What Happens When We Use Two Yeasts in a Beer?

11–14 minutos

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What happens when we use two yeasts in a beer?

Already beer , we often resort to using different types of malt, different types of hops, but more than one type of yeast is almost never used in the same beer and mixing yeast can bring fantastic and incredible unique complex results when we use more than one type of yeast .

In beer, this can be done with two very different objectives, the first of which is to express the sensory characteristics of the esters formed by yeast during the fermentation of a single yeast, while we can also take advantage of characteristics such as alcohol tolerance and the ability to attenuate other yeasts.

In which this second yeast directly influences the sensorial characteristics of the first and the second form would be a form where we want the opposite wherever the two sensorial characteristics the esters the by-product of the fermentation of both yeast

are expressed that are present in the final beer of this type of use can generate extremely complex results from a sensorial point of view and even more unique that you will not find in any other beer or yeast with similar results.

The problem is that mixing yeast is not as simple as mixing malt and mixing hops, mixing yeast It is much more than a science.

It’s an art, it’s a hobby in itself, it can be extremely complex and extremely rewarding to be able to explore this resource, the problem is that we have to start understanding what the principles of aroma formation are and how to use the yeast .

To understand how we can better explore these living organisms, they need energy to survive and that is why yeast, when metabolizing the sugars in the must, is when it obtains a good amount of energy and is able to have a good energy reserve and will survive. and it begins to produce compounds to give rise to a daughter cell.

The yeast begins to produce pieces of protein that are amino acids. It will begin to reproduce some specific types of fat that make up the cell membrane and are essential for a new daughter cell to perform well in life and during this process of producing amino acids and fats.

Most beer aromas are formed by esters of higher alcohols and sulfur compounds are all obviously and microorganisms are complex, but most of them are associated with cell growth diacetyl has as a by-product higher alcohols diacetyl sulfur compounds and the like.

So most of the formation, the aroma of brewer’s yeast associated with the cell growth phase, thinking to myself, conditions where there is beer, it will be much more esterified and with much more alcohol content, we will see that there is always or almost always

a relationship there with cell growth, for example, a little

A yeast.

If you use a little yeast until it metabolizes all the sugars in the wort, it will go through several stages of reproduction, but the reproduction with more ester and more alcohol is greater.

At higher temperatures, the cell membrane becomes more fluid yeast can remove more sugars from the wort there, the reactions generally happen faster, so it reproduces more reproduces more at high temperature more ester and more alcohol, high OG beer until it metabolizes all the sugar, but it will go through many stages of cellular reproduction ester and higher alcohol.

But if we carry out fermentation under pressure, we will make it difficult for the yeast to reproduce due to a series of factors, it reduces the PH, increases the solubility of CO2, which inhibits some biochemical mechanisms of yeast reproduction, making reproduction difficult, the result is less esters and less higher alcohol.

As macrocervejarias he has this as a natural resource they have a very high tank the pressure at the bottom of the tank is enormous the yeasts have more difficulty reproducing and therefore have cleaner beers unlike the Belgians who want beers but with more ester expression they sometimes have to tilt the fermentation tanks or make very wide open tanks with a low height to have more ester and sometimes even something higher

The meaning of this is precisely associated with one of the forms of yeast mixture what we can do when we want to express the sensory characteristics of a single yeast, but this yeast It could be a yeast that doesn’t attenuate as much, it could be a yeast that has a low alcohol tolerance and then we might want to use those features of another yeast

To make this happen, it’s very simple, we add the first yeast at the beginning of the fermentation phase, just as people do normal addition, this yeast will go through the lag phase and will go through the exponential phase. beer when it starts to fail, either because alcohol tolerance has already been reached or because it has already metabolized or whatever it can metabolize, then you come in with the second yeast  

This second yeast will find a much more hostile environment with few nutrients, with little sugar with the lowest PH saturated with CO2 and will have a lot of difficulty reproducing, of course it will metabolize the rest of the sugars that the other non-metabolized one will have cell reproduction but it is very less expressive

This way you will be able to maintain the almost intact sensorial characteristics of the first yeast and even attenuation and alcohol tolerance, if applicable, of the second yeast. I have used this resource thousands of times in the past when I started making beer I didn’t have so many yeast like today and do a style that I really like.

