Fermentis dry yeast users

[chezhed]

The book "Yeast," by Chris White and Jamil Zainasheff reports that pitching dry yeast directly into wort reduces viability by around 50%. That's all I need to know to convince me to rehydrate my dry yeast.

Based on that, then just double the dry yeast pitched. What harm in that?

I was told by my former LBHS, whom I tremendously respect, that 90% of his customers always start out underpitching yeast with dry yeast....and he was a big advocate of Fermentis for the "average" to "experienced" homebrewer. rehydrating was only desired if you wanted to shorten the lag time.

The next step beyond dry to him was slanting your own He was not a fan of Wyeast and thought all White Labs required starters in his opinion probably because shipping to the deep South ain't real friendly to those vials...

I use Fermentis 95% of the time...I have rehydrated only a couple times. I always get good results. I'm experimenting now with a US-05 (2 packets) versus a starter San Diego Super Yeast (2 vials-2L) in the same batches under the same conditions....after 24 hours the SD showed activity, US-05 none...but 48 hours later they "look" the same.....I'm not taking any gravity readings for at least a week though.

So....based upon the convenience and track record, I'll continue with pitching dry US-05....two packs is still less money than one vial of White labs and I THINK i'm getting more cells.........

 

[peterj]

You can't vent build up that wasn't there already. that is to say,it's not like it was fermenting away like the next morning or something. There was no dissolved co2 to vent at that point. It filled the head space in that time why I don't know or care.

It doesn't have to fill the headspace with CO2 in order for the airlock to bubble. The headspace is already full of air, so there just has to be enough added gas of any kind to displace one bubbles worth of the air that is already filling the headspace.

It wasn't dissolved air,I don't shake like mad,I stir. the loose foam was about gone by the time I sealed it up.

The foam on top doesn't have anything to do with it. None of that is dissolved in the wort anyway. It doesn't matter if you shake or stir, the point of aerating is to dissolve oxygen from the air into your wort. And you said that you did this, so your wort has dissolved air in it.

Again, I'm not saying your airlock didn't bubble. I'm certain it did.

You keep swearing up and down that this event happened and you're not lying about it, but kombat has said multiple times that he believes you. The fact that it happened is not the issue here, it's why it happened. And I really can't figure out the reason you're suggesting. In the original post it seemed like you were implying that it started fermenting, but then in another post you said that's not what you were saying. So what do you think was happening?

You do not want the yeast to take a long time going slowly to build up the numbers need to ferment x amount of wort. Nasties could take over before the yeast can. don't you guys read on here? It's been taught for quite some time that you want to cut lag time so the yeast gets a foothold before something else in the minority takes over.

It is also desireable to help the yeast get a solid foothold before something else does.

It's true that you don't want yeast to have an excessively long lag time because this could allow other organisms to gain a foothold before the yeast can. But the lag time is when the yeast produce a lot of the esters and other flavors that you need in your beer. So if the lag time is way too short then the yeast don't produce the proper flavors.

 

[Wheatmeister]

Follow me with this.

10^0 = 1.
6 x 10^0 = 6.
A 6 with 0 zero's after it.
6 x 10^1 = 60.
A 6 with 1 zero after it.
So 6 x 10^9 would be a 6 with 9 zeros after it.
That's 6 billion.

I don't know how to make this any clearer.

Do you really believe a single packet contains 690 billion cells? Don't you see how that would be wildly overpitching, all the time?

Ppl have been pitching 05 and 04, non-rehydrated, for years with awesome results. I've used several packets for bigger gravity beers, but don't 90% of the time. Noone likes know-it-alls, Kombat.

 

[Yooper]

I've read from a couple sources who have invested significantly more time than myself that the actual number of cells contained within a gram of dry yeast is SIGNIFICANTLY higher than what's printed on the specification sheets. Read for yourself and draw your own conclusions:

http://seanterrill.com/2011/04/01/dry-yeast-viability/
http://www.mrmalty.com/calc/dry.html

Summary, with well handled, reasonably fresh dry yeast that is properly rehydrated you are looking close to 20 billion cells per dry gram (~230 billion cells per dry sachet). You can even decide to apply a 25% margin of error (for the benefit of the doubt) and you're still looking at about 173 billion cells (good enough for more moderate gravity 5 gallon batches).

Yes, those are the studies I know of, and where my 230 billion cells per sachet came from.

If you read the fermentis site, they say "at least 6^9" or something like that- meaning an unrefrigerated old package (but not expired) has "at least" that many. A fresh pack probably has much much more, as shown by the studies above.

