Can Yeast Ferment Trehalose? What Bakers Need to Know

Trehalose has an unusual relationship with baker’s yeast.

Ordinary baking sugars such as glucose, fructose and sucrose can provide yeast with readily available carbohydrate during fermentation.

TREHA® trehalose behaves differently.

Commercial baker’s yeast, Saccharomyces cerevisiae, can ultimately metabolise trehalose, but externally supplied trehalose is used much more slowly than familiar fermentable sugars.[1–3]

That makes TREHA® particularly interesting in bread and other yeasted products.

Instead of simply behaving as another rapidly consumed yeast sugar, much of the added trehalose remains available in the dough to perform its other functions in the finished bread.

At the same time, yeast itself naturally manufactures trehalose inside its own cells, where it has an important role in energy storage and protection against environmental stress.[4–6]

The result is a fascinating distinction:

Trehalose outside the yeast cell is a relatively poor rapid fermentation substrate. Trehalose inside the yeast cell is an important natural protective carbohydrate.

Does Baker’s Yeast Ferment Trehalose?

Not readily under normal bread-making conditions.

Research into Saccharomyces cerevisiae has shown that externally supplied trehalose behaves very differently from glucose and other readily metabolised sugars.

Classic work on baker’s yeast found that trehalose could eventually support yeast growth, but only after a lag period of around ten hours.[1]

That is far longer than the active fermentation period of many ordinary bread-making processes.

Later research confirmed that S. cerevisiae possesses mechanisms for taking up and breaking down extracellular trehalose, but these pathways are more complex and slower than the pathways used for common fermentable sugars.[2,3]

For bakers, the important distinction is therefore not that baker’s yeast is completely incapable of using trehalose.

It is that TREHA® does not behave like an immediately available yeast food.

Why Does Trehalose Behave Differently?

Trehalose is a disaccharide composed of two glucose molecules joined by an α,α-1,1 glycosidic bond.

That structure is unusually stable.

Yeast cannot simply treat an intact trehalose molecule as though it were free glucose.

To use externally supplied trehalose, Saccharomyces cerevisiae has to transport or hydrolyse it through specialised pathways involving trehalose transport systems and trehalase enzymes.[1–3]

Research has identified several components of this system, including:

• transport of trehalose into the yeast cell
• intracellular trehalase activity
• extracellular or periplasmic trehalase activity
• hydrolysis of trehalose into glucose before subsequent metabolism.[2,3]

These additional steps help explain why trehalose is consumed much more slowly than ordinary fermentable sugars.

Trehalose Can Be Metabolised — Just Not Like Ordinary Sugar

The distinction between “cannot ferment trehalose” and “does not readily ferment trehalose” is important.

Saccharomyces cerevisiae does have the biological machinery required to utilise trehalose.[1–3]

Experiments using trehalose as the main carbon source have shown that yeast can adapt, hydrolyse the trehalose and eventually use the resulting glucose.

But this adaptation takes time.

That makes the behaviour very different from the rapid metabolism of glucose, fructose or sucrose that bakers normally associate with yeast fermentation.

Under ordinary bread-making conditions, TREHA® is therefore better understood as a functional ingredient in the dough than as a conventional yeast-feeding sugar.

What Happens to Sugar in an Ordinary Bread Dough?

Yeast does not depend exclusively on added table sugar.

In a dough containing sucrose, glucose or another readily fermentable sugar, those carbohydrates provide accessible substrate for fermentation.

But many traditional breads contain little or no added sugar.

Flour itself contains starch, and naturally occurring enzymes gradually break some of that starch down into smaller carbohydrates, particularly maltose.

Baker’s yeast can use these available sugars during fermentation.

This is why lean breads such as baguettes and many sourdough-style loaves can ferment successfully despite containing no added sucrose.

Trehalose does not need to replace this system.

It performs a different role.

Why This Is Useful in Bread

The fact that baker’s yeast does not rapidly consume TREHA® is one of the reasons trehalose can be useful in yeasted products.

If an ingredient is rapidly metabolised by yeast, much of it is converted during fermentation.

Trehalose remains available for longer and can contribute to the physical properties of the dough and finished bread.

TREHA® is used in bakery applications for functions including:

• helping maintain moisture
• supporting softer texture
• reducing dryness during storage
• supporting frozen-dough performance
• providing sugar solids with relatively little sweetness.

