Tips From The Pitch: Winter is Coming, Big Beer Brewing

With winter on its way, now is the perfect time to craft robust beers that stand up to the season from barleywines and imperial stouts to other high-gravity styles. Get a head start on your brewing schedule to ensure these complex beers are perfectly aged and ready to enjoy by winter’s arrival.

Making these big, winter-warming brews successfully means understanding the elevated starting gravities and extended fermentation times demand meticulous attention to yeast management, nutrition, and environmental control. Check out our must-have tips for brewing these high-strength, winter-ready beers.

More Food = More Yeast

• To achieve complete attenuation with high-gravity worts, it is essential to pitch a sufficient quantity of healthy, viable yeast. Just as a bigger Thanksgiving feast requires more guests, a high starting gravity demands a correspondingly robust yeast population to drive fermentation to completion. This helps minimize the risk of sluggish or incomplete fermentations.

Pick A Healthy Generation

• Select a yeast generation that has demonstrated robust vitality and consistent attenuation, ideally from the third to fifth generation.
• Yeast with previous fermentation experience brings enhanced stress tolerance, higher metabolic activity, and predictable results under demanding conditions. 
• Due to particularly harsh fermentations, repitching should not be planned after the brew, so utilizing a good-fermenting higher generation can be ideal for this situation.

Build A Healthy Yeast Cell

Proper nutrition is essential for the marathon fermentation of bigger beer. Weak membranes are less able to withstand the osmotic pressure of high-gravity worts, leading to cell rupture and death. 

Risks of Unhealthy Cells

• Poor Fermentation, such as reduced alcohol tolerance and increased off-flavors
• Poor Nutrient Uptake: Cells with compromised membranes struggle to transport necessary sugars and nutrients, leading to less efficient fermentation.
• Less Budding/Yeast yield for subsequent batches

Oxygenate More 

Yeast depends on oxygen to provide the building blocks needed to synthesize unsaturated fatty acids and sterols, which are essential components of the yeast cell membrane. These unsaturated fatty acids create a more permeable and fluid membrane, allowing cell replication and transportation of vital compounds in and out of the cell.

• With a higher starting gravity, the viscosity of the wort will impact the solubility of oxygen. Be sure to keep this in mind, when adding DO at knockout. A longer contact time or higher rate might help.
• Depending on attenuation rates, a secondary burst of DO may also benefit fermentation at the 12 hour mark. During this time, the first round of budding can happen with the younger cells also benefiting from oxygen uptake. 

Recommended DO Rates: 1ppm per Degree of Plato

Provide Enough Nutrients

FAN, Free Amino Nitrogen can either be a friend or foe. With a bigger grain bill, FAN levels should exceed what is necessary for a good fermentation. From a previous study, we saw faster fermentations with WLP001 California Ale Yeast®, the addition of FANMax Bio® reduced the time to final gravity by around 50% in both 22 and 25 Plato wort.

On the other side of the coin, residual FAN levels can increase risk for contamination and greatly reduce shelf life from staling. Be sure to monitor residual FAN levels and adjust recipes accordingly.

Use Brewing Aids

• Off-flavors such as Acetaldehyde and Diacetyl can be a more common problem with an intense big beer. Pitching brewing aids such as Zinc Buddy™ & Brewzyme-D at the start of fermentation can reduce these off-flavors and help quicken fermentation timelines.
  
   
  • Zinc is a cofactor in the enzyme alcohol dehydrogenase, helping facilitate and speed up the reaction from acetaldehyde to ethanol.

  • Zinc Buddy™ promotes the uptake of maltose and maltotriose, resulting in: Increased attenuation, up to 95% on all-malt beers & beer reaches terminal gravity in 1-2 fewer days, for most ales.

Yeast Options

For high-gravity stouts and porters, strain selection plays a critical role in achieving both expressive character and optimal attenuation. Pick strains to style with high attenuation rates to drive fermentation to completion and minimize residual sugars for cleaner big beers or strains providing esters that complement the malt bill and leave some residual sweetness for a more robust sweetness.

For brewers seeking a balance between robust ester profiles and a lower final gravity, consider blending a highly expressive English strain with a proven high-attenuation yeast. This approach supports both complexity and efficient fermentation kinetics, resulting in a finished beer with desired depth and technical consistency.

Temperature Considerations

• Raise the temperature throughout fermentation, especially in the later half. Raising the temperature helps get the yeast awake and active to help finish fermentation.
• For a more robust, ester forward fermentation, ferment on the slightly higher side
  • Note: A higher temperature can also cause a higher increase in Fusel Alcohols, Acetaldehyde, & Diacetyl

By carefully managing yeast health, nutrition, and environmental factors, brewers can confidently tackle the challenges of high-gravity brewing. These robust, complex beers are more than just a seasonal offering, they are a testament to the brewer's skill and patience, providing rich, warming experiences that are perfectly suited for the colder months ahead. Embrace the season and enjoy the reward of a perfectly crafted winter brew.