Fermenting Beer with Fermentis SafAle K-97 Yeast

Available in various sizes—11.5 g, 100 g, 500 g, and 10 kg—SafAle K-97 comes with a technical data sheet from Fermentis. This sheet provides detailed specifications. Whether you're brewing at home or for small commercial runs, this yeast offers predictable attenuation and easy handling.

This article will guide you through practical, technical advice and a recipe example for using German ale yeast SafAle K-97. You'll learn about fermentation tips, dosage, and temperature ranges. It's tailored for both hobbyists and small-scale professional brewers, with troubleshooting tips included.

Key Takeaways

• SafAle K-97 is a dry ale yeast optimized for German-style and delicate ales.
• Packaging from 11.5 g to 10 kg supports both homebrewers and small breweries.
• Product is E2U™ with a technical data sheet available from Fermentis.
• K-97 produces subtle floral and fruity esters when used at recommended conditions.
• The article offers practical steps for fermenting beer with K-97 and troubleshooting tips.

Why Choose Fermentis SafAle K-97 Yeast for Your Ales

Brewers select K-97 for its delicate, floral, and balanced fruity notes. It's a German ale strain, known for its subtle ester contributions. This makes it perfect for beers that require finesse, avoiding bold phenols.

K-97 is celebrated for its ability to form a strong, firm head. This characteristic enhances aroma delivery and contributes to a smooth, pillowy mouthfeel. It's a testament to the yeast's role in shaping the beer's texture and flavor.

It's also a reliable choice for recipes with a high hop content. K-97 maintains balance, even in heavily hopped brews. This makes it an excellent option for modern pale ales and session IPAs, where hop flavor is key.

As a German Kölsch yeast, K-97 excels. It also serves as a Belgian Wit yeast alternative for those seeking a cleaner, less spicy profile. Homebrewers often substitute it for US-05 in blonde ales, achieving a crisp finish with a soft, Kölsch-like aftertaste.

Lesaffre's commitment to quality ensures consistent fermentation and predictable outcomes. Homebrewers frequently praise K-97 for its contribution to American Blonde Ale. They appreciate its crisp finish and the soft, rounded aftertaste that echoes traditional Kölsch.

• Delicate floral and fruity esters for subtlety.
• Strong head retention and firm foam.
• Suitable for German Kölsch yeast roles and as a Belgian Wit yeast alternative.
• Consistent results thanks to Lesaffre quality control.

Fermentation Characteristics of SafAle K-97

SafAle K-97 exhibits a clean fermentation profile, with balanced fruity notes. The ester profile K-97 leans towards floral and mild pear or banana esters, within the recommended temperature range. Fermentis indicates medium total esters and medium higher alcohols. This combination provides a subtle fermentation character, without overpowering malt or hop flavors.

Technical metrics are key for recipe planning. Attenuation K-97 typically ranges from 80 to 84%, indicating efficient sugar consumption. This range suggests a relatively dry finish for many ales. It aids in predicting final gravity and body, suitable for both session beers and stronger styles.

Phenolic compounds are not a characteristic of this strain. Fermentis categorizes K-97 as non-phenolic, meaning minimal to no clove or spicy phenolic off-flavors are expected. This trait makes K-97 versatile for British and American ale recipes, aiming for clean ester expression.

Alcohol tolerance and sedimentation are practical considerations for brewers. K-97 is noted to have solid standard ale performance, suitable for typical ale ABV ranges. Sedimentation time is moderate, facilitating a good yeast bed for racking. This helps preserve head retention and clarity with proper conditioning.

Sensory output is influenced by brewing variables. Factors such as fermentation temperature, wort composition, hopping rates, and pitching protocol all impact the final ester profile K-97 and apparent attenuation K-97. By adjusting these variables, brewers can fine-tune the balance between fruity esters, dryness, and mouthfeel.