NAGASE commercial bread formulations consequently use TREHA® alongside conventional sugar rather than treating the two ingredients as interchangeable.[11]

For practical ratios and application methods, see How to Use Trehalose in Bread: Ratios, Yeast, Sourdough and Freshness →.

Trehalose Inside Yeast Is a Different Story

The most interesting part of the relationship is that yeast naturally contains trehalose itself.

Saccharomyces cerevisiae produces and stores trehalose as one of its principal reserve carbohydrates.[4]

Its concentration changes considerably depending on the condition of the cell.

Yeast tends to accumulate trehalose when exposed to environmental stresses such as:

• heat
• dehydration
• osmotic stress
• ethanol
• nutrient limitation
• freezing.[4,5]

Inside the cell, trehalose serves functions quite different from externally supplied TREHA® in a bread recipe.

It acts as both a carbohydrate reserve and an important component of the yeast’s stress response.

Trehalose Helps Protect Yeast Cells

Trehalose has long been associated with the ability of yeast to withstand difficult environmental conditions.

Higher intracellular concentrations are associated with protection of proteins and cellular membranes and with improved survival under stresses such as dehydration and freezing.[4,5]

This has considerable practical importance.

Commercial baker’s yeast often needs to survive:

manufacture → drying → storage → rehydration → fermentation.

Dry yeast is therefore a particularly striking natural example of trehalose protection.

NAGASE notes that baker’s yeast can contain trehalose at around 12% of its dry weight.[6]

The trehalose accumulated inside the cell helps protect the organism while it is dry and becomes part of the cell’s carbohydrate metabolism again when favourable conditions return.

The Trehalose Paradox

This creates what initially appears to be a contradiction.

Baker’s yeast contains substantial amounts of trehalose, yet it does not rapidly ferment TREHA® added to a dough.

The explanation is location and metabolism.

There is therefore no contradiction.

The yeast’s own trehalose is already incorporated into its internal metabolic and stress-response systems.

Trehalose added to the surrounding dough first has to enter or be broken down through other pathways before the yeast can make extensive use of it.[1–4]

Trehalose and Frozen Dough

The protective relationship between trehalose and yeast becomes particularly interesting in frozen dough.

Freezing can damage baker’s yeast and reduce its subsequent fermentative activity.

It can also damage the gluten structure responsible for retaining the gas generated during proofing.

Research into baker’s yeast has repeatedly found a relationship between intracellular trehalose and resistance to freezing.[5]

In one study of baker’s yeast produced under different growth conditions, greater trehalose accumulation was associated with improved cryotolerance and better stability in frozen dough.[5]

Other research has shown that externally supplied trehalose can also improve the survival of yeast cells during freezing and freeze-drying.[7]

Trehalose is therefore relevant to frozen dough in two related ways:

• yeast naturally uses trehalose as part of its own defence against freezing
• trehalose can also be used as a protective ingredient in systems exposed to freezing.

This is quite different from using TREHA® simply to provide fermentable carbohydrate.

Protecting the Fermentation System Rather Than Feeding It

This is one of the most useful ways to understand TREHA® in frozen bakery products.

Its contribution does not need to come from increasing yeast activity before freezing.

Instead, trehalose can help protect biological and food structures from some of the stresses created by freezing and frozen storage.

That distinction is important because frozen dough needs more than carbohydrate.

It needs viable yeast, an intact dough structure and sufficient gas-retention capacity after thawing.

Trehalose's established cryoprotective properties make it relevant to this wider system.

Sourdough Is More Complicated

Commercial baker’s yeast provides a relatively simple microbial system dominated by Saccharomyces cerevisiae.

Sourdough is different.

A mature starter contains a complex community of yeasts and lactic-acid bacteria, and those organisms do not all metabolise carbohydrates in the same way.

This means that the behaviour of added trehalose in sourdough cannot be predicted solely from the behaviour of commercial baker’s yeast.

Sourdough Bacteria Can Use Trehalose

Fructilactobacillus sanfranciscensis is one of the best-known lactic-acid bacteria associated with traditional sourdough.

Recent comparative research found considerable variation in the carbohydrates that individual strains could use.

In a study of 14 F. sanfranciscensis strains, approximately 79% were able to utilise D-trehalose.[8]

That means trehalose introduced into a sourdough system may become available to parts of the bacterial community even though Saccharomyces cerevisiae itself uses external trehalose comparatively slowly.

