Frequently Asked Questions (FAQ)

How many yogurt batches can I make from one starter?

Each starter prepares one initial batch of yogurt.

The finished yogurt can then be used as a starter for additional batches.

Dr. William Davis recommends restarting with fresh capsules after approximately 20 recultures.

While no scientific study has established a maximum number of recultures for homemade L. reuteri yogurt, food microbiology research indicates that repeated propagation of bacterial cultures can lead to genetic drift, selection of subpopulations, contamination, and changes in fermentation performance over time.

This means that one starter can produce up to 21 yogurt batches, allowing one starter set to produce up to 63 yogurt batches.

What do I need to prepare homemade yogurt?

To prepare yogurt, you will need:

• One of our starter cultures

• Milk

• A fermentation device capable of maintaining the recommended temperature

• A suitable carbohydrate source for the bacteria (milk lactose or, if preferred, inulin)

For best results, we also recommend using a kitchen thermometer to verify the actual fermentation temperature of your yogurt maker.

Many yogurt makers do not maintain exactly the temperature shown on their display.

Successful fermentation depends primarily on:

• the bacterial starter culture

• the fermentation temperature

• the type of milk

• the available carbohydrate source

• proper hygiene during preparation

Every starter set includes detailed step-by-step instructions and recipes.

Why is fermentation temperature so important?

Maintaining the correct fermentation temperature is one of the most important factors for successful yogurt preparation.

Temperatures that are too low may slow bacterial growth, while temperatures that are too high may reduce bacterial viability.

For this reason, we recommend checking the actual temperature of your yogurt maker with a thermometer.

Many yogurt makers differ from the temperature displayed.

Detailed temperature recommendations are included in every guide.

Scientific background

The growth and viability of lactic acid bacteria are strongly influenced by fermentation temperature.

Which yogurt maker do you recommend?

Any yogurt maker capable of maintaining a stable fermentation temperature can be used.

Because actual temperatures often differ from the displayed temperature, we strongly recommend checking your device with a thermometer before preparing your first batch.

Many customers successfully use yogurt makers from Luvele, Severin, Rommelsbacher and similar manufacturers.

The most important factor is not the brand but maintaining the correct fermentation temperature throughout the fermentation process.

Which type of milk should I use?

Many of our customers successfully prepare yogurt using:

• UHT milk

• Goat's milk

• Sheep's milk

• Coconut milk

Fresh milk should always be heated first to reduce naturally occurring bacteria that could compete with the starter culture.

Allow the milk to cool to 35°C (95°F) or below before adding the starter cultures.

The higher the fat content of the milk, the creamier the yogurt will generally be.

Lower-fat milk can also be used but typically produces a thinner consistency.

Milk with 3.5–3.8% fat is generally sufficient to produce a yogurt with a creamy consistency.

If you prefer a thicker, Greek yogurt- or skyr-style texture, you can add cream before fermentation.

Do I have to use inulin?

No.

Many customers successfully prepare yogurt using only milk and the starter culture without adding inulin.

If you would like to add a prebiotic, we recommend inulin, as this is the method recommended by Dr. William Davis and has consistently produced reliable results.

If you cannot tolerate inulin, you can simply prepare the yogurt without it, provided that your milk contains lactose.

The bacteria can use lactose, the naturally occurring milk sugar, as an energy source during fermentation.

We do not have sufficient experience with fermentation using lactose-free milk without adding inulin or another suitable carbohydrate source.

In this situation, fermentation may be less reliable because the bacteria require a fermentable carbohydrate to grow and multiply.

Why doesn't the first batch always look like yogurt?

It is completely normal for the first batch to have a different appearance.

Some first batches separate into whey and a thicker curd-like portion.

This does not necessarily mean that the fermentation has failed.

During the first fermentation, the bacteria are adapting to the new environment and their population is still relatively small.

For the second batch, simply use approximately 2 tablespoons of the thick portion as the starter for fresh milk.

Many customers find that the yogurt becomes noticeably thicker and more consistent from the second fermentation onward.

