Yeast – The Mysterious Substance
Yeast is a strange beast, most people associate it with baking bread and brewing beer, but not a lot of people know what it is.
Anyone who has ever tried baking their own bread and failed will tell you that one of the main reasons was the yeast wasn’t given sufficient enough time to bud or was left for too long.
Yeast is actually a type of microorganism made up of one single cell that is allowed to grow through a process called budding, whereby a small yeast cell is grown from a larger one until it is mature enough to break off and repeat the same process over again.
For a yeast cell to grow, it needs sufficient food and the right environment, with an agreeable temperature and pH level, with either the presence or absence of oxygen, depending on what you’re planning on using your yeast for.
Yeast is used in the manufacturer of many foods and alcoholic beverages. Wine, beer and breads simply wouldn’t exist without this useful little microorganism. Yeast can convert into alcohol through a fermentation process. Yeast also produces carbon dioxide, which will ensure that your bread rises during the proofing stage.
What Is Involved In The Making Of Yeast?
As mentioned above, yeast is a microorganism that has to be grown in various conditions to produce different by-products such as alcohol and carbon dioxide that are used in the making of bread. However, this can be an incredibly difficult process to control, as most bread makers will attest.
You don’t actually need many ingredients to start manufacturing yeast, as you don’t really make yeast in the same way you do other ingredients. To make yeast, you have to take it from an existing yeast culture, of which there are a variety of different strains.
Growing Your Yeast
Yeast suppliers have many cultures that they can farm out to other places. If they want to breed more from a certain strain, they simply isolate those cells and wait for the process to take effect.
Yeast makers cultivate the precise conditions for growing yeast, knowing which conditions work better than others to get the desired results.
They usually contain the yeast cells in a small flask, adding water and food that usually includes sugar beet and sugar cane molasses. They make sure that the yeast is allowed just the right amount of oxygen and subjected to its preferred temperature. Soon the yeast grows and has filled the entire flask.
The amount of oxygen allowed into the chamber will drastically affect the yeast. Too little oxygen will cause the yeast to ferment, which then forms alcohol, which is detrimental to further yeast growth.
Eventually, the yeast is transferred to a larger chamber and fed even more to encourage further growth. The yeast is transferred to increasingly larger containers, eventually ending up taking up thousands of liters of storage space.
However, the bulk of this tank will be water with only a small percentage being pure yeast.
The reason for such a complex series of transfers is because growing yeast is such a tricky process, involving very precise changes in temperature and oxygen intake. One false move and the whole batch could be ruined.
Breeds Of Yeast – A Glossary
Larger bakeries might get their yeast from the process described above. However, most home bakers make their yeast from a sourdough starter, which doesn’t contain just yeast but a whole host of other bacteria which are great for making bread.
If you want to cultivate your own yeast, you will essentially be replicating the process used by the larger yeast manufacturers, taking great care to create the right climate for your yeast to thrive and produce the necessary carbon dioxide to make your bread rise.
Now we’re going to look at some of the different types of yeast that you can use that best suits the style of bread you’re looking to cultivate.
Active Dry Yeast
This yeast is at its most active and thriving, growing in the perfect conditions, ready to be used in making bread or any other leavened foodstuffs. However, once the food being fed to the yeast runs out, this activity will start to slow down.
To keep it preserved in this state, the manufacturer will dry it out, making it last for months on the shelf or in your cupboard.
To activate this yeast for your baking, you will need to add water to it. Active dry yeast should never be subjected to waters over 110 degrees Fahrenheit otherwise it will be killed. Accidentally deactivated yeast is a common problem for people baking their loaf from scratch.
This type of dry yeast is usually sold in a quarter ounce pouch or in a 4-ounce jar which, once opened, should be kept in a refrigerator.
Fresh yeast or cake yeast as it is commonly called, can usually be bought in a cake form and is very perishable. Ideally, it should be used within a few weeks of purchase, kept in the fridge and dissolved in water just before adding to your cake recipe.
To proof this yeast to see if it’s suitable for your recipe, put it into warm water with a dash of salt. If the yeast does not start to foam within 5 to 10 minutes, then it is not active and should be thrown out.
This type of yeast is the most popular form of yeast that you can find in most stores. It is easy to mix into a bread recipe as it does not need to be added to water for activation.
You can store this yeast in a dry, airtight storage container at room temperature until the expiration date on the label.
This type of yeast is often used in bread makers and is often labeled as ‘bread machine yeast’ so that customers can know what it’s used for when picking it up off the shelves.