• Typical ester expression: floral and balanced fruity esters
• Reported metrics: medium total esters and medium higher alcohols
• Apparent attenuation K-97: 80–84%
• Alcohol tolerance: solid for standard ale ranges
• Phenolic off-flavor: absent (non-phenolic)

Recommended Dosage and Temperature Range

Fermentis SafAle K-97 excels when used according to the manufacturer's guidelines. The recommended K-97 dosage is 50 to 80 g/hL for most ales. This dosage ensures consistent fermentation and healthy attenuation.

Adjust the K-97 dosage based on wort gravity and batch size. For higher gravities, use the higher end of the range. Calculate the exact grams needed for your batch size.

The ideal fermentation temperature for K-97 is between 18 and 26°C (64.4–78.8°F). Maintaining this range is critical to avoid off-flavors and ensure timely fermentation. Monitor temperatures closely during the active phase.

Lesaffre’s dry yeast formulation can be pitched directly and used without rehydration. Yet, it's important to follow the recommended K-97 dosage and temperature range to protect the beer's quality and process control.

• Start with a middle-ground K-97 dosage when testing a new recipe.
• Raise pitch rate K-97 for heavier worts or when aiming for faster fermentation.
• Provide adequate oxygen and nutrients for higher gravity worts to complement the chosen K-97 dosage.

Run pilot trials before full-scale production to verify flavor profile and fermentation speed. Small-scale testing confirms that your chosen K-97 dosage and ideal fermentation temperature deliver the expected results for your beer style and process.

How to Pitch Fermentis SafAle K-97 Yeast

Fermentis recommends two effective methods for pitching K-97 yeast. Direct pitch is ideal when your wort is at the final fermentation temperature. It ensures a swift and straightforward transfer. To avoid clumping, evenly sprinkle the sachet across the wort's surface while filling the fermenter.

For those who prefer rehydration, this method involves rehydrating K-97 before adding it to the wort. Use at least 10 times the yeast weight in sterile water or cooled, boiled-and-hopped wort. Hold the liquid at 25–29°C (77–84°F). Sprinkle the yeast into the liquid, then let it rest for 15–30 minutes. Stir gently to create a creamy slurry and pitch it into the fermenter.

Adhering to yeast hydration instructions is essential for maintaining cell health. The resting period allows the yeast to revive gradually. Stirring breaks the surface tension, resulting in a uniform cream that mixes well with the wort.

• Direct pitch dry yeast: sprinkle at target temperature; add while filling to reduce clumps.
• Rehydrate K-97: 10× weight water, 25–29°C, 15–30 minutes, gentle stir, pitch slurry.

Fermentis dry yeasts are known for their robustness, tolerating colder temperatures and skipped rehydration without significant performance loss. This resilience ensures viability and fermentation kinetics in both homebrew and small commercial setups.

Before use, inspect the sachets for any signs of softness, bloating, or damage. Once opened, reseal and store at 4°C (39°F). Use within seven days to preserve potency.

Good aeration or oxygenation of the wort, correct pitch rate, and steady wort temperature are all critical for consistent results. By combining these practices with the chosen pitching method, you can achieve the best fermentation profile from K-97.

Performance in Specific Beer Styles

Fermentis SafAle K-97 excels in lighter, delicate ales. It adds subtle fruity and floral esters, enriching the taste. Brewers often choose K-97 for its clean finish and soft mouthfeel in traditional German Kölsch or session beers.

Homebrewers have found success with K-97 in Belgian-style beers. K-97 witbier introduces gentle spice and a restrained fruit note. This complements coriander and orange peel without dominating them.

An American Blonde Ale trial showcases K-97's versatility. A 6.5 US gallon batch was mashed at 150°F, fermented at 60°F for 10 days, then raised to 68°F for three days. The OG was 1.052, and FG was 1.009. The result was crisp and slightly pillow-y, reminiscent of a Kölsch but with American malt character.

K-97 is ideal for those seeking more European character than strains like Safale US-05 offer. It can replace common American ale yeasts for subtle esters and a softer profile.

K-97 also performs well in hopped beers. It handles higher hopping rates and maintains good head formation and retention. This is beneficial for aroma delivery in pale ales and moderately hopped blondes.

