Yeast Pitch Rate Effects on the Dunkelweizen Style

The Wyeast 3068 – Weihenstephan Weizen yeast strain is the classic Hefeweizen yeast strain. It is also one of the most popular German wheat beer strains used worldwide. The Weihenstephan Weizen yeast strain is typically used in the production of Hefeweizens, Dunkelweizens, and Roggenbiers. This yeast strain produces a balance of banana esters and clove phenolics. Manipulating the balance towards either ester production or phenolics production can be done with an easy trick. That trick? Change your yeast pitch rate. In this post, we’ll explore how to change the pitch rate and the effects that under- and over-pitching the yeast will have on the finished beer.

Some Quick Background Information On Wyeast 3068

Before we look at the effects of under- and over-pitching, there are a two things to know about this yeast strain. First, the Weihenstephan Weizen yeast strain often produces a sulfur aroma during fermentation. With some conditioning, the sulfur aroma will clear out. Second, this yeast strain will also remain in suspension for an extended period of time following attenuation. For truly clear beer, filtering is required; however, filtering can also reduce the amount of esters and phenolics in the finished beer.

How to Change the Yeast Pitch Rate

According to Wyeast, the typical pitch rate for the Weihenstephan Weizen yeast strain (Wyeast 3068) is 125 ml of yeast slurry and nutrient to a 5 gallon batch of wort. Decreasing that amount will under-pitch, while increasing that amount will result in over-pitching. Depending upon just how much you under- or over-pitch, the effects will range from subtle to drastic. The extreme ends of under- or over-pitching could potentially result in flaws with the finished beer or even worse issues.

The Effects of Under-Pitching and Over-Pitching

Understanding the effects of the yeast pitch rate on the Dunkelweizen style will allow you to tailor the finished beer to your desired tastes.

Under-Pitching
Increasing The Ester Production (Banana)

Decreasing the pitch rate will contribute to increased ester production, yielding more banana notes to the beer. You can achieve additional ester production by increasing the fermentation temperature and increasing the wort density (wort density = specific gravity).

Concerns When Under-Pitching

A low pitch rate can lead to:
– Excess levels of diacetyl
– Increase in higher/fusel alcohol formation
– Increase in ester formation
– Increase in volatile sulfur compounds
– High terminal (finishing) gravities
– Stuck fermentations
– Increase risk of infection

Over-Pitching
Increasing The Phenolics Production (Clove)

Increasing the pitch rate will contribute to increased phenolics production. This can result in a near complete loss of banana character. Decreasing the ester level will allow a higher clove character to be perceived.

Concerns When Over-Pitching

A high pitch rate can lead to:
– Very low ester production
– Very fast fermentations
– Thin or lacking body/mouthfeel
– Autolysis (Yeasty flavors due to lysing of yeast cells)

Dunkelweizen Yeast Pitch Rate Educational Material

Keep the handout readily available for the next time you brew a Dunkelweizen and you are looking to manipulate the esters and phenolics in your Dunkelweizen.