The precise result will depend on the microorganisms present in a particular starter.

This is one reason sourdough should be thought of as an ecosystem rather than simply a yeast dough with a longer fermentation time.

Trehalose Can Also Protect Sourdough Cultures

Trehalose has another potential role in sourdough technology: protecting the starter organisms themselves.

Research into freeze-dried wheat sourdough found that adding trehalose before preservation improved microbial survival, with particularly strong protection of lactic-acid bacteria.[9]

This mirrors the protective role seen in baker’s yeast and other microorganisms.

Trehalose can therefore interact with sourdough in two quite different ways:

• some starter organisms can metabolise it
• trehalose can help protect microorganisms during drying and preservation.[8,9]

This is particularly relevant to commercial starter cultures and dried sourdough systems.

Do All Yeasts Treat Trehalose the Same Way?

No.

Saccharomyces cerevisiae is only one yeast species.

Yeasts are a highly diverse group of microorganisms, and their ability to ferment trehalose varies considerably.

Comparative research has identified yeast species capable of fermenting trehalose much more readily than commercial baker’s yeast.[10]

The broad question:

“Can yeast ferment trehalose?”

therefore has no universal answer.

Some yeasts can.

The more useful bread-making question is:

“Does ordinary commercial baker’s yeast rapidly ferment externally supplied TREHA®?”

The evidence indicates that it does not.[1–3]

Fermentation and Functionality Are Different Things

This distinction is central to understanding trehalose in baking.

A sugar can contribute to a bread recipe without needing to serve primarily as yeast food.

TREHA® has functional properties relating to:

• moisture
• starch
• protein structure
• freezing
• sweetness
• storage quality.

Those functions remain relevant even where little of the trehalose is fermented during the normal proofing period.

That is why TREHA® should not simply be viewed as an unusual substitute for sucrose.

It is a functional baking ingredient with a different relationship to yeast.

Why Professional Formulations Can Use Both Sugar and TREHA®

NAGASE bakery formulations illustrate this distinction clearly.

Its brioche formulation, for example, contains both conventional sugar and TREHA®.[11]

The two ingredients are not being asked to perform exactly the same job.

Conventional sugar remains part of the normal enriched-dough formulation, while TREHA® provides additional functional properties in the dough and finished bread.

This is a useful model for understanding TREHA® more generally:

ordinary fermentable carbohydrate and trehalose can work alongside one another rather than competing for the same role.

For practical formulation guidance, see How to Use Trehalose in Bread →.

The Key Points

The relationship between trehalose and yeast can be summarised quite simply.

Commercial baker’s yeast does not rapidly use externally supplied trehalose in the way it uses glucose or other readily fermentable sugars.[1–3]

Saccharomyces cerevisiae can nevertheless metabolise trehalose through specialised transport and trehalase pathways given sufficient time.[1–3]

Yeast naturally manufactures trehalose inside its own cells, where it acts as a reserve carbohydrate and helps protect the organism against environmental stress.[4–6]

That protective role is particularly relevant to dried yeast and frozen dough.[5,7]

Sourdough is more complex because its lactic-acid bacteria and yeasts vary in their ability to use trehalose.[8]

And across bread applications, the most important distinction is this:

TREHA® does not need to be rapidly fermented to be useful in a yeasted dough.

Its value lies in what it can contribute to the food as a functional ingredient.

Using TREHA® in Bread and Baking

Trehalose UK supplies genuine Japanese TREHA® manufactured by Nagase Viita Co., Ltd., formerly Hayashibara.

For practical bread ratios, sourdough guidance and worked examples, see:

How to Use Trehalose in Bread: Ratios, Yeast, Sourdough and Freshness →

For cakes and other baking applications:

How to Use Trehalose in Baking →

For general starting ratios:

How Much Trehalose Should I Use? →

For the wider science of freshness and storage:

How Trehalose Helps Food Stay Fresh for Longer →

For product-development or commercial enquiries:

Contact Trehalose UK →

sales@trehalose.co.uk

References & Further Reading

[1] Arnošt Kotyk and Dana Michaljaničová. 1979. “Uptake of Trehalose by Saccharomyces cerevisiae.” Journal of General Microbiology 110, no. 2: 323–332. DOI: 10.1099/00221287-110-2-323. The study reports that external trehalose supported growth only after a prolonged lag period of approximately ten hours. microbiologyresearch.org

