Q & A

Read on for answers to some of the questions we are asked most frequently


  • Where did yeast come from originally?

    Yeast has been used for thousands of years – the Ancient Egyptians and Babylonians made leavened bread using wild yeasts. But nobody knew why yeast made bread rise until the 19th century, when the French chemist and microbiologist Louis Pasteur discovered that yeast was a living microorganism and caused alcoholic fermentation.
    The yeast that bakers around the world now use is a strain of Saccharomyces cerevisiae.

  • How long have people used yeast?

    Yeast has been called our oldest domesticated microorganism. Hieroglyphs show that Egyptians used yeast and fermentation to make alcoholic drinks and sourdough bread more than 5,000 years ago. The modern yeast industry, which emerged in the mid-20th century, works on selecting specific strains of yeast and making them available in bulk for various uses.


  • Where can I find yeast in nature?

    Yeasts can be found more or less anywhere there is a source of carbohydrate (sugar). They are found widely in nature, especially on plants and fruits and in the soil.

  • What products contain yeast?

    Yeast is used in a variety of staple foods, including bread, buns, pastries, beer, wine and spirits. It is also used medicinally and in probiotic products and dietary supplements.

  • How much yeast does a typical person consume during a day?

    This depends on the country and culture, but an adult in the EU will consume 2-10 grams of yeast per day.

  • How does yeast affect the flavour of food and drink?

    Yeast brings out the characteristic flavours and aromas of various foods through fermentation.

    • Baker’s yeast adds to the flavour of bread, buns and pastries because the fermentation process naturally releases aromatic compounds such as esters. The longer the dough is left to rise, the more flavours develop.
    • Different types of brewer’s yeast produce different types of beer.
    • When yeast’s role in winemaking was discovered, winemakers selected the most suitable types of yeast to bring out the aroma and character of different grape varieties. Today, yeast is a key winemaking ingredient because it helps ensure consistency of flavour and aroma between vintages.
    • Yeast can also be used to enhance flavours in other food products.

Nutritional value and contents

  • What are beta-glucans and are they to be found in yeast?

    Beta-glucans are a type of carbohydrate (chains of glucose molecules) known to stimulate the immune defence and help lower cholesterol. Yeast stores large quantities of beta-glucans in its cell walls – up to 20% of the dry matter. Beta-glucans are found in bread, but the concentrations are so low that the health benefits are negligible.

  • Does your yeast contain palm oil?

    All yeast made by Jästbolaget is completely free from palm oil.

  • What is a probiotic?

    Probiotics are defined by the FAO/WHO as “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host”. The word probiotic comes from the Greek words pro (for) and bios (life) and is the opposite of antibiotic.

  • Is yeast a probiotic?

    Only one probiotic yeast has been documented so far: Saccharomyces cerevisiae boulardii, which was discovered in 1923 by French scientist Henri Boulard and is used to treat diarrhoea in almost 100 countries.
    Because yeast is inactivated at the end of the bread-making process, it cannot then have a probiotic effect.

  • Does your yeast contain traces of allergens?

    Ordinary baker’s yeast, Saccharomyces cerevisiae, is very readily digested. Yeast is not on the list of products that must be included on food labels under EU Regulation No. 1169/2011 as causing allergies or intolerances. Thanks to Jästbolaget’s effective HACCP food safety programme, we can guarantee that our yeast is free from allergens.

  • Is your yeast GMO-free?

    All yeast produced by Jästbolaget is completely GMO-free.

  • Is your yeast eco-friendly?

    Jästbolaget’s yeast is manufactured in an environmentally friendly way. The main raw material, molasses, is a natural by-product from sugar production. Our boiler runs on biofuel (96% renewable) and all our electricity comes from renewable sources (wind and hydro). Two-thirds of all the energy we use is then recovered using a large 5 MW heat pump and transferred to the municipal district-heating network – a total of 28,000 MWh/year, which is enough to heat 1,500 homes.

  • Is your yeast suitable for a kosher diet?

    Yes, all of Jästbolaget’s products are kosher-certified, except KronJäst Surdeg Fullkornsvete and KronJäst Surdeg Råg.