Yeast – all you need to know


Yeast is an essential ingredient for many baked products, like bread or pizza for example. It’s also used when brewing beer or winemaking. But not all of us know that yeast can also be beneficial for our health. This culinary supplement is very rich in B vitamins, which means it can positively affect our nervous system function as well as the condition of hair, skin and nails. There are different types of yeast you can eat that will enrich your diet. Here’s all you need to know about this interesting type of fungi.

In this article you will learn:

  • Basic information and history of yeats
  • Yeast – the fermentation process
  • Health benefits and how much yeast you can actually eat
  • Types & substitues
  • Using yeast in the beauty products

=> You may also like: Additives Most Likely To Cause Adverse Reactions. Food Additive Numbers List & Effects

What is yeast?

Yeast is a type of unicellular fungi that live on substrates that contain simple sugars. They usually conduct alcoholic fermentation under anaerobic conditions, for example converting carbohydrates into ethanol and carbon dioxide.
You can find yeast anywhere. When you observe the natural environment, you can find yeast spores in the air, flowers, plants, soil, fruits and even in your skin.

When fruit begins to rot, it does so because of yeast. When combined with bacteria, yeast breaks down the fruit’s particles and creates fermentation.

Today, you can find around 30 different types of yeast with many varieties. The most popular type of yeast, and the one most commonly found in shops, is Saccharomyces cerevisiae, also known as baker’s yeast.

History of yeast

According to Wikipedia, the word “yeast” comes from the Old English gist, gyst, and the Indo-European root yes-, meaning “boil”, “foam”, or “bubble”.

People have been using the properties of yeast for centuries, many times not even knowing its nature. Wild yeast is commonly found all over the natural environment. What’s interesting is that lumps of pure yeast were found in one of the pyramids in Egypt. Archaeologists also found early grinding stones and baking chambers for yeast-raised bread, as well as 4,000 year old drawings of bakeries and breweries. This proves that yeast has been recognised as a valuable ingredient for baking, brewing or winemaking for millenia.

You can find yeast in products that contain simple sugars, like fruit for example. In the right conditions, preferably without oxygen, yeast conducts alcoholic fermentation. This is why it has been used in the production of beer and wine since medieval times. Back then, however, no one could explain what was causing the fermentation.

With time, people started using yeast to bake bread. Somehow – possibly by accident – people found out that it was yeast that made a loaf of bread rise. They would harvest the yeast from the foam created during fermentation, rinse it with clean water, seal it in barrels, and store it in ice-houses or wells.

The first person to discover the nature of yeast was the Dutch scientist Anton Philips van Leeuwenhoek, around 1680.

Yeast was used in bakery production in 1781 in the Netherlands. Bakers mixed the brewer’s yeast with potato flour, dehydrated it, and then added it to bread.

Yeast was only identified as a living organism in 1837 by Charles Cagniard-Latour from France and Theodor Schwann from Germany. The two scientists each published this hypothesis independently of each other.

Still, the true nature of alcoholic fermentation and the role that yeast played was first discovered by Louis Pasteur, who was the first to recognise that yeasts were living organisms. Until then, brewers had relied only on wild yeast strains to ferment.

The yeast genome (DNA) was described in 1996 as the first amongst single-celled organisms – it took ten years and required the collaboration of nearly a hundred research teams.

Yeast – the fermentation process

For the fermentation process to be possible without any problems, yeast needs a few special elements and conditions. Without them, fermentation might not happen or could be less successful.

Simple sugars

For the fermentation process to start, yeast needs simple sugars, which allow it to produce alcohol and carbon dioxide. This is the chemical reaction that is typically used by the food industry. Yeast also produces flavouring substances that affect the smell of food products.

To fully understand the fermentation process, let’s use beer production as an example. When malt is being mashed, the enzymes break the starch into simple sugars – glucose and maltose – and the smaller complex sugar, maltodextrin.

Many brewers know that adding raw malt extract makes beer taste sweeter than after adding glucose. This is because glucose is a simple sugar, which becomes fully fermented by the yeast and therefore doesn’t remain in the finished beer. Malt, on the other hand, contains not only simple sugars but also maltodextrin, a complex sugar, which remains in the finished beer and makes it taste sweeter.


These can be provided with the help of nutrients. Generally speaking, yeast needs vitamins, trace elements, and amino acids for fermentation.


Yeast can work without oxygen, but it needs it to multiply properly. The amount of oxygen exposure also has a direct influence on the taste of the finished product. The less oxygen, the more esters will be produced during fermentation.

The right temperature

Temperature is also important for yeasts. As you probably know, all yeast has a temperature range where they function best. It’s important to remember, however, that temperature fluctuations have a very negative effect on the performance of yeast. So even if you’re reaching the limit of the temperature range, it’s worth staying on the same course until the end of fermentation instead of fluctuating.

baker’s yeast

Is yeast good for health?