I think the key words "at least" are being ignored in claiming the 69 billion cells per 11.5 gram package.

It's true that I haven't done a cell count, but if it was true that we were looking at a real figure of 69 billion cells per package, we'd all be responsible for grossly underpitching all of our beers and let's face it- we have not seen those results. Even if only anecdotal, I think we're onto something by claiming that our beers are not grossly underpitched, due to the results.

 

[rpe290]

I don't think I said 36 hour lag time but I can see how you would draw that conclusion. When I checked it at 36 hours, active bubbling was noted. I just pitched a cup of 3 week old us-05 slurry into a 1.040 ale at 65 degrees. 36 hours later, I see the airlock is going to just start bubbling. Mr Malty suggests pitch rate was close to double what was needed. You have no way of knowing but my fermentations are in morebeer pales which don't have much of a seal so fermentation has to be really active to see bubbling.

My point was more along 7 days to fully attenuate seems perfectly reasonable to me. When a slurry pitched high based on mr malty shows nearly the same progression as a sachet, I don't think I am under pitching with a sachet. However, I'm here to learn so if you see a hole here, please show me the flaw in my logic.

Sorry, misunderstood your 1st post...

I agree on the 7 days...

I will have to share that the last time I used (rehydrated) s05, it took 3 times as long to start as when I pitched active liquid (both around 1.050, same O2, similar pitching rates). But that might just be how they work for me...still made good beer.

 

[Hopper5000]

Yeah if you pitch without rehydrating aren't you just killing off the weaker cells

 

[rklinck]

Based on that, then just double the dry yeast pitched. What harm in that?

So....based upon the convenience and track record, I'll continue with pitching dry US-05....two packs is still less money than one vial of White labs and I THINK i'm getting more cells.........

But rehydrating is SOOOOO easy. The day before I brew, I boil water in a large pot and drop a mason jar in. I let the jar sit in the boiling water for about 10 minutes then put the top on it and screw it on. I let it cool on the counter overnight. Then you have sterilized water ready to rehydrate a pack of yeast on brew day.

 

[stpug]

But rehydrating is SOOOOO easy. The day before I brew, I boil water in a large pot and drop a mason jar in. I let the jar sit in the boiling water for about 10 minutes then put the top on it and screw it on. I let it cool on the counter overnight. Then you have sterilized water ready to rehydrate a pack of yeast on brew day.

I agree that it's easy to rehydrate yeast and my process is different.

Put 150 ml water in small saucepan, bring to boil (takes about 3 minutes), boil for 2-3 minutes with lid on, remove from heat, and place pot in cold water bath. I'll swap out the water in the water batch once or twice for fresh cold water. It only take about 5 minutes or less to be at ~85F, and remove from water bath. Sprinkle the dry yeast over the chilled water and cover for 10 minutes. Stir it up for a couple minutes, and cover for another 10 more minutes. At this point it's ready for pitching. Like most new processes, it sounds MUCH harder and more complicated than it really is.

 

[peterj]

But rehydrating is SOOOOO easy. The day before I brew, I boil water in a large pot and drop a mason jar in. I let the jar sit in the boiling water for about 10 minutes then put the top on it and screw it on. I let it cool on the counter overnight. Then you have sterilized water ready to rehydrate a pack of yeast on brew day.

It really is incredibly easy. All I do is put a half cup of water in a mason jar and microwave it until it boils. Usually takes about a minute. Then just let it cool (I'll put it in an ice bath if I'm in a hurry) to around 90F and sprinkle the yeast on top. After 15 minutes, mix it up, wait another 5-15 minutes, and pitch.

Also, I think Yooper has a point about the "at least" on the data sheets. The yeast companies would probably rather underestimate their product than overestimate.

And I also agree with the anecdotal evidence point. I would say most people who use dry yeast only pitch 1 pack for normal gravity beers and I never hear about off flavors from under pitching. I've even read head to head threads between something like US-05 and WLP001 with no mention of underpitching flavors from the US-05.

 

[nitton]

I'm simply saying that it is extremely unlikely that that bubbling was due to the yeast generating CO2 a mere 45 minutes after being dust. All the research indicates that it doesn't work that way. And we all know the many different reasons an airlock can burp. Active fermentation is just one cause, and 15 minutes after pitching, it is pretty far down the list of likely candidates.

What causes then the foaming when rehydrating yeast? (This is an actual question.)

I've started with boiled water (little or no gas in solution, presumably at least) at around 100F and dumped the whole packet in without stirring, and within 30 minutes I had tons of foaming and bubbles in the resulting yeast cream.

