The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Fleischmann's "Instant Dry Yeast"

RiverWalker's picture

Fleischmann's "Instant Dry Yeast"

so my fiancee's dad does a little baking, and got a really good deal on some yeast at sam's,(like, two pounds for under 5 bucks) but way more than he can use(since he doesn't bake bread all that much) so he gave me some. great! I figure it'll be a clear bag of basic, run of the mill active dry yeast.  no problem.

instead I get a vacum packed 1lb brick of "Instant Dry Yeast".  now this is good, isn't it? I mean its the stuff that the books seem to prefer, not the weird single rise stuff or whatever, right?

the ingredients listed are "yeast, sorbitan monostearate, ascorbic acid".

if it is the regular stuff (Fleischmann's equivalent of the "SAF Red" that everyone seems to love) then thats extra awesome, just slightly concerned that theres a good REASON it was so cheap, aside from being at sams club. 

flournwater's picture

Somewhere on the package there will be an expiration date.  Once that date has passed you won't find much use for the yeast that remains in the package.  I often buy yeast in bulk at COSTCO because, eventhough I can't possibily use it all in the period of time between when I take it home and the expriation date, it still saves me a substantial amount of hard earned cash, given the price of one of those little packages in the super market.  You can probably stretch the usefulness of the yeast past its expirtion date.  You simply have to proof it with some water and a bit of sugar to see if it's active in that medium.  When it stops reacting to the proofing test it's time to replace it.

subfuscpersona's picture

For best performance, instant dry yeast (IDY) should be added directly to dry ingredients. Unlike active dry yeast (ADY), IDY should not be dissolved in water prior to use. The original poster has IDY.

For best performance, active dry yeast (ADY) should be dissolved in a small amount of warm water prior to use. You do not need to add sugar to the water in which the ADY yeast is dissolved unless you have serious doubts about it's viability.

For a more extended discussion of IDY vs ADY, see

flournwater's picture

My reference to "proof testing" was not intended as a recommended process in the peparation of a dough; I simply meant that to determine if the yeast taken from storage was still lively, a proof test of a sample would provide an indicator as to whether or not the bulk of the yeast was worthy of being incorporated into the formula.

saraugie's picture

"For best performance, instant dry yeast (IDY) should be added directly to dry ingredients."

I think I've read in P. Reinhardt's ABED, that he likes to put IDY into the liquid first before putting into the mix.  I'm sure I've read it by one of the experts and have adapted the method.  I know for sure that most experts agree that IDY is preferable to ADY.

RiverWalker's picture

yeah, I've read similar things.  I was mainly not positive that this was the stuff that they were referring to.  but apparently it is, so I'm quite happy about it.



proth5's picture

is the same yeast that is marketed in small packages as Fleischmann's "Rapid Rise Yeast"  or "Bread Machine Yeast" (or as you put it "the weird single rise stuff")  They are (and I'm going to say this advisedly after the great powdered sugar debate, but we are working with a brand name, here) the exact same yeast.

Fleischmann's markets this yeast in 1 pound packages through Sam's Club.

You may wish to inspect the expiration dates, if it seems to be too inexpensive.  But even so, if they are not too far gone and the package was stored under good conditions, you have a good, general purpose instant yeast.

Hope this helps.

RiverWalker's picture

well the expiration date is Dec 1 2011, so no problem there.  I haven't actually opened it yet, so no issue with performance or anything, just trying to avoid annoying surprises.