The health properties of this popular microorganism can be surprising. What are the most important ingredients of yeast?

B Vitamins

Yeast is known for its high content of B vitamins, especially riboflavin and folic acid. B vitamins are primarily responsible for the proper functioning of the nervous system. They can also relieve nervous tension, have a positive effect on the mood, and improve intellectual performance. B vitamins also play a very important role in metabolic processes, including the absorption of carbohydrates – in the conversion of glucose into energy, which is delivered, among others, to the brain.

Vitamin B2 influences the process of creating antibodies, therefore strengthening immunity and B19 is especially recommended for pregnant women. B12, in turn, regulates metabolic processes in the body.

Biotin (Vitamin B7 or Vitamin H) participates in the synthesis of fatty acids, leucine metabolism and plays an important role in the process of gluconeogenesis. Biotin is also an important component of the diet of diabetics. High fasting doses of biotin in patients with type II diabetes mellitus resistant to treatment with sulfonylurea have been shown to reduce glucose levels. Biotin also affects the proper growth and development of the body, as well as the proper condition of the skin.


Yeast contains many essential minerals and is rich in numerous nutrients.

  • Potassium – This regulates blood pressure and controls muscular function. Potassium enables the generation of electrical impulses in our body cells, including the heart muscle cells, which makes it responsible for every beat of our heart.
  • Calcium – In the right concentration, calcium ensures strong bones, healthy teeth, and proper blood clotting. The right concentration of this element also means having working muscles, relaxed nerves, healthy sleep, and a cheerful mood.
  • Magnesium – This stabilises the function of the nervous system and improves the work of grey cells. Magnesium also takes part in the transformation of proteins, fats and carbohydrates. It’s also great for memory and is responsible for the smooth functioning of the cardiovascular system.
  • Iron – This is a component of hemoglobin that transports oxygen. Iron is also essential for the proper growth and development and regeneration of tissues. It stimulates immunity, supports the fight against free radicals and reduces fatigue. Learn more about iron in your diet.
  • Manganese – This plays a role in the production of thyroxine, i.e. inactive thyroid hormones. Manganese is also an element that is the body’s defence against free radicals and facilitates the absorption and storage of iron. Moreover, it has a great influence on the level of libido and fertility.
  • Zinc – This participates in the transformation of proteins, fats and carbohydrates. Zinc also strengthens immunity and is a great defence against colds, flu and other diseases.
  • Phosphorus – This is necessary for the proper functioning of the body, especially healthy and strong bones and teeth.
  • Chromium – Not only helpful in weight loss but also helps to lower LDL cholesterol and increase HDL cholesterol in the blood. Thanks to its properties, chromium stimulates the synthesis of fatty acids and transports amino acids to the cells.
  • Selenium – This mineral lowers the risk of heart diseases, improves blood circulation, and has strong antioxidant properties.


Yeast is also a source of antioxidants, which remove excess free radicals from the human body. Antioxidants slow down the aging processes of the body and prevent the development of diseases known as civilisation.


This reduces cholesterol absorption, thus preventing cardiovascular disease, and also lowers blood glucose levels. The beneficial properties of fibre are mainly emphasised in its ability to improve the digestive tract. Fibre also gives a feeling of fullness for a long time, which makes it an essential ingredient for a slimming diet. If you want to know more about fibre check our article – Fibre in Your Diet.

A serving of 100 fresh yeast provides about 90 kcal, and about 11 g of protein, 2 g of fat, 14.5 g of carbohydrates and 7.4 g of fibre. That said, fresh yeast is not intended for direct consumption, and as we only use a small amount of it for baking, it’s not a significant source of nutrients, especially vitamins.

You can also find dried active yeast, which is characterised by its considerable durability. But while it is a more convenient option, dried active yeast has a slightly different flavour and isn’t a source of valuable ingredients.

A more and more popular option is nutritional yeast, available in the form of powders and flakes. With a nutty mushroom taste, nutritional yeast is a valuable flavour addition to dishes, especially in meat-free and vegan cuisine, adding missing vitamins.

Types of yeast

There are many species of yeast, of which about thirty are well known. Most often, however, yeast is divided into groups according to the method of application. Here are the most popular types of yeast:

Yeast for baking (baker’s yeast)

After sourdough, this is the oldest leavening agent used for baking. You can find several varieties of yeast for baking, specific for consistency, degree of difficulty, or type of application.

