is a heritage yeast. Keep gravity within reason. 

JY347 is a strong top-cropping ale yeast strain. Good for malt-forward beers, this strain delivers a rich, complex profile with distinct fruit esters interwoven with a robust malty backbone. Ideal for brewers seeking to create high-quality, full-flavored beers, JY347 shines in styles that emphasize malt depth and subtle fruitiness. Its high flocculation ensures excellent clarity without filtration, though careful handling is required to avoid stress-induced diacetyl or sluggish fermentation. 

JY347 is an heritage English yeast. A thorough diacetyl rest is recommended to achieve a clean, polished finish.  This can take multiple days. This strain starts slow, give it extra oxygen to finish out. This is essential. Oxygenate on day two after pitching! Do not let this  strain get too cold during fermentation. Let it free rise when 50% attenuation has passed.