I thought I had read somewhere that one of the types of yeast was weird in some way, or that it was made with extra additives or something that made it so it was very effective in some situations, but for most bread, crapped out after the bulk rise or something.

did I dream that up or is it not really an issue or bad info or what? I thought I had read it in BBA but I am not seeing it there now... so maybe I did just imagine that part....

as a bottom line, is this the stuff the books regard as interchangable with Active Dry Yeast, but a tad bit more potent(25%?), and more friendly to not being hydrated first(though, apparently some people find that to not be neccessary with active dry either....)


proth5's picture

What you have in your hands is "instant yeast."  I'm not sure about the content of "the books" you mention (the books that I have always specify the exact type of yeast - instant, or active dry, or most often for my books, fresh for the formula at hand), but instant yeast and active dry yeast  are different.  Mostly they are different in how they are processed during manufacturing so that active dry yeast has more dead yeast in it and is not granulated as finely (Fleischmann's claims they are different strains of yeast - other reputable people disagree.)  I have heard references to substituting active dry for instant by increasing the quantity.

Because of the larger granules, generally we like to dissolve active dry in water prior to using it, but, yes, as you mention, some recipes do not require it.

Fleischmann's (and Lesaffre - why does nothing surprise me?) is now marketing a "pizza crust yeast" that contains dough conditioners.  These relax the dough so that people who cannot wait ten minutes after mixing dough can shape a pizza immediately.  This is certainly not interchangeable, but that's not what you have.

You may also have heard of "osmotolerant" yeast.  When in a bread with a high sugar content, the sugar actually has the effect of pulling water away from the yeast and decreasing its effectiveness.  The Lesaffre yeast company markets "SAF Gold" which performs better in a high sugar environment.  This is not the same as the yeast you have.

Lesaffre (who produces SAF as well as Red Star yeasts) also has slightly different names and their own strong feelings about what yeast is called what and how you ought to use their yeasts, but you have Fleischmann's. 

I will have to say here that researching yeasts as marketed to professionals (usually in large sizes) and to home bakers is quite informative.  Kind of like a "Marketing 101" class. But I digress.

Fleishmann's Rapid Rise Yeast/Bread Machine Yeast has recipes designed by Fleischmann's (and others) where they:

  • Use a very high baker's percentage of yeast, and
  • Use very warm water so that the yeast will begin to work very quickly

Both of these contribute to the "rapid rise" of the breads.  They were designed for "busy people" who wanted to get breads in the oven quickly and were prepared to sacrifice some taste and texture to do that.  These recipes (not particularly the yeast) require only a short rest before shaping.  Almost all of the fermentation takes place in the final "proof."

Because I seldom use commercial yeast anymore, I keep a little jar of Bread Machine Yeast in my freezer (not worth buying more - I actually won't get through that jar by the time it is well and truly dead.)  It is not "weird" in any way and has not (as you put it )"crapped out" after the bulk rise (ferment).  I have made some very nice breads with it.

The ascorbic acid in the Rapid Rise, Bread Machine, and Fleischmann's Instant dry yeast will have some impact on the gluten in your flour, but it will be minor, and I doubt that effect can be elevated to the status of "crapping out."

An interesting aside is that "deactivated dry yeast" is sold on its own as a dough conditioner, so some bakers suggest that in areas like laminated doughs (croissants, for example) that it is actually beneficial to use active dry yeast as it makes the doughs easier to roll.

I don't know if this is bottom line enough for you, but should help you understand a bit more about the general purpose instant yeast your fortunate future father in law has purchased for you.

bobm1's picture

this thread has been foaming around in my brain for some time. i'm curious, are active dry and instant interchangeable in a formula or are they specialized 'tools' chosen to fit the 'job', such as osmotolerant yeast for enriched doughs. baker's preference not withstanding, how is the resulting dough affected when one is substituted in equal amounts for the other?

as is often the case, my primary intent is to offer some tidbit of value to these discussions and, without exception, i learn something new.

as to the self life of instant yeast i would offer this.. for what it's worth. at a work shop i attended some time ago a renowned baker (who's name was not PR) said that instant yeast has a virtually unlimited shelf life. the expiration date is placed on the package only because the agencies that govern such things require it.  properly handled it should last indefinitely.

having only been baking for one year, i find that i am still quite soggy behind the ears.

thank you all for your towels of knowledge :)


subfuscpersona's picture

In late 2006 I purchased 2 one-pound vacuum sealed packages of Fleishmann's instant dry yeast (IDY) - exactly the kind you've got. Prior to that I used Red Star instant dry yeast. I found no performance difference between the two brands for bread baking.

The expiration date on both my packages of Fleishmann's IDY is Oct 2008. I finished the first package approximately a year after the expiration date. I found no performance difference between the yeast at the beginning of use (2 years prior to expiration date) and at the end (about a year after the expiration date).

I am currently using the 2nd bag; it was opened a year after the expiration date. I find no performance difference between this yeast and the same yeast used two years before the expiration date.

I do not use a lot of yeast in my bread dough - typically about one teaspoon per pound of bread dough. With the long rising techniques that I prefer, the dough rises reliably and bakes well, with good oven spring.

The morale of my experience is that, if stored correctly, instant dry yeast (or active dry yeast) has a long life. The longest I kept a one pound bag of dry yeast was five years (that was a bag of active dry yeast). Again, there was no perceptable degradation in the yeast's performance during this time. My experience is echoed in many bread baking forums and mailing lists. It is not uncommon for home bakers to use the same bag of dry yeast for up to five years with good baking results throughout the yeast's life span.

The key to long life for dry yeast is correct storage, which means storing it in the freezer. On purchase, I put the unopened bag of yeast in a sturdy zip lock bag and put it in the freezer. Once it is opened, the top is closed with a small clamp (the kind you get in a stationary store) plus the bag is always in the zip lock bag. If you're careful to keep moisture out of the yeast and always keep it in the freezer, you can expect it to remain vigorous for a long time.

For convenience, some people keep a smaller amount of dry yeast in a small, tightly closed jar or container in their refrigerator. I prefer to keep all of it in the freezer, as I only bake about once a week. I do keep a few small measuring spoons (teaspoon, 1/2 teaspoon and 1/4 teaspoon) in the zip lock bag along with the yeast.

pmccool's picture

I've purchased and used the same yeast in the same packaging from the same store as you have.  And, like subfuscpersona, I've always kept it in a tightly sealed bag in the freezer.  It has always been reliable, even when long past its expiration date.


proth5's picture

and yet, my usage rate is so low on commercial yeast that I had a big batch expire - I mean really expire - dead.  So I don't buy the big blocks anymore.

So, even with careful storage, the stuff does have a "shelf life."

subfuscpersona's picture

...given your experience.

If stored as I (and others) suggest, commercial yeast (IDY and ADY) can be used with success for about 2 years after the expiration date on the package.

Would you agree with that?

proth5's picture

that mine was about 6 years old.  I swtiched from commercial to sourdough about 7 years ago.  Just guessing.  It's just that I had bought the line that yeast stays viable "almost forever" if you store it airtight in the freezer. Not so very true...

I do think it had been losing potency, because I was getting some frustrating bakes towards the end.  One day I decided to do a proof test and the poor little things didn't even dissolve right, let alone get foamy.

2 years sounds good.  I'm sure that mine lasted at least that long after the official expiration date.

But again, I don't think I'll ever push it that far again. I'm finding that for my current rate of use the jars of "Rapid Rise" or "Bread Machine" yeast are pretty economical.  The yeast companies are hopping on the bandwagon of "no knead bread" and issuing coupons.  Double those (as my favorite store does) and the yeast is pretty well priced.  Given the value of my time and effort, I'd rather err on the side of fresher yeast bought more often.

RiverWalker's picture

thank you for your patience and extensive spelling out of the issue of different types and which one I have.

up to this point I've been using bulk-bought Active Dry Yeast,  and I've used it everywhere along the spectrum from proofing it, to mixing it in with the flour, and had it work nearly perfectly, and the one or two times it didn't "go" did not appear consistent.

it is funny how forgiving some aspects of baking seems to be, and how different people can have better or worse luck while doing seemingly the same thing.

anyway, it looks like I got enough yeast of a good kind to last me a heck of a long time, for free.  awesome.