Additionally, if making pizza or bread dough and massively overpitching (say, a full packet of dry baking yeast in a single ball of dough or loaf) it starts rising within minutes. If you cut the dough, you see little pockets very, very quickly. This doesn't happen if you use less yeast.

Many quick bread doughs do this ("ready in an hour!") with active dry or instant yeast. They also taste terrible, but that's another matter.

 

[bethebrew]

It doesn't have to fill the headspace with CO2 in order for the airlock to bubble. The headspace is already full of air, so there just has to be enough added gas of any kind to displace one bubbles worth of the air that is already filling the headspace.



The foam on top doesn't have anything to do with it. None of that is dissolved in the wort anyway. It doesn't matter if you shake or stir, the point of aerating is to dissolve oxygen from the air into your wort. And you said that you did this, so your wort has dissolved air in it.



You keep swearing up and down that this event happened and you're not lying about it, but kombat has said multiple times that he believes you. The fact that it happened is not the issue here, it's why it happened. And I really can't figure out the reason you're suggesting. In the original post it seemed like you were implying that it started fermenting, but then in another post you said that's not what you were saying. So what do you think was happening?



It's true that you don't want yeast to have an excessively long lag time because this could allow other organisms to gain a foothold before the yeast can. But the lag time is when the yeast produce a lot of the esters and other flavors that you need in your beer. So if the lag time is way too short then the yeast don't produce the proper flavors.

Two thumbs up. All this BS about pitching "enough" yeast is just that. Overpitching helps the commercial brewer because it's FAST.

Otherwise, what possible difference could an extra few hours make in a wort where you have paid attention to sanitation??? Oh right, less and not more flavor. Sounds like a dumb idea.

Gee my big barleywine took all of 30 hours instead of 12 to get rocking with one pack of US-05 I tossed in. I am 18 hours behind schedule.

Whose schedule?

Safeale gave us a product easy to use, and effective. Adding a second step does nothing but add a second step. Oh but it's so easy to rehydrate blah blah blah. NO, it's easier NOT to rehydrate.

 

[stpug]

Safeale gave us a product easy to use, and effective. Adding a second step does nothing but add a second step. Oh but it's so easy to rehydrate blah blah blah. NO, it's easier NOT to rehydrate.

Then on your same logic, it's easier to just buy beer than make it
It's easier not to reply than to reply, BUT you took the time

 

[mattd2]

The number comes directly from the US-05 datasheet on Fermentis's website....

Has anyone considered to read the dosage instruction on the Fermentis spec sheet? 50-80 g/hl, 5 gallons ~ 20 litres => 10-16 grams per 5 gallon batch. Surpisingly close to a 11.5 gram packet.
But it also list that the * for calculation of bacterial as when pitching at 100g/hL (higher than their recomended rate) and this equates to 6*10^6 viable cells per ml - the recomended lower limit for >1.060 ales as per Wyeast website
Something is not right with what Fermentis is telling us.
For the record I pitch 1 packet into ~ 16 litres = 4.3 million cells / ml so neraly there

 

[HopZombie99]

I just finished bottling my last brew. 1.081 which finished up at 1.015. One dry packet of rehydrated US-05. No problems whatsoever. I'm not sure how many cells are in there, but its a fair few and enough to complete my 1080 beer.

 

[kombat]

Ppl have been pitching 05 and 04, non-rehydrated, for years with awesome results. I've used several packets for bigger gravity beers, but don't 90% of the time. Noone likes know-it-alls, Kombat.

I don't mean to come off as a know-it-all, I'm merely trying to make sure I'm pitching the proper amount of yeast. "Conventional wisdom" appears at odds with the manufacturer's own specifications, and I'm trying to resolve the discrepancy.

It appears that 6 billion cells/g is the guaranteed minimum cell density, rather than the expected density. That is, a properly rehydrated packet of US-05 will have no less than 69 billion cells, but (apparently) often/usually up to 200 billion.

 

[kombat]

Otherwise, what possible difference could an extra few hours make in a wort where you have paid attention to sanitation???

Stressed yeast, and corresponding off-flavours.

Adding a second step does nothing but add a second step.

No, it doubles the yeast's viability, getting you closer to the recommended cell count for a given batch size.

The guidelines exist for a reason, and it's not just to sell more yeast or trick homebrewers into wasting time rehydrating yeast unnecessarily.

 

[Ster]

Why do you boil your rehydrating water?

I top off partial boils with straight unboiled tap water, so why boil the starter?

I do, however, spray the water pitcher with starsan.