• Try a split-batch test when exploring nontraditional pairings.
• Monitor ester balance and attenuation at small scale before scaling up.
• Adjust fermentation temperature to nudge fruitiness up or down.

Practical Recipe Example Using K-97

This tested K-97 recipe is designed for a 6.5 US gallon post-boil batch. It highlights SafAle K-97’s clean ester profile. Feel free to use it as a starting point for your K-97 blonde ale recipe or make adjustments to suit your taste preferences.

• Fermentables: 8 lb Weyermann Pilsner Malt, 1 lb flaked barley, 1 lb Weyermann CaraHell (13°L).
• Hops: 0.5 oz Cascade (60 min, 6% AA), 2 oz Loral (10 min, 10% AA).
• Yeast: Fermentis SafAle K-97.
• Mash: 150°F (65.5°C) for 75 minutes; mash-out 168°F (75.5°C) for 10 minutes.
• Fermentation: 60°F (15.5°C) for 10 days, raise to 68°F (20°C) for 3 days.
• Gravity targets: OG 1.052, FG 1.009.

Adhere to standard sanitation and rehydration protocols for dry yeast. Ensure proper cell count for a smooth fermentation process.

Expect a short-term haze after kegging, which will clear with cold conditioning. The flaked barley and CaraHell contribute to the beer's body and soft mouthfeel. The Pilsner malt ensures a crisp finish. Loral adds subtle woody and floral notes, complementing K-97’s moderate esters.

To achieve a drier finish, slightly raise the mash temperature or extend fermentation at 68°F. For a fuller mouthfeel, increase the flaked barley by 0.5 lb. Adjust hop timing to enhance Cascade's citrus or Loral's spice in your K-97 blonde ale recipe.

This K-97 brew is ideal for sessionable blondes and hybrid ales. Document mash temperatures, hop timing, and fermentation steps. This will help you refine the recipe for future batches.

Flocculation, Head Retention, and Clarity Considerations

K-97 flocculation exhibits robust, consistent settling. Fermentis technical data highlight effective sedimentation and a dense yeast cake. This characteristic is beneficial for racking and packaging across various ale styles.

K-97 head retention stands out for creating a substantial, firm head during fermentation. This trait is advantageous for beers where foam and lacing are critical, such as German ales and traditional styles.

K-97 clarity generally aligns with medium attenuation, ranging from 80–84%. Beers typically finish dry and clear after standard conditioning. Some batches may appear hazy immediately but clear over time.

• Cold crash or extended conditioning in keg or bright tank to speed clearing.
• Use fining agents like isinglass or gelatin when crystalline clarity is a priority.
• Manage fermentation temperature and oxygenation to influence yeast flocculation German ale and other ale behavior.

Adjuncts such as flaked barley or wheat can enhance body and haze. For glass-clear beer, reduce these ingredients or plan for additional conditioning and filtration.

Practical handling involves gentle settling, transferring off the yeast cake, and allowing time in the bright tank. With these steps, K-97 flocculation, K-97 head retention, and K-97 clarity are well-suited for both homebrew and small commercial operations.

Storage, Shelf Life, and Handling of Dry Yeast

Fermentis SafAle K-97 has a shelf life of 36 months from production. Always check the best-before date on each sachet before use. Proper storage ensures the yeast's viability and flavor performance in brewing.

For short-term storage, temperatures under 24°C (75.2°F) are acceptable for up to six months. For longer storage, keep sachets below 15°C (59°F). Brief exposures up to seven days at higher temperatures are tolerable without significant loss.

After opening, yeast handling becomes critical. Reseal opened packs immediately and store them at 4°C (39°F). Use resealed material within seven days. Discard any soft, swollen, or damaged sachets to prevent contamination.

At packaging, the viable cell count is over 1.0 × 10^10 cfu/g. This high density supports reliable fermentation when storage and handling guidelines are followed. Always check packaging integrity and avoid prolonged storage at warm temperatures.

• Buy quantities that match expected use to minimize extended storage.
• Observe Fermentis shelf life and the printed best-before date on sachets.
• Store unopened sachets in a cool, dry place to maintain dry yeast shelf life.