  • Fresh yeast for baking. The basic option. This type of yeast comes in the form of cubes, usually in packets of 40-200 grams. It needs to be kept in the fridge and brought to room temperature before using. Fresh yeast for baking is mostly used in an activated form, created by mixing it with warm milk/water and a little sugar. This type of yeast is perfect for all baked goods, like bread, rolls, or cakes.
  • Instant yeast for baking. This comes in the form of tiny granules and is gaining more and more popularity thanks to its ease of use. When using instant yeast for baking you don’t need to apply the solution, which is a great help and saves time. Just simply mix it with flour and other dry ingredients, add warm water or milk, and it’s ready.
    Instant yeast has almost the same effects as fresh yeast, as long as it’s used in the correct ratio: 7 grams to 25 grams (instant yeast vs fresh yeast, respectively). So, if a recipe contains 50 grams of fresh yeast, you must use two 7 gram instant packs.
  • Dry yeasts for baking. This type of yeast is a bit less popular and also comes in the form of granules. Unlike instant yeast for baking, however, dry yeast requires some preparation before use. It needs to be mixed with a little flour and warm liquid at a temperature of 35-40 degrees, but it doesn’t need to be refrigerated or each room temperature.

Nutritional yeast

This more and more popular variety of yeast is a great source of minerals and vitamins. It most often comes in the form of tiny flakes that resemble breadcrumbs. Also known as inactive yeast, nutritional yeast is known for its umami flavour and is highly appreciated by people who follow a vegan or vegetarian diet. The deep cheese-nut flavour makes it a perfect replacement for cheese or Parmesan on a sandwich, in a salad, casserole or a dish with pasta or porridge.

Nutritional yeast is primarily a treasure trove of B vitamins that have a beneficial effect on the nervous system, improve mood and concentration, improve metabolism, increase immunity, and strengthen hair, skin and nails. Manufacturers often enrich nutritional yeast products with vitamin B12, a deficit, especially in a vegan diet, and very necessary for our body (it increases stress resistance, prevents anemia, improves appetite and even reduces the risk of Alzheimer’s disease). Nutritional yeast also contains many valuable exogenous amino acids, which the human body does not produce, so they must be supplied with food.

It does not contain lactose, which can sometimes cause unpleasant ailments in adults, e.g. bloating, abdominal pain and diarrhea. Nutritional yeast may contain gluten, however, because sometimes barley malt or wheat flour is added. Therefore, it is worth looking at the label before buying.

Brewer’s yeast

Few people realise that brewer’s yeast is a component of many herbal calming tablets. If you need to reduce stress levels, then maybe you should look for brewer’s yeast tablets. These can help bring calm in times of strong stress, make it easier to fall asleep, and soothe the nerves. Taking brewer’s yeast tablets can also help strengthen the body’s immunity.

Brewer’s yeast, as the tablets are also called, can also be used as a drink. The yeast drink can be prepared at home and is a great way to cleanse the body of toxins. Prepare the drink by pouring boiling water or hot milk over the crushed yeast. Proper fluid temperature is important here, as raw yeast can cause gas (read also: Top Foods That Cause Gas And How To Stop Farting).

Brewer's yeast

Wine yeast

The function of wine yeast is to convert the sugar contained in wine into alcohol. Since they have an important role to play in this process, they should be properly selected so that the final effect meets the requirements.

Distiller’s yeast

This is an efficient and fast-working strain that allows for creating stronger alcoholic beverages. Distillery yeast is perfect for high quality, high power and guaranteed proper fermentation process. The advantage of distillery yeast is the short fermentation time of the adjusters, which are then destined for distillation.

Kefir yeast

Accompanied by some bacteria, this type of yeast can produce valuable ingredients that can be used during the production of kefir, for example grains and mushrooms. They are also produced with the help of yeast.

Wild yeast

This is most often considered harmful and defective in food products, although it is added to certain types of beer during production.

How do you recognise fresh yeast?

Choosing fresh yeast is extremely important, as adding the wrong dough leavening agent could end up spoiling the entire recipe. You can recognise the freshness of yeast by its creamy colour and slightly sour taste. Fresh yeast can also be easily crushed. If the yeast is greyish-yellow, greasy, or dry, it should not be used. Fresh yeast cannot be frozen. This won’t extend its shelf life, and it will kill all of its properties. It also cannot be brewed.

How much yeast can we eat?

Using yeast in moderation is not harmful. In higher doses, however, yeast can cause allergic reactions, gas, and a feeling of fullness. Migraines, skin irritations, and redness are also possible. It’s also not recommended to consume raw yeast, as it can cause negative gastrointestinal symptoms. People suffering from candidiasis, fungal infections, and allergies to yeast or mould should not use yeast treatment. In the case of inflammatory bowel diseases, it is also not recommended.

The safest way to take yeast orally as a dietary supplement is to use yeast tablets, or to add inactive yeast to the food.

Prepare drinking yeast by pouring boiling water or milk over a small amount and waiting 10-15 minutes. If the yeast is not “killed” before drinking, it will start to ferment in the digestive tract. Instead of providing valuable nutrients, it will just take them from the body, therefore doing more harm than good.