 

[stpug]

I boil my rehydrating water as a safeguard against organisms I don't want. It's just a precaution. I have rehydrated with filtered tap water once or twice with no bad effects but I wouldn't ever suggest to someone else to do that simply because I don't want to be the reason they introduced 'badness' into their brew.

I also used to top off with straight filtered tap water and created good beer. Plus, the water contained dissolved oxygen so I didn't have to worry about aeration quite as anally as I do with full batch boils.

It's all just risk reduction I guess. If you can reduce risk of infection by 3-4% a few times then the sum is a reduction of risk by 3-4 X a few (10-20% risk reduction; maybe more, maybe less).

Recently, I rehydrated a couple mangrove jack yeasts. Those beers still had significant lag times (18 and 32 hours). I assume I helped my case in not introducing potential bad organisms by using boiled water. Another thought that goes through my mind is: "what if my rehydrating CAUSED the long lag phase?" Another thought is: "What if the lag phase would have been LONGER if I had not rehydrated?" And lastly: "Can Mangrove Jack yeast really be providing 200b yeast in their 10g sachet if the lag phases are lasting this long?" Unfortunately, I can't answer any of those questions conclusively. Basically, you find a formula that works for you and your system and roll with in until change is required.

 

[KepowOb]

So while all this was going on, I decided to contact Fermentis and ask them about it.

As some people mentioned, the amount listed in their documentation is a minimum, normally there is more. Here is exactly what they told me:

"Our documentation is giving our guaranty. The average contain of a sachet of US05 at packaging is 150 billion of viable cells."

Sorry to revive a bit of an old thread, but I figured it's always nice to have the official answer.

 

[stpug]

Thanks for sharing KepowOb. You didn't happen to ask them about what happens to those cells when pitched dry versus rehydrated did you? I assume their response is 150b/sachet prior to using them. Everything we've heard from scientific-oriented folks with sufficient equipment indicates some kind of loss when they're actually used. It seems the loss is greater when they're pitched dry but there appears to be loss even when rehydrated. Thanks again!

 

[boydster]

You can get 100% viability if you properly rehydrate a packet of dry yeast at optimal rehydration temperature (95*-105*F). Fact.

 

[KepowOb]

Sorry stpug, I didn't ask about anything else. It took them awhile to get back, but I'll shoot them another email and see what they say, but it might be awhile before they get back to me.

You can get 100% viability if you properly rehydrate a packet of dry yeast at optimal rehydration temperature (95*-105*F). Fact.

Not that I don't believe you, but I tend to take things posted on the internet that state something as a fact (without anything backing to back it up) with a grain of salt. Again, I don't see why rehydrating it properly would hurt the viability much, but do you have any links that back this up? Also, you say 95-105F, but Fermentis says to rehydrate at 80F (+/- 6*)...

 

[boydster]

Not that I don't believe you, but I tend to take things posted on the internet that state something as a fact (without anything backing to back it up) with a grain of salt. Again, I don't see why rehydrating it properly would hurt the viability much, but do you have any links that back this up? Also, you say 95-105F, but Fermentis says to rehydrate at 80F (+/- 6*)...

That is a great rule to live by I have the page earmarked in my book, will post the full quote and page number for you as soon as I can get the sleeping baby out of my arms (hopefully without waking up...)

 

[stpug]

Two sources for experimentation on rehydrating dry yeast followed by cell counts are:
http://seanterrill.com/2011/04/01/dry-yeast-viability/
http://woodlandbrew.blogspot.com/2013/02/rehydrating-safbrew-yeast.html

In both of the sources, neither shows a rehydrated viability greater than (max) ~90% at varying temperatures. However, neither experimented (or published) data points using temperatures as high as what boyd mentions either.

 

[boydster]

Long quote here, but the information is invaluable so I wanted to get it all in.

Yeast, pgs 146-147:

Every yeast strain has its own optimum rehydration process, but the basic procedure is as follows:
1. Warm the dry yeast to room temperature.
2. In a sanitized container, prepare an amount of sterile tap water at 105*F (41*C) equal to 10 times the weight of the yeast (10 ml/g of yeast).
3. Sprinkle the dry yeast on top of the water, trying to avoid setting up large, dry clumps. Let it sit for 15 minutes, then gently stir.
4. Once the yeast has reconstituted, gentle stir once again to form a cream, and let sit for another 5 minutes.
5. Carefully and slowly, adjust the temperature of the yeast to within 15*F (8*C) of the wort temperature.
6. Pitch the resultant cream into the fermentation vessel, ideally as soon as possible.