The separated whey does not need to be discarded.

It still contains valuable components such as peptides, minerals, lactic acid bacteria and water-soluble milk constituents and can be used in smoothies or shakes.

How do I access the e-book and yogurt recipes?

Every starter set includes access to a detailed digital guide.

The guide contains:

• step-by-step yogurt preparation instructions

• fermentation guidelines

• yogurt recipes

• practical troubleshooting tips

Access is provided via the QR code included in the package.

If you experience any problems accessing the guide, simply contact us at team@mygutmi.com and we will send you the link directly.

Can I contact you if I have questions?

Absolutely.

If you have any questions about:

• preparing yogurt

• choosing a yogurt maker

• selecting milk

• bacterial strains

• fermentation

• storage

• troubleshooting

or using one of our starter cultures, our customer support team will be happy to help.

Simply email us at:

team@mygutmi.com

We typically respond within one business day.

How should I store the starter cultures?

Store the starter cultures in a cool, dry place.

For optimal long-term storage, we recommend refrigeration.

The resealable pouch helps protect the cultures from moisture during storage and handling.

Is your packaging sustainable?

Yes.

Our starter cultures are supplied in resealable pouches made from 100% recycled plastic.

The packaging combines practical storage with a more sustainable use of materials while protecting the cultures from moisture throughout storage and transport.

Where are your starter cultures manufactured and quality tested?

Our starter cultures are produced in a GMP-certified manufacturing facility specializing in bacterial cultures under strict quality assurance procedures.

Each batch is monitored throughout production and laboratory tested to verify:

• identity

• purity

• viable cell count

• quality

before release.

Stability testing is performed to verify that the declared CFU count is maintained throughout the product's shelf life when stored as recommended.

This ensures that every starter culture meets the declared quality specifications before it reaches our customers.

What are Lost Species?

The term Lost Species describes bacterial species that are believed to be much less common in modern populations than they were historically.

Researchers have proposed several possible reasons for this decline, including the widespread use of antibiotics, highly processed diets, improved sanitation, reduced exposure to environmental microorganisms, and changes in childbirth and infant feeding practices.

Several bacterial strains included in our starter cultures, such as Limosilactobacillus reuteri and Bifidobacterium infantis, are frequently discussed in the scientific literature in this context.

Although the term "Lost Species" is not an official medical diagnosis, it has become increasingly common in microbiome research to describe microorganisms that appear to have declined substantially in industrialized societies.

Why don't probiotic bacteria permanently colonize the gut?

Most probiotic bacteria do not permanently colonize the human intestine.

Instead, they usually pass through the digestive tract while temporarily interacting with the existing gut microbiome and intestinal cells.

Whether a bacterial strain can establish long-term colonization depends on many factors, including the existing microbiome, diet, host genetics, immune responses, and competition with other microorganisms.

For this reason, many probiotic strains are consumed regularly if continued exposure is desired.

Why ferment yogurt instead of taking probiotic capsules?

Both probiotic capsules and fermented yogurt can be useful, but they are different ways of consuming beneficial bacteria.

During fermentation, bacteria multiply naturally in milk under controlled conditions, producing a fermented food that contains large numbers of living microorganisms together with fermentation products such as organic acids and bioactive compounds.

Many people therefore prefer homemade yogurt because they can control the bacterial strains, ingredients, and fermentation process themselves.

The optimal approach depends on personal preference and the bacterial strains being used.

What is microbial drift?

Microbial drift refers to the gradual changes that can occur in a bacterial culture when it is repeatedly propagated over many generations.

Several biological processes contribute to microbial drift, including:

• spontaneous genetic mutations
• selection of faster-growing subpopulations
• adaptation to the fermentation environment
• accidental contamination by environmental microorganisms

Over time, these processes can alter the composition and fermentation characteristics of the culture.

For this reason, Dr. William Davis recommends restarting with fresh starter cultures after approximately 20 recultures.

Although no scientific study has established a maximum number of recultures specifically for homemade L. reuteriyogurt, food microbiology research shows that repeated propagation of bacterial cultures can gradually change their characteristics.

