Is My Yeast Active?
Or is it dead?
Have you had your yeast sitting in the fridge or in your pantry for longer than you can remember?
I still remember that time I attempted to make pizza dough with active dry yeast that had been opened for a while and kept in the pantry (mistake #1).
I then proceed to add the yeast to the mixture without proofing it (mistake #2) and without testing the yeast (mistake #3).
After I let the dough rise for more than a few hours, I was rather surprised to see that my dough was still looking very…well…not risen.
I scratched my head, confused, but I just brushed over it and continued with making the pizza.
15 minutes later, I was digging into the soggiest, densest, rubbery pizza to ever appear on a dinner table.
From that day onwards, I learned 3 things; 1) always store opened yeast in the fridge, 2) always test yeast if it’s been a while since it’s seen the light of day and 3) that there are different types of yeasts out there.
So, if you’re about to make some delicious homemade bread (or pizza) and you’re wondering, ‘Is my yeast active?’, please don’t make the same mistake as me!
What is yeast?
Yeast is an important ingredient in bread as it makes our dough rise, resulting in a light, fluffy and delicious loaf.
Yeast is essentially a microorganism that is part of the fungus family. It needs food, warmth and moisture to thrive and grow in.
Yeast for bread comes in all different types. The most popular types of yeast is instant yeast (rapid yeast) and active dry yeast.
These types are really easy to find and will be available in your local grocery store.
Once opened, store your yeast in an airtight container in the fridge to maintain freshness. In the fridge, yeast can last up to 4 months if stored properly.
Yeast can also last a very long time in the freezer. If unopened, it can last years. If opened, it can last up to 6 months.
Fresh yeast can also be used for bread. Fresh yeast can be harder to get your hands on as it’s not commonly used.
If your local store has it, you will find it in the refrigerator section and it looks like a block of butter.
Fresh yeast is very perishable, so once bought, you need to store it in the fridge and use it within 2 weeks.
What yeast is best for bread comes down to what is available at your local supermarket, as all 3 types above work really well.
But, if you were to reach for one over the other, I would definitely recommend instant yeast.
It’s easy to store, lasts long and can be added straight to your ingredients without needing to activate it in water beforehand.
Active dry yeast, on the other hand, requires to be activated and proofed in water for around 15 minutes before it can be used.
It can be a bit time consuming waiting around for the yeast to proof, so going for instant yeast will save you an extra step.
How to test if yeast is active
There is one simple trick you can do to test if your yeast is active.
Take half a cup of warm water of around 37C/100F.
If it’s colder than that, the yeast won’t activate. If the water is too hot, it will kill the yeast.
I recommend using an instant read thermometer to give you an accurate reading of the temperature.
If you don’t have one, just make sure the water is hot enough to the touch.
To the warm water add a full sachet of yeast or 2 and a 1/4 teaspoons if your yeast is in a jar.
Add a teaspoon of sugar, stir the ingredients for a few seconds and let it rest for 15 minutes.
The yeast will feed off the sugar, so it’s vital you add it so it activates faster.
After 15 minutes it should look something like this. Foamy, frothy and full of bubbles.
My yeast started growing and bubbling very very fast and definitely didn’t need 15 minutes.
I just managed to get some photos taken in time before it spilled all over! But that’s a good sign as it means my yeast is nice and fresh.
If your yeast doesn’t look like this, then your it’s past its active days. Time to replace it with some fresh yeast!
Do keep a close eye on it because active yeast will bubble over very very fast.
Does yeast expire?
If you are wondering what to do with expired yeast, if it is unopened don’t throw it away!
Yeast lasts for a very long time and it can still be good after the expiration date.
If unopened and past the expiration date, chances are that it will still be good.
Open the jar, or one sachet and test it with the yeast activation test we just learned.
If it has been opened and has been sitting like that for a while, again, use the yeast test to determine if it is still active or not.
If the test shows that your yeast is still active, don’t throw that mixture away! Use it to make a loaf of bread.
So, there you have it! Now you know how to tell if your yeast is still active.
The yeast test is very easy and can be done in just under 15 minutes and is the most accurate way of telling if it is still fresh to use or not.
It’s worth taking the risk and going ahead making a loaf only to find that it doesn’t rise and comes out flat from the oven.
You will have wasted not just yeast but also some precious flour.
So, if in doubt, always test your yeast!