Good yeast handling begins with careful transport and ends with prompt pitching. Treating K-97 storage as part of recipe planning protects yeast health and brewing outcomes.

Microbiological Purity and Safety Data

Fermentis provides detailed microbiological specifications for SafAle K-97. This allows brewers to evaluate yeast safety before use. The K-97 purity is confirmed to be over 99.9% under Fermentis's microbiological data. It also has a viable yeast concentration exceeding 1.0 × 10^10 cfu/g.

Quality control measures adhere to EBC and ASBC standards. Strict limits are set for common contaminants. These are designed to ensure safe fermentation practices.

• Lactic acid bacteria: less than 1 cfu per 10^7 yeast cells
• Acetic acid bacteria: less than 1 cfu per 10^7 yeast cells
• Pediococcus: less than 1 cfu per 10^7 yeast cells
• Total bacteria: less than 5 cfu per 10^7 yeast cells
• Wild yeast: less than 1 cfu per 10^7 yeast cells (EBC Analytica 4.2.6 / ASBC Microbiological Control-5D)

Pathogenic micro-organisms are strictly controlled to meet regulatory standards. The product is made using Lesaffre’s production scheme. This is aimed at achieving high microbiological purity and consistent yeast safety data.

Ingredient labeling includes Saccharomyces cerevisiae and emulsifier E491 (sorbitan tristearate). Brewers with allergen concerns should examine this information when planning recipes and packaging.

For cellar checks, routine plating and microscopy are recommended. These methods are guided by Fermentis's microbiological data. Regular monitoring ensures K-97 purity across production batches. It supports reliable beer quality.

Scaling Up: From Homebrew to Commercial Batches

Transitioning from a five-gallon batch to hectoliters demands meticulous planning. The recommended yeast dosage is 50–80 g/hL. This ensures brewers can scale up K-97 without compromising on attenuation and ester profile.

Packaging options cater to various operations. Fermentis provides 11.5 g, 100 g, 500 g, and 10kg K-97 packaging. These sizes are ideal for home brewers, brewpubs, and commercial producers. Select the appropriate pack size based on production volume and storage capacity to streamline inventory management.

For commercial K-97 pitching, scale the pitch rate in proportion to wort gravity and volume. Higher gravity beers require more viable cells. Conduct pilot trials at intermediate volumes to validate fermentation performance, attenuation, and flocculation before scaling up to full production.

Process controls are essential for consistent results. Adhere to oxygenation protocols, maintain temperature between 18–26°C, and uphold strict sanitation standards. Regularly monitor gravity, pH, and fermentation activity to detect any deviations promptly.

• Plan yeast mass: calculate grams from 50–80 g/hL and round up for safety.
• Validate in pilot fermenters to confirm expected ester profile and attenuation.
• Use batch records and consistent OG/FG targets to standardize outcomes.

Proper storage is vital for yeast viability. Store dry yeast below 15°C when feasible and rotate stock by best-before date. For large-scale operations, K-97 10kg packaging reduces handling but necessitates robust cold storage and inventory management.

Effective industrial yeast handling practices minimize contamination risk and preserve activity. Employ clean transfer lines, single-use scoops or sanitized tools, and protect yeast from prolonged heat exposure during rehydration or transfer.

Pilot runs are critical for understanding scale effects on ester formation and flocculation. Adjust pitch rate, oxygenation, or fermentation temperature based on these trials. Consistent monitoring and small adjustments ensure reliable K-97 performance across batches.

Troubleshooting Common Fermentation Issues with K-97

Slow or stuck fermentation with K-97 can be alarming but usually has straightforward solutions. First, examine the pitch rate, dissolved oxygen levels at pitching, and the wort temperature. Fermentis advises fermenting at 18–26°C for SafAle K-97. Temperatures outside this range can slow down fermentation.

Next, assess yeast viability. A damaged or improperly stored yeast sachet can lower colony-forming units. If viability is low, try gentle agitation to resuspend the yeast. Ensure the fermentation temperature is correct and add a small yeast nutrient. If gravity remains stagnant for several days, consider repitching with an active starter or fresh yeast.