The problem is that there is no theory of how much yeast in this second dosage I usually use more or less the same as I use in the first dosage. Remembering that it is not so relevant because even if you use less you will not have as much ester production since the medium is not so favorable for yeast growth .

This way of using yeast is quite interesting, it has a series of applications, but the other way of making a Blend is another fantastic way, when we add two or more yeasts at the beginning of the fermentation we will have a mixture of the sensory characteristics of yeasts and they will end up being the only ones that no one else has.

The big problem is that it is very, very difficult for you to predict the outcome. Of course, we can take as a starting point that the final result will be a mixture of the characteristics of yeast that you will use, but this is not linear, if you use half of one half of the other you will not have half the aroma of one half the aroma of the other

and there can be synergistic effects where similar aromas complement each other, decreasing your Thrash Rose aroma, making you smell much more aroma than you would with a single yeast.

The problem is that the growth speed of yeasts is different, so if you inoculate half of one and half of the other, one of them may grow much faster and it will metabolize most of the sugars, it will have more phases of cell reproduction and will have the dominant aroma, the dominant sensory profile, sometimes even overshadowing the other sensory profile

So there is no way to escape the experimentation phase, you take as a basis that your sensory profile will be a mixture of the sensory profile of one and the sensory profile of the other and then you can start with, for example , half to half On your journey to find the perfect blend and sometimes one will stand out

And then you reduce the amount of this in the next generation until you reach what is yours blend perfect beer , some things are more predictable, for example alcoholic tolerance and attenuation, this will always be given by the yeast with greater tolerance or greater attenuation.

There is a phenomenon also called co-flocculation when you have two yeasts they can help each other to flocculate more or less on average but tending towards the flocculation of the more flocculating yeast, if you have a slightly flocculated yeast and a very flocculated one you will have one a finish tending to be more flocculating than a medium finish that a study carried out by Light light they tested two yeasts and their mixture

You can see that in the end, despite decanting the blend faster, the balance is very similar to the average flocculation of the two yeast and one of the biggest problems when we make the mixture, the yeast blend is the issue of reuse, we can’t reuse satisfactorily directly by simply taking the sludge and reproducing the sludge, this is because yeast growth accelerates

are different and as much as the brewer’s yeast They will tend not to compete with each other because they do not see each other as different. It is the same microorganism, the people who selected them and removed a characteristic that they placed there, but among them they are the same. The yeast that reproduces the fastest, even a little faster, will eventually dominate.

Now if your Blend has yeasts that use different carbon sources, for example, you have a diastase yeast that can consume dextrin, then you tend to achieve the balance of proportion, do not suppress one, you will reach ninety percent of one and 10% of the other as balance

and it will stay there forever because the first yeast is the fastest it will consume most of the carbon sources and will not consume it anymore because it has reached what it could do

the second yeast is sometimes slower, it can consume more carbon sources than the other, so there is a balance when you take a mixture of other microorganisms, this is quite common because that one reproduced a mixture of Betta with pediococcus with

saccharomyce does not inhibit and suppress these four components because there are sources of carbon other than nitrogen is another thing, but when we talk about yeast, yeast just without considering anything else the small standard that we use so it is very very easy you inhibit one and you cannot

reuse it and who wants to start exploring blends, which in my opinion could even be a completely new hobby due to the complexity, time and the unique results you can achieve

Turned on have a very interesting fermentation profile, the tropical fruity citrus profile also matches very well with the proposal.

Finally, a suggestion that is quite interesting for other reasons is the mixture of one or more yeasts that turned on as brewer’s yeast they do not have a sexual reproduction phase So when you put two or more yeasts and you will always have the same yeasts reproducing now go to Kveik

It is not for everyone but for a part of the Kveik this is not valid, the Kveik can go through a phase of sexual reproduction by exchanging it’s genetics with another Kveik which is that if it is another Kveik it will give rise but it will be totally new.

The blend will not only generate a unique beer, but it will generate it can become a unique yeast, it is not that simple, the sexual reproduction phase of yeast happens when it enters the spore phase

So you have to go through the phase where the yeast dries, it is in this phase that they reproduce sexually, but then you can have a yeast, now it is not a single Blend and it can be a single

A unique yeast that only you have from this strain. This deserves a whole article talking about how you could isolate it and keep it just for yourself or share it, it doesn’t have to be selfish either but it’s something very interesting to explore I hope you enjoyed it