Read the study → Microbiology Society

[2] Arghya Basu, Soma Bhattacharyya, Paramita Chaudhuri, Subhabrata Sengupta, and Anil K. Ghosh. 2006. “Extracellular Trehalose Utilization by Saccharomyces cerevisiae.” Biochimica et Biophysica Acta 1760, no. 2: 134–140. DOI: 10.1016/j.bbagen.2005.11.016. Examines the extended lag phase and the role of extracellular trehalase in converting trehalose into glucose before subsequent metabolism. ScienceDirect

Read the study → ScienceDirect

[3] Matthieu Jules, Gemma Beltran, Jean François, and Jean Luc Parrou. 2008. “New Insights into Trehalose Metabolism by Saccharomyces cerevisiae: NTH2 Encodes a Functional Cytosolic Trehalase, and Deletion of TPS1 Reveals Ath1p-Dependent Trehalose Mobilization.” Applied and Environmental Microbiology. DOI: 10.1128/AEM.00557-07. Describes the transport and trehalase pathways involved in internal and external trehalose metabolism. ASM Journals

Read the study → Applied and Environmental Microbiology

[4] Jean François and Jean-Luc Parrou. 2001. “Reserve Carbohydrates Metabolism in the Yeast Saccharomyces cerevisiae.” FEMS Microbiology Reviews 25, no. 1: 125–145. DOI: 10.1111/j.1574-6976.2001.tb00574.x. Review of trehalose and glycogen metabolism, energy storage and the yeast stress response. Wiley Online Library

Read the review → Oxford Academic

[5] Pierre Gélinas, Gisèle Fiset, Anh LeDuy, and Jacques Goulet. 1989. “Effect of Growth Conditions and Trehalose Content on Cryotolerance of Bakers' Yeast in Frozen Doughs.” Applied and Environmental Microbiology 55, no. 10: 2453–2459. DOI: 10.1128/AEM.55.10.2453-2459.1989. Higher trehalose synthesis was associated with improved cryoresistance and frozen-dough stability. PubMed Central (PMC)

Read the full study → PubMed Central

[6] Nagase Food Ingredients. “Is Trehalose Safe?” Manufacturer information describing the natural occurrence of trehalose in foods and baker’s yeast, including its substantial presence in dry baker’s yeast. Nagase Foods

NAGASE TREHA® information → NAGASE

[7] Diniz-Mendes et al. 1999. “Preservation of Frozen Yeast Cells by Trehalose.” Biotechnology and Bioengineering 65, no. 5: 572–578. Research showing improved survival of yeast during freezing and freeze-drying when trehalose was incorporated into the preservation system. Wiley Online Library

Read the study → Wiley Online Library

[8] “Comparative Genomics Reveals Genetic Diversity and Variation in Metabolic Traits in Fructilactobacillus sanfranciscensis Strains.” 2024. Microorganisms 12: 845. DOI: 10.3390/microorganisms12050845. In carbohydrate-utilisation testing, 78.57% of the 14 strains examined were able to utilise D-trehalose. PubMed Central (PMC)

Read the study → Microorganisms

[9] Raquel Facco Stefanello et al. 2018. “Trehalose as a Cryoprotectant in Freeze-Dried Wheat Sourdough Production.” LWT 89: 510–517. DOI: 10.1016/j.lwt.2017.11.011. Trehalose improved microorganism survival during freezing, freeze-drying and subsequent storage, with particularly strong protection of lactic-acid bacteria. ScienceDirect

Read the study → ScienceDirect

[10] R. J. Bouthilet, Nora E. Neilson, E. M. Mrak, and H. J. Phaff. 1949. “The Fermentation of Trehalose by Yeasts and its Taxonomic Implications.” Journal of General Microbiology 3, no. 2: 282–289. Comparative work demonstrating that trehalose-fermenting ability differs substantially between yeast species. microbiologyresearch.org

Read the study → Microbiology Society

[11] Nagase Food Ingredients. “Brioche.” Professional TREHA® formulation containing conventional sugar and TREHA® together, illustrating their different functions in enriched bread. Nagase Foods

View the NAGASE brioche formulation → NAGASE Food Ingredients