Identifying off-flavors in K-97 brews is the first step to addressing them. Excessive higher alcohols often result from high fermentation temperatures or underpitching. Maintain the fermentation temperature within the recommended range and ensure the correct pitch rate to prevent hot fusels. If unwanted phenolics appear, remember K-97 is non-phenolic, according to Fermentis. Phenolic notes usually indicate contamination, so review sanitation and check equipment for microbial sources.

Excessive haze or poor flocculation can be a challenge for brewers aiming for clear beer with K-97. Ingredients like flaked barley, high protein malts, or specific mash techniques can contribute to haze. Cold conditioning, finings, or a brief cold crash can help improve clarity. For larger batches, enzymes such as silica gel or isinglass can be effective.

Poor head retention with K-97 often stems from recipe choices, not yeast faults. K-97 typically produces a firm head under normal conditions. Low protein or dextrin grists can reduce foam. Adding specialty malts, wheat, or oats can enhance head stability and mouthfeel.

If persistent issues arise, validate yeast viability through laboratory analysis and review storage history for temperature excursions. Keeping records of pitching rates, oxygenation levels, and fermentation curves aids in troubleshooting. Accurate data makes K-97 troubleshooting more efficient and precise.

Buying and Sourcing Fermentis SafAle K-97 Yeast

Fermentis SafAle K-97 is widely available from homebrew retailers, online stores, and distributors across the United States. Product pages often include technical datasheets and lot information. This helps verify the strain and viability before purchase.

Authorized sellers like MoreBeer, Northern Brewer, and major brewing supply catalogs offer Fermentis K-97 for sale. These retailers provide customer ratings and K-97 reviews. These reflect real brewing outcomes in styles such as blonde ale and Kölsch.

• Purchase from reputable vendors to ensure correct cold storage and valid best-before dates.
• Check packaging size options so you do not store large amounts above recommended temperatures.
• Download the TDS and confirm lot numbers when buying bulk weights like 500 g or 10 kg; arrange cold-chain shipping for larger orders.

Retailer pages often display user feedback. A typical product listing may include several dozen K-97 reviews. These report on attenuation, flocculation, and flavor profile in real batches. Use these notes when selecting strain and pitch rates.

• Compare vendor policies for satisfaction guarantees and shipping thresholds before committing to a purchase.
• Prefer sellers that post clear best-before dates and handling recommendations on the product page.
• If you operate a brewery, work with commercial distributors and yeast suppliers that can provide lot tracking and cold storage documentation.

When you buy K-97 yeast, keep it in cool storage and plan usage to avoid long-term shelf exposure. Smaller packs suit homebrewers, while licensed yeast suppliers can support larger operations with proper storage and logistics.

Conclusion

Fermentis SafAle K-97 is a high-viability dry Saccharomyces cerevisiae strain. It offers subtle floral and fruity esters with medium attenuation (80–84%). Its strong head formation and balanced ester profile are ideal for Kölsch, Witbier, session ales, and Blonde Ale variations. This makes K-97 a favorite among brewers for clean, drinkable ales with a touch of complexity.

To achieve reliable results, follow the brew recommendations for K-97. Use a dose of 50–80 g/hL, ferment between 18–26°C (64.4–78.8°F), and employ direct pitch or rehydration methods as Fermentis suggests. Proper storage and handling during transfer are essential to maintain viability and predictability in fermentations.

Start with small trial fermentations to fine-tune flavor and kinetics before scaling up. Refer to the Fermentis technical data sheet for detailed parameters and guidance. Remember, the product's microbiological purity and shelf life are critical: viable count >1.0×10^10 cfu/g, purity >99.9%, and a 36-month shelf life. Always purchase from reputable vendors to ensure product integrity and consistent performance.

Further Reading

If you enjoyed this post, you may also like these suggestions:

• Fermenting Beer with Fermentis SafAle WB-06 Yeast
• Fermenting Beer with Fermentis SafAle US-05 Yeast
• Fermenting Beer with Fermentis SafAle S-33 Yeast