Consuming yeast can cause unwanted effects such as bloating and gas, as well as migraine headaches and allergy symptoms such as problems with breathing, tightness in the windpipe and chest pain.

Yeast should not be consumed while taking certain medications, including anti-depressant inhibitors, meperidine for pain relief, and drugs used to treat diabetes.

Taking yeast is contraindicated in inflammatory bowel diseases, such as Crohn’s disease or ulcerative enteritis, as well as similar problems resulting from autoimmune diseases. Other contraindications include recurrent fungal infections caused by Candida albicans and a weakened immune system, e.g. as a result of the use of immunosuppressants. However, due to the very high content of purine compounds, yeast should not be consumed by people suffering from gout (Do you have gout? Check: All You Need To Know About Gout) or arthritis.

yellow yeast

Yeast – substitutes

If you can’t eat yeast because of digestive troubles, or you simply have no yeast at home, you can replace it with some other substitutes.

Yeast is used to loosen dough. When yeast multiplies in dough it produces a lot of carbon dioxide, making our cakes and bread fluffy. But like all fungi, yeast not only has a cell membrane but also a cell wall made of cellulose. This is what can make yeast cause digestive problems. People with certain sensitivities, for example liver diseases, should exclude yeast from their diet.

One of the best methods of loosening dough without yeast is to use baking soda. Baking powder is an improved way of using baking soda in combination with acidic stabilisers for a chemical reaction.

Baking soda reacts violently with weak acids. As a result of the reaction, carbon dioxide bubbles form in the dough, which lifts the dough. This reaction happens quickly, however, so acids are added at the end of the dough mixing to trigger reactions before quickly putting into the oven. Baking soda is most often associated with sour buttermilk (milk residues from butter production), kefir, or milk acidified with lemon juice or vinegar.

Baking powder is nothing more than just baking soda with acid additives that release slowly at higher temperatures to stabilise the process.

Yeast as a beauty product

Additionally to its nutritional value, yeast can also be used as an excellent cosmetic, helping to improve the condition of hair, nails and skin. This is why it is used as an ingredient by producers of skincare products, especially those for people with acne skin conditions.

Yeast has detoxifying and cleansing properties, which make it a great ingredient for cosmetics especially for seborrheic skin. But yeast appears in many different cosmetic treatments for all skin types.

Yeast does not cause allergies and soothes irritations when used as an ingredient of cosmetic products. It can therefore be used on sensitive skin.

Yeast based cosmetics are not hard to make and can easily be prepared at home. There are many variations of face or hair masks that can be made at home. A basic recipe takes crushed yeast for baking with milk or water, crushed into the consistency of thick cream. This is applied to the skin for 10-20 minutes, until dry, then washed off with warm water. The treatment will cleanse the pores, have a slightly drying effect, normalise the work of the glands, alleviate inflammation and smooth the skin, which will become velvety to the touch. The effects are visible immediately.

Depending on your complexion, you can enrich this basic yeast mask to suit your skin’s unique needs. Adding lemon juice to the yeast mask will slightly lighten the skin. The water can be replaced with olive oil to enhance hydration. Adding grated carrots along with the oil and yeast will nourish the skin.

Before starting to use homemade skincare products, however, it is recommended to contact a dermatologist and check that you have no allergic reactions to any of the ingredients.

Which type of yeast is the healthiest?

The answer to this question is easy. If you care about the nutritional value of yeast, then you should try nutritional yeast.
Why is it a great choice? First of all, it has a nice nutty flavour that can add another level to your meals. It is a great non-animal source of Vitamin B12, which is why it’s used by many vegans and vegetarians. As stated before, nutritional yeast is also high in many nutrients like Vitamin B, fibre, protein, zinc and iron.
The great thing about nutritional yeast is that it can be used as a spice and sprinkled over almost any meal. It tastes great with pasta, soups, sauces, or smoothies.


Despite some cases, in which consuming yeast is not recommended, it can’t be denied that yeast contains many valuable ingredients and nutrients. So if your body responds well to yeast, there are no contraindications to using it.

You should remember, however, that many packaged products are enriched not with yeast, but with yeast-based additives. This is why it’s important to check the labels of products you buy in supermarkets. Yeast-based additives can be listed on ingredients lists as hydrolysed plant protein, yeast extract, or plant protein. The source of natural yeast proteins is fermented products like vinegar, soy sauce, cheese and alcoholic beverages – especially beer and wine. Of course, you can also find yeast in baked goods – the best ones will certainly be home-made.

Yeast can also be valued as a remedy for skin conditions, however, before you begin to treat your skin with it you should first consult a dermatologist or allergist.

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  1. 5 stars
    Thinking about yeast makes me cringe. So, this puts yeast on a different light for me. I never even knew that you could use it on beauty products. Great stuff!

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