The Fresh Loaf

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How might one test their Instant Yeast?

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Yumarama's picture
Yumarama

How might one test their Instant Yeast?

I'm wondering if the jar of Instant Yeast I have has perhaps lost it's ooomph and wondered if there was a quick and simple test I can put it through? Unlike Active Dry Yeast that would foam and bubble profusely when added to a cup of lukewarm water, Instant just clouds up the glass but creates no foam. (This is precisely why I'm wondering if mine is dead, if it SHOULD have foamed and bubbled.)

nbicomputers's picture
nbicomputers

use warm water and a small amount of sugar    it should foam  if not its dead yours dosent sound to good

Yumarama's picture
Yumarama

So I did a test, using the following:




  • 2 oz of 90º warm water,

  • 1/8 tsp sugar,

  • 1/8 tsp Instant Yeast (Dated to Oct 2009)



and not much of anything. Zipped to the store and bought a new jar ($5!!) came home and redid the test, this time side by each,




  • 2oz of 90º water,

  • 1/8 tsp sugar

  • 1/8 tsp Instant Yeast (new one Dated to Oct 2010) 



10 minutes later, same results in both: nothing other than the smallest amount of fizziness on top. Certainly not the bubbly foamy stuff one would see with Active.  A glass of beer sitting on the counter for an hour would have more activity.


So, that's two different sources of Instant yeast, both do the same: nada.


Is this what Instant does in water but it's fine in the dough itself? Can someone else who has unquestionably working Instant do a similar test and see if their results are any different? 

xaipete's picture
xaipete

I've just started using instant yeast. I ordered SAF Red Instant Yeast from KA and I have to say that I am a complete convert. The stuff seems to work great in everything I bake without proofing. (I can't tell you how many times I've knocked over the container I was proofing in on the kitchen counter or the spoon I used to stir it with fell out; in either event, I seemed to create some mess and worry over how much yeast was missing in my dough.) I will never go back to active dry yeast. And, it's only $5.95 for a pound. I emptied the package into a mason jar and keep it in my refrigerator.


http://www.kingarthurflour.com/shop/detail.jsp?id=1458


--Pamela

RFMonaco's picture
RFMonaco

You can proof Instant Yeast the same as you would any yeast, but the water temperature has to change. Instant has finer granules and dissolves quickly, but it is still a dehydrated yeast:


QUESTION: I have several packages of Rapid Rise (Instant) Yeast with a date on the back of March 2, 2006 with the notation to use the yeast by that date for fastest rise. I'm hoping I don't have to make a trip to the store for more yeast. Can I still use this yeast for pizza dough with good results? Thanks


ANSWER: The yeast should still be good, but how were you storing it? It stays well beyond the expiration date if kept frozen or if stored in a cool, dark place in an unopened package.

You can test a small amount of it in 1/4 cup 120°F-130°F warm water, and a tiny amount of sugar. Make sure you quickly use the "proofed" amount in the recipe when it calls for adding the liquid.


FOLLOW-UP: Thanks Sarah, I tested the yeast and it is fine. Thank goodness with today's gas prices I didn't have to make another trip to the store for more yeast! I'm exaggerating, of course, but it was nice not having to make the trip.
- Chris From Ask Sarah, 3-25-06

Yumarama's picture
Yumarama

This time with 125º water. Back with the results shortly.

Yumarama's picture
Yumarama

125º water is a hell of a lot hotter than I'd have thought yeast would like. It's practically as hot as the tap water gets.


I repeated the above experiment with both the old and new yeast, put the glasses of yeasty water into a larger container and filled that with hottest tap water. I noted the water in the glass cooling rapidly, so figured putting them in a hot bath would keep them at or near 125º. After several minutes, there did seem to be a slight amount of foam gathering though still nowhere near the activity of Active yeast in 110º water.


So if this is any indication, I didn't actually need to rush to the store and buy more yeast. 


I will need to make a lot of yeast bread to go through all the yeast I have now.


I'd still like to see what other people's results are though, I have nothing to really compare this to except for itself.

suave's picture
suave

Properly stored instant yeast lasts a very long time.  That being said you can make a quick preferment.  Say, 1/2 cup of flour, 1/2 tsp yeast, 1/3 cup warm water (~100 F).  It should double, become very bubbly and be on a verge of collapsing in about an hour.

Yumarama's picture
Yumarama

... that I wasted the gas and money going to buy more yeast. Oh well ;)


Into the freezer that jar goes. 


Although the "older" yeast did raise this pseudo-dough a little slower than the "fresher" yeast, it was not by much and they both went well beyond double in a bit over an hour.


Thanks for the tip, suave.


But now I also feel rather foolish not having figured out to do this test on my own. Duh!! Put a bit of yeast in a bit of wet flour. How simple and utterly obvious.


Not enough coffee... yeah that's it, I'll blame it on lack of coffee.