Reviving a Stuck Beer Yeast: Tips and Tricks to Get Your Brew Back on Track

beer yeast

Written by Benjamin Parr

My passion for homebrew led me to set up KegThat! I work as a software developer during the day and manage kegthat on evenings and weekends. Occasionally I write some blog posts when I get the time!

2 April 2023

There’s nothing quite as disheartening as discovering that your homebrew has a stuck fermentation. But fear not, fellow brewers, as we’re here to help! In this blog post, we will guide you through the process of reviving a stuck beer yeast, so you can get your brew back on track and enjoy the fruits of your labour. So, let’s dive in and see how we can breathe new life into your fermentation.

Identify the problem

The first step in tackling a stuck fermentation is to identify the root of the problem. There are several potential culprits that could be hindering the yeast’s activity:

  • Inadequate yeast cell count
  • Poor yeast health
  • Insufficient nutrients
  • Unfavourable fermentation conditions (e.g., temperature, pH)

By assessing each of these factors, you can pinpoint the issue and take the necessary steps to resolve it.

Rehydrate your yeast

If your yeast has become dehydrated, it’s time to give it a little TLC. We recommend rehydrating your yeast in a sterilised container using warm water (approximately 30-35°C) and a pinch of sugar. This will help to revive the yeast and encourage it to start fermenting again.

Aerate your wort

Yeast requires oxygen to reproduce and maintain good health. If your wort lacks sufficient oxygen, it can lead to a stuck fermentation. To remedy this, we suggest aerating your wort by vigorously stirring it or using an aquarium pump with a sterile air stone. Be cautious not to over-aerate, as too much oxygen can cause oxidation and adversely affect the flavour of your beer.

Add yeast nutrients:

A lack of essential nutrients can hinder yeast performance and lead to a stuck fermentation. To give your yeast a much-needed boost, consider adding a yeast nutrient to your brew. We recommend using products such as Fermaid-O or Yeastex, which provide the necessary vitamins, minerals, and amino acids for optimal yeast health.

Adjust fermentation temperature:

Temperature plays a crucial role in yeast activity. If your fermentation has stalled due to an unsuitable temperature, it’s time to make some adjustments. Ale yeasts typically perform best at temperatures between 18-22°C, while lager yeasts prefer cooler conditions, around 10-14°C. Keep in mind that fluctuating temperatures can also cause issues, so aim for a stable environment to ensure a healthy fermentation.

Rouse your yeast

Sometimes, all your yeast needs is a little encouragement to get back to work. Gently rousing the yeast by swirling the fermenter can help redistribute it throughout the wort and stimulate fermentation. Be mindful not to introduce oxygen when rousing, as this can lead to oxidation.

Consider repitching

If all else fails and your fermentation remains stubbornly stuck, it may be necessary to repitch a fresh, healthy yeast strain. We recommend opting for a highly attenuative and alcohol-tolerant strain to give your brew the best chance of reaching its desired final gravity.


Reviving a stuck beer yeast can be a bit of a challenge, but with patience and a bit of know-how, you can get your fermentation back on track. By following the steps outlined in this blog post, you can breathe new life into your yeast and ensure a successful brew. Remember, it’s all part of the learning process, and each hiccup along the way only serves to make us better, more knowledgeable brewers. So, don’t be disheartened, and keep brewing!

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