The story behind osmotic shock in microorganisms
Until recently, the term ‘osmotic shock’ was just a technical concept in microbiology that seemed destined for laboratories and scientists. However, in the world of the elaboration of fermented drinks, this word took prominence when I discovered that it can be a decisive factor in the success or failure of my most ambitious projects, such as Meads and beers with high sugar content.
What exactly is osmotic shock and how does yeast affect?
Imagine that you are at a party where music rises suddenly and everyone has to cool quickly. That happens to yeast cells when they face sudden changes in their environment. The osmotic shock is that sense of shock that occurs when the surrounding conditions change dramatically in concentration, specifically the amount of sugar surrounding the cell. In these circumstances, the water moves quickly, causing the cell to breathe or expand rapidly, and in extreme cases, it can explode or die from pressure (a form of apoptosis). The most visible consequence: a remarkable reduction in the amount of viable yeast to ferment, which can translate into poor performance.
When should you worry about this phenomenon?
This problem is particularly relevant in the development of products with high sugar concentrations. IPSO Facto, beers such as Barley Wines or extremely mature Stouts, high alcohol wines, very concentrated Meads, intense cider and the popular seftzers with fruit flavors. The reason: all these concoctions are fermented in sweet solutions that, once the fermentation is finished, are diluted to obtain the desired intensity, but in the meantime, the yeast can be subjected to a significant tension due to the difference in the sugar concentrations.
How to dodge the blow and keep your yeast happy?
The key to preventing yeasts being scared and dying in the process is in patience and in a gradual introduction. First, if you use dry yeast, adequate previous hydration helps prepare cells to resist changes. Then, instead of releasing all the yeast in the must or the wort sudden, it is recommended to make a acclimatization process, adding small quantities and mixing gently in several stages before the final fermentation. Thus, cell membranes have the opportunity to slowly adjust to the new reality, avoiding excessive stress.
Step by step method to prevent osmotic shock
First, moisturizes your dry yeast in water at a controlled temperature. Then, prepare a small volume of wort or must with high density and mix it in your yeast starter in short time increases, letting rest between each addition so that the cells can adapt. When the volume of the mixture already contains a significant proportion of the must, it is time to make the final transfer to the fermenter. This strategy, in which the concentration of sugar is progressively increased, helps yeast to maintain their internal balance and reduce mortality.
What impact can the osmotic shock have on your production?
The effect can be devastating if it is not handled carefully. Imagine losing a large part of your yeast due to a simple technical error: your fermentation can be delayed or ended with a lower quality than expected. In addition, the death of cells not only means less fermentative activity, but also the possible formation of unwanted flavors or the appearance of defects. In the world of high -gravity drinks, understanding and controlling this phenomenon is as important as controlling the temperature or oxygen level.
The future of high concentrations in fermentation
As homemade and artisanal producers venture into increasing challenges with concentrated ingredients, understand the internal mechanisms of yeast cells becomes a competitive advantage. New more resistant technologies and strains are under development to face these challenges, but intelligence and patience in practice remain the best weapons to avoid osmotic shock. The research continues, and with it, the possibility of creating more daring, tasty and consistent quality drinks, without productivity being compromised by simple introduction errors.
