Different types of yeast: explained

January 22, 2020 6:13 am Published by 2 Comments

Today, we’re looking at different types of yeast. We were contacted by a customer recently, asking about the differences between the yeasts she saw mentioned in recipes: fresh, active, dried and wild. She was also looking for some general advice on baking bread. We thought we’d share our expertise, not only with her, but with the rest of you!

What type of yeast do you need?

What type of yeast is this?

What’s yeast?

Let’s start at the beginning: what’s yeast?

Yeast is a single-celled microorganism that’s classified as part of the fungus family. There are at least 1,500 species currently recognized (don’t worry, we’re not planning to discuss each one in this blog). They reproduce asexually and (in the species in which we are particularly interested) convert carbohydrates to carbon dioxide and alcohol in baking and brewing.

Yeast is a living organism. Whether you’re buying fresh, dried or instant yeast, or encouraging the growth of wild yeast, you’re dealing with a living thing. For some vegans, this poses a vexed problem. However, the majority of vegans do eat yeast, reasoning that the organism is not capable of suffering or of being exploited.

What’s wild yeast?

Surprising as it may sound, wild yeasts are everywhere – in the air, on our bodies, in trees, on surfaces – on everything we touch and eat. They flourish wherever they can find food, taking up residence on fruits and vegetables and feeding off the sugars there. You might also hear them described as ‘ambient/indigenous/natural yeasts’.

Before we worked out how to capture and cultivate yeast, we relied on attracting wild yeasts to our baking and brewing mixtures. Some still do. They simply set their ‘starter’ (for example, their sourdough starter of flour and water) in a covered bowl – under a fruit tree, ideally, or, near to some wild flowers – cross their fingers, maybe say a quick incantation, and hope the wild yeasts descend.

All this is all a bit hit and miss for most of our customers, of course. If you’re determined to use wild yeasts, you’ll be relieved to know that some of them have been captured and are available for sale from people more specialist than us. Wild yeast is often considered to give particularly flavoursome and interesting results (and is generally just a little more ‘hip’ than its tamer cousins).

What’s tame yeast?

It’s the tamer cousins you’ll buy in mainstream shops (and from us). When people talk about yeast, this is generally what they mean: fully domesticated yeast, of the strain saccharomyces cerevisiae (sometimes also referred to as ‘selected/inoculated/cultured’ yeast). It’s a strain that does occur in the wild, but which was long ago captured and cultivated for its efficiency in delivering fermentation. Fresh yeast, active yeast, dried active yeast, dried yeast – wherever you see these called for, it will be ‘tame’ yeast you need.

What’s active yeast?

‘Active’ simply means that the yeast is not dead – it will work. Active yeast can be fresh or dried. The important thing is that it needs to be reactivated – it’s a kind of ‘sleeping’ or dormant yeast.

What’s fresh yeast?

Fresh yeast, sometimes called ‘cake yeast’ or ‘compressed yeast’, is a block of fresh yeast cells. Resembling discoloured margarine, it has a texture similar to that of an eraser and crumbles nicely. It has a strong ‘yeasty’ smell and many professional bakers believe that it produces the most flavoursome results. However, it’s fairly expensive, only has a shelf-life of about two weeks and needs to be stored in the fridge, meaning that it’s only really suitable for people who are continually baking.

You might also hear this referred to as ‘fresh active yeast’. To reactivate it, you must mix it with liquid before adding other ingredients.

It would be unusual to come across a recipe for non-professionals calling for fresh yeast. If you want to start using it, check out the information available online to work out how to do so.

What’s dried yeast?

Dried yeast comes in the form of little pellets – dried dormant granules of yeast. Dried yeast is pretty inexpensive, has a long shelf life and can be stored at room temperature. It’s dried yeast that will be referenced in the recipes most of us come across – and it’s this that we sell at Naturally Good Food.

However, there is one more complicating factor….

What’s dried active yeast?

Dried active yeast is the name given to dried yeast that needs to be reactivated in water before you add other ingredients. (Note: this isn’t an onerous task – it’s a standard part of most recipes.)

What’s instant dried yeast?

Instant dried yeast is something a little different. This type of yeast has much smaller granules than ‘dried active yeast’, which means that you can add it direct to dry ingredients, without having to start it off in water first. It’s so small that it disintegrates instantly, and is thus reactivated without the need for an initial stage in water.

Other names for yeast

There are other proprietary names for dried yeast, such as ‘Easy Bake Yeast’, ‘Fast Acting Yeast’ and so on. These might have other ingredients added, such as ascorbic acid, which speeds up the bread-making process. The only thing that matters is that you can establish what kind of dried yeasts these are. To do so, check the instructions on the packet. Do you have to add it to water first? Then it’s dried active yeast. Can you add it straight to the ingredients? Then it’s instant yeast.

What if you have the wrong kind of yeast?

What if you’ve only got instant yeast, but the recipe calls for dried active yeast – or vice versa? There’s no need to despair: the internet is full of conversion advice for those needing one type, but only possessing another. It’s not hard to convert and the results will be just as you expect. In reality, dried active yeast and instant yeast are used interchangeably by most bakers, with just minor tweaks to the recipe.

Naturally Good Food’s yeasts

At Naturally Good Food we sell three kinds of instant yeast:

Bioreal’s organic instant dried yeast, in sachets.

Allinson’s easy bake yeast, in sachets.

Dove’s Farm quick yeast.

You might also be interested in our sourdough starter – a dried culture of natural yeasts – from Andrew Whitley.

General bread-baking tips

We count keen bread-makers among our staff at Naturally Good Food – over the years, they’ve amassed a wealth of experience. Perhaps this blog below might be useful for anyone struggling at this damp and dismal time of year?

It’s cold out there and my bread won’t rise 

Naturally Good Reads v2

 

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This post was written by Yzanne

2 Comments

  • Kathryn Sharp says:

    Ref: ‘They simply set their ‘starter’ (for example, their sourdough starter of flour and water) in a covered bowl – under a fruit tree, ideally, or, near to some wild flowers – cross their fingers, maybe say a quick incantation, and hope the wild yeasts descend’;

    The yeasts are naturally part of the wheat grain’s micro-flora not from another source like fruit trees or flowers! A starter is as simple as flour and water and time. And no incantations necessary!

    • Yzanne says:

      Hi Kathryn – you’re right about the incantations (apologies, that was a little tongue-in-cheek)! That’s an interesting point about the yeast being naturally present – my research had led me to believe that the yeast needed to be attracted from elsewhere. Does anyone else have any views on this?

      Best wishes,

      Yzanne Mackay
      Writer and Editor
      Naturally Good Food

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