All About Yeast

All you need to know about baking with yeast!

If there’s one thing that intimidates new bakers and sometimes even experienced ones, it has to be baking with yeast. To be honest, when I first started baking bread, I too found recipes with yeast a bit overwhelming. There was always this huge scope for error but I realized most of the fear comes from not understanding the science behind an ingredient. After various “experiments” in the kitchen, I’ve come to understand how yeast works and now, it’s really just another ingredient on the table. In fact, if you want to start making truly good bread at home, you have to find your way around yeast.
This article will help you understand what yeast is, how it works, and everything you ever wanted to know about this seemingly complicated ingredient. I’ve addressed the most frequent questions that I receive and the common mistakes we all make while working with yeast.

Let’s begin with the most basic question

What is yeast?

Yeast is a living organism that thrives on food and moisture. In bread baking, when yeast is added to the dough, it reacts with the sugars in the flour and releases carbon dioxide which expands the dough and thus causes it to rise. Thus the yeast serves as a ‘leavening agent.’

Proofing Dough.

In all the crusty slices of pizza, fluffy goodness of cinnamon rolls, or the pillowy bites of hot buns, yeast is the magic ingredient.

How is yeast different from other leavening agents?

While yeast basically causes the same reaction as baking powder and baking soda in a recipe, ie., the production of carbon dioxide, all three actually produce different results mainly owing to the process that each go through to become activated. While baking powder and baking soda are chemical agents specially formulated for quick results in baking, yeast leavens dough via a biological process and thus takes much longer – this slow and natural fermentation also produces residual alcohol that affects the final texture and flavor of the dough.

All about yeast.

Which is why when we walk past a bread factory, our senses are assaulted by that wonderful yeast smell that we have all come to associate with fresh bread.

Types of Yeast

While there are several types of yeast such as brewers yeast used to make beer, nutritional yeast used in cooking, and wild yeast/sourdough to make naturally fermented foods, in this article we’re only looking at the different forms of commercially available ‘bakers yeast.’

Fresh yeast/cake yeast/ block yeast – Available in cake form, fresh yeast is often used in bakeries, and is not the preferred choice of home bakers because of its highly perishable nature. At best, fresh yeast will last for 10-12 days, refrigerated. Fresh yeast is usually brown-gray in color and is soft and crumbly. The best way to check if it has gone bad, is to check for signs of mold on the surface. If the yeast looks dark brown, hard or crusty, then it’s best to discard it. It’s also not available easily and you may find it in a local bakery or select supermarkets.

Active Dry yeast- Active dry yeast is just fresh yeast that has been pressed and dried. This removes the moisture and makes the yeast dormant till it’s rehydrated or mixed with warm water. This increases the shelf life of the yeast and thus makes it easier to store. Active dry yeast was infact developed as a shelf stable product during World War II so that the US Army could make bread without having to refrigerate fresh yeast.

types of yeast.

Instant Yeast – Also known as rapid-rise yeast or fast-acting yeast or bread machine yeast in some countries, instant yeast is basically the same as active dry yeast, however it is just milled into finer particles. The smaller granules mean that the instant yeast can be added directly to the flour and does not require to be proofed in warm water separately and thus is the fastest acting yeast to make bread.


Here’s a visual representation of the differences between the 3 kinds of yeast

table on yeast properties.

How to Proof Yeast

Proofing yeast is the simple test to check if your dormant yeast (fresh or active dry,) is still alive and able to start the fermentation process and a lot of recipes include this step as part of the recipe instructions. Proofing only needs 3 ingredients – yeast, sugar and warm water.

Proofing Yeast.

To proof, take the mentioned quantity of yeast in your recipe in a bowl. Add to it 1 tsp sugar and ¼ cup of warm water. Stir gently with a spoon, then cover the bowl, and leave the yeast aside for 10-15 minutes to do its thing. During this time the yeast will start to create gas bubbles/foaming. Which indicates the yeast is active and good to use. You can add this yeasted water to your flour and continue with the recipe.

Watch this fascinating time-lapse of this process here – 30-second time-lapse of yeast proofing.

Since you’ve used a tsp of sugar and ¼ cup of water for the yeast, you will need to adjust that much quantity of both ingredients in your recipe accordingly.

Common Proofing Mistake

The most crucial thing while proofing yeast to keep in mind is the temperature of the water. This is where most people go wrong. Yeast requires warm temperature to start working, however, very hot water can kill yeast. Yeast continues to ferment till it is exposed to high heat during the baking process. Thus if it is exposed to too much heat earlier, it will be rendered ineffective even before it has had a chance to leaven your dough. A general rule of thumb to follow is to keep your water lukewarm or mild enough so that when you put a finger in, you don’t retract or wince. For the more scientifically inclined –

Correct temperature for proofing yeast

Fresh Yeast – 30-35 degree C
Active Dry or Instant Yeast – 35-40 degree C.

How to identify expired yeast?

If during proofing, the yeast does not bubble or foam, it’s probably old/expired or just bad from not being kept in ideal conditions. It’s best to not use this yeast and start over the proofing process with a fresh pack of yeast.
Even though instant yeast does not require to be proofed, I recommend doing it anyway to be sure that the yeast is good to use and not waste the effort of kneading and proofing the dough.

How much to use

It’s important to use yeast in the right quantity in a recipe to get good results. Too little yeast may result in the dough not rising sufficiently resulting in a hard, chewy or dense bread wheras too much yeast may lead to dough overproofing and leaving a fermented smell or taste, cracking, breaking, or sinking of bread.

As a standard, here’s the quantity of each kind of yeast I recommend to use for 500g flour.

Instant Yeast – 2 tsp (approx 8 gms)
Active Dry Yeast – 2.5 tsp
Fresh Yeast – 12 gms

Basically for every tsp of active dry yeast, you can use ¾ tsp of instant yeast and twice the quantity of fresh yeast.

Brands of Yeast

After reading so much about yeast, you’re probably still wondering, “But what brand of yeast should I buy?”

Types of yeast.

Until even 5 years back, there weren’t too many choices to buy good yeast if you lived in India. However, over the years, with demand, availability of packaged yeast has also gone up. Here are some Indian brands that I have used and liked. Please note that this is not a comprehensive list and there are many more brands in the market that may give good results too. You could click directly on the links to purchase these brands.

And now that we’ve conquered the yeast beast, let’s look at some really simple bread recipes you can begin your bread baking journey with:

Have more questions about yeast. Ask me here on Instagram or leave me a comment under this post!

The next article coming up on the blog is on “Tips and Tricks to make the perfect bread.” Subscribe to the blog to ensure you don’t miss out on any articles!