Why choose yogurt made with Lost Species instead of traditional yogurt bacteria?

Traditional yogurt is typically made using bacterial species such as Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.

These bacteria are highly effective at fermenting milk and are widely used in conventional yogurt production.

They are also commonly present in many fermented dairy products, including yogurt and cheese.

Our starter cultures follow a different concept.

They contain carefully selected bacterial strains that are extensively studied in microbiome research and are frequently discussed in the scientific literature as Lost Species.

These bacterial species appear to be considerably less common in modern industrialized populations than they were historically.

The concept behind our starter cultures is therefore not simply to ferment milk, but to prepare yogurt using well-defined bacterial strains that are generally not included in conventional yogurt starters.

During fermentation, these bacteria multiply naturally in the milk, resulting in a fermented food containing large numbers of viable bacteria.

Many customers choose this approach because it allows them to prepare yogurt with specific bacterial strains that are not typically found in conventional yogurt products while maintaining full control over the bacterial strains, ingredients, and fermentation process.

Scientific Background

Several researchers have suggested that industrialization, widespread antibiotic use, dietary changes, improved sanitation, reduced environmental microbial exposure, and modern lifestyle factors may have contributed to a decline in the prevalence of certain bacterial species within the human gut microbiome.

The term Lost Species has therefore become increasingly common in microbiome research to describe bacterial species that appear to have become less prevalent in modern industrialized populations compared with historical or traditional populations.

Scientific References

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2. FAO/WHO. Guidelines for the Evaluation of Probiotics in Food. Joint FAO/WHO Working Group Report. London, Ontario, Canada. 2002.
   https://www.fao.org/3/a0512e/a0512e.pdf
3. Hill C, Guarner F, Reid G, et al. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the scope and appropriate use of the term probiotic.Nature Reviews Gastroenterology & Hepatology. 2014.
   DOI: 10.1038/nrgastro.2014.66
4. Walter J, Britton RA, Roos S. Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm. Proceedings of the National Academy of Sciences (PNAS). 2011.
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6. Marco ML, Sanders ME, Gänzle M, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nature Reviews Gastroenterology & Hepatology. 2021.
   DOI: 10.1038/s41575-020-00390-5
7. Sanders ME, Merenstein DJ, Reid G, Gibson GR, Rastall RA. Probiotics and Prebiotics in Intestinal Health and Disease: From Biology to the Clinic. Nature Reviews Gastroenterology & Hepatology. 2019.
   DOI: 10.1038/s41575-019-0173-3
8. Maldonado-Gómez MX, Martínez I, Bottacini F, et al. Stable engraftment of Bifidobacterium longum depends on individualized features of the resident microbiome. Cell Host & Microbe. 2016.
   DOI: 10.1016/j.chom.2016.09.001
9. Suez J, Zmora N, Zilberman-Schapira G, et al. Post-antibiotic gut mucosal microbiome reconstitution is impaired by probiotics. Cell. 2018.
   DOI: 10.1016/j.cell.2018.08.047
10. Sonnenburg ED, Sonnenburg JL. The ancestral and industrialized gut microbiota and implications for human health. Nature Reviews Microbiology. 2019.
    DOI: 10.1038/s41579-018-0116-9
11. O'Toole PW, Marchesi JR, Hill C. Next-generation probiotics: the spectrum from probiotics to live biotherapeutics. Nature Microbiology. 2017.
    DOI: 10.1038/nmicrobiol.2017.57
12. Blaser MJ. Missing Microbes. Henry Holt and Company. 2014.
13. Tamang JP, Watanabe K, Holzapfel WH. Fermented Foods in a Global Age. CRC Press. 2015.
14. De Vuyst L, Leroy F. Functional role of yeasts, lactic acid bacteria and acetic acid bacteria in fermentation processes. FEMS Microbiology Reviews. 2020.
    DOI: 10.1093/femsre/fuaa014
15. Giraffa G. Functionality of enterococci in dairy products. International Journal of Food Microbiology. 2003.