Can anybody explain the difference between ‘instant’ and ‘rapid-rise’ yeast? I’ve Googled yeast and not been able to find a satisfactory reply. Recently I had a problem with minimal to no oven spring in my bread. I had been using rapid-rise yeast I bought at Sam’s Club in a two-pound package and had stored in the freezer. My hunch was that the yeast was old and so I changed to Fleischman’s regular granulated yeast, the kind that requires proofing in liquid, which corrected the oven-spring problem. My supermarket sells rapid-rise yeast and never seems to have instant, which is recommended in Rose’s Bread Bible. Are ‘instant’ and ‘rapid-rise’ the same or is there a real difference? I’ve read that ‘rapid-rise’ is good for only one rise, but that doesn’t seem to make sense, given that yeast feeds on the starch in flour and continues to grow during the fermentation process. Does anybody have an answer to this. Many thanks!
In case this topic has been covered already, I’m a new member!
Can anybody explain the difference between ‘instant’ and ‘rapid-rise’ yeast? I’ve Googled yeast and not been able to find a satisfactory reply.
Both Fleischmann’s and Red Star say that Instant Yeast and Fast-rising yeast are the same. Some people, not the manufacturers, claim that Fast-Rising yeast is Instant Yeast with more nutrients added to ensure a faster rise, but I haven’t seen any evidence of this view. Instant yeast, when using the same quantities as Active Dry, will certainly produce a faster rise.
I’ve read that ‘rapid-rise’ is good for only one rise, but that doesn’t seem to make sense
Yeah, that’s silly. I view that as more of a marketing gimmick; the typical casual baker views a fast rise or a skipped bulk fermentation step as an advantage, rather than the defect that it is.
I use Instant yeast exclusively and have generated three, sometimes four, rises out of it.
Thanks for the quick response! I may give the Fleischmann rapid-rise a try and see how it goes, since the company itself says there’s no difference between it and instant. I do note, however, that even the regular active dry yeast I’ve been using works really fast! But I would like the option of adding yeast to the dry ingredients and not having to mess around with the proofing stage.
That site contains claims at odds with the manufacturers, namely the existence of additives that make “rapid rise” rise faster. Not to say they’re wrong, but there’s no reason to think that the author has access to any more accurate information than we do.
But hey, why argue about how many teeth the horse has when we can go count them? The ingredient label of my Fleischmann’s Bread Machine yeast contains only yeast, sorbitan monostearate, and ascorbic acid. If someone has a packet of their “Rapid Rise”, it would be interesting to know if there are any other ingredients listed on the label. (BTW, it seems that their “Bread Machine” yeast only comes in a jar, whereas the “Rapid Rise” only comes in packets.)
It is confusing. The Red Star site claims the rapid rise is 50% faster and not suitable for extended rise or refrigerated recipes. Seems at odds with it being the same product. I know that vitamin C is good for yeast though I wouldn’t think that would explain 50%.
It is confusing. The Red Star site claims the rapid rise is 50% faster and not suitable for extended rise or refrigerated recipes.
I really suspect they’re merely spinning the natural fact that you need less instant yeast than active dry. If you use the same quantity, you’ll probably get close to a 50% faster rise, particularly if you bloom it in warm water. And when you have a fast rising dough, it is indeed a problem if you want to refrigerate it, because you can’t get it cool fast enough to slow down all that yeast. Been there, done that. I really don’t like their “not recommended”, er, recommendation of instant yeast for refrigerated doughs. Why not, for Pete’s sake? Personally, I used instant yeast for refrigerated doughs all the time, although I’ve never bought Red Star, as far as I can recall.
Especially in light of this reference from ‘Essentials of Food Science’
Table 15.3 Forms of Yeast
Active dry yeast (ADY)
1 teaspoon ADY = 1 cake of compressed yeast (CY)
Contains approximately 2–1/4 teaspoons per envelope
Leavens 6–8 cups of flour Has a longer shelf life than CY
Less moisture than CY
Cake or compressed yeast (CY)
Moist yeast with starch filler
Short shelf life—must be refrigerated or yeast cells die
Quick rising dry yeast
Is rapidly rehydrated Raises a mixture rapidly
Is formed by protoplast fusion of cells
but then there is this from ‘The Science of Cooking’
Types of yeast There are three types of yeast you may see on sale. Fresh yeast, which you can buy from some bakers and health food shops, is really a block of compressed yeast (usually containing a little corn flour to help keep it dry) . The overall water conte nt in fresh yeast is around 70%, with most of the water being inside the yeast cells. This form of yeast must be stored in the refrigerator, otherwise it will quickly spoil. As soon as sugar is added to the block of yeast, it will almost immediately begin fermenting the sugar and will produce some water so turning the whole block into a bubbling liquid. This mixture can then be added to any re- cipe requiring yeast.
Dried,oractivedriedyeast,isaproductthatisnotoftenseentheseday .Inthisformmost of the water has been removed from the yeast cells, thus preventing them from carrying out any fermentation. On the addition of warm water to granules of dried yeast, many of the yeast cells are able to absorb enough water to come back to life and begin fermentation. However, a good proportion of the cells die completely in the drying proce s and are never activated again. To use this form of yeast you have first to add warm water to the dried granules and then add some sugar and leave until a vigorous fermentation has started be- fore adding to the dough.
The third type of yeast is a recent innovation. As microbiology has improved, so better methods of drying yeast have been discovered, so that today it is possible to dry yeast cells to a moisture content of around 20% and then encapsulate them in a special emulsion, which contains nutrients for the yeast cells when they are re-hydrated. This form of yeast known usually as “easy bake yeast” needs no special treatment to activate and can simply be added along with all the other dry ingredients. Certainly, this form of yeast is very easy to use and more or less guarantees success.
or this from ‘The Science of Bakery Products’
18.104.22.168 Dried Yeasts. The traditional form of dried yeast is known as active dry yeast (ADY). This product normally only had 75–80% of the gassing ability of a compressed yeast on an equivalent basis. ADY has to be rehydrated with water at around blood heat before it can be used.
More modern forms of dried yeast are now available, known as instant active dried yeast (IADY) and protected active dried yeast (PADY). These types of yeast can be mixed directly into dry ingredients, making them more effective at gas production than ADY.
Because the activity of dried yeast is reduced by exposure to oxygen, IADY is supplied vacuum packed or with an inert gas in the head space. PADY, which has the yeast encapsulated in fat, relies on an anti-oxidant for stability. PADY is essential for domestic bread machines.
Basically, you can think of active dry and instant as the same thing, except that with active dry about 25% of the yeast is dead, and it is recommended to hydrate the yeast before adding to a dough. To convert from one to the other you just adjust the quantity to make up for the different activity levels.
Bread machine, instant, instant dry and rapid-rise all can be used in the same manner and measure, they are all forms of instant yeast. Additives like vitamin C (ascorbic acid) are intended to strengthen the gluten.
Feel free to use less yeast than a recipe calls for, slower rise = more flavor. If you want to retard loaves or go through multiple rises, you may find that you need to cut way back on the yeast (which will slow everything down) in order for the amylase enzymes in the flour to produce enough sugar to feed the yeast. Too much yeast or too much fermentation can use up all the sugar in a dough and make it taste flat/spent.
Do you want to tell us more about the bread that didn’t rise? It may just be that the quantity of instant yeast needed to be reduced to make the activity level come out equal to that of active dry yeast. Were the rising temperatures different for the two loaves?
Interesting that none of those sources mention the granules of instant yeast being smaller. Is it true? I found this site called “Dr. Yeast”, where the author claims to have spent “22 years experience in the Yeast Biotechnology field, concentrating on R&D projects.” He writes:
The manufacturing process for instant active dry yeast is similar to that for active dry yeast with a few exceptions. Prior to being extruded, the press cake may be plasticized with an emulsifier as an aid to yeast rehydration in the dough. The yeast mass is extruded through smaller perforated plates or screens than those used for active dry yeast, cut into small oblong, thread like particles and dried in a fluid bed dryer. The combination of strain chosen for instant yeast, the growth conditions, the drying method, and the addition of emulsifiers tend to place instant yeast intermediate between compressed and active dry yeast relative to activity in lean dough. Good instant active dry yeast has lower gassing power than compressed yeast and more than active dry yeast. Instant active dry yeast is available to commercial bakers in 500 g packets. Instant active dry yeast has 97.0% solids and 3.0% moisture content. The shelf life of instant yeast stored at room temperature is approximately 2 years from the production date. It is recommended to blend it completely with the flour before adding water.
As Charles has observed the granules of the instant are smaller. I would surmise that the market for the instant is perceived to be bread machines and home baking. To achieve the proper mixing without the rehydration step of active dry you would want smaller grains.
To return to the original issue. Several of the sources I read made the claim that instant yeast should not be used when the dough will be chilled or frozen because the instant is less hardy than other yeast. In addition once exposed to oxygen the instant has a much shorter shelf life than active dry (in the neighborhood of one week). These claims would explain why Mack had difficulty with his yeast stored in the freezer.
Many thanks to all of you who have responded to my yeast question. By the way, it was the yeast that I stored in the freezer, not the dough. My hunch was that yeast in such a large quantity put out for sale at a place like Sam’s might be akin to books put out on the remainder table at the book store (Remember those good old days?!)—oldies but cheapies! Thanks again for all of your help!
In the supermarket today, I looked at the ingredients on the various yeast products. What I found is
1) Fleischmann’s Rapid rise contains the same ingredients their Bread Machine Yeast: yeast, sorbitan monostearate, and ascorbic acid.
2) Active Dry is missing “ascorbic acid”.
3) The store brand Bread Machine yeast has the same ingredients as Fleischmann’s.
Ascorbic acid (Vitamin C) is often touted as a booster for yeast activity, and it suggests that Instant is “Rapid Rise”, too. Sorbitan monostearate is an emulsifying agent and is contained in both of Fleischmann’s products, but supposedly, Red Star does not include it in the Active Dry product, according to their website (my store didn’t carry it). I’ve read that some people are allergic to the additive, since it’s made from corn.
(Note: While ascorbic acid is used as a dough conditioner, I’m skeptical that this is why it’s included in yeast….it would be presumptuous for the manufacturer to assume I wanted a dough conditioner. Ascorbic acid’s inclusion in some yeast is explained variously as 1) a substance that will increase yeast activity, or 2) a preservative.)
Ironically, the Red Star website FAQ says that Instant works due to smaller particle size, which contradicts the document Gene posted (from Red Star) which claimed the faster rise was due to different strains of yeast. Argh!
And which ‘instant’ yeast are you storing in the freezer? I think part of the problem is that manufacturers can call whatever they want ‘instant’ ‘rapid’ etc. Probably the references I read were talking about rehydrated yeast (can’t remember clearly). I suspect some makers simply run their regular yeast through smaller dies/mills add some dough ‘improver’ and call it ‘instant’. I am also skeptical of calling these extra ingredients dough conditioners. I don’t think there is enough in 2 tsp to make much impact on a batch of dough. Probably the ascorbic is simply a preservative and the sorbitan allows the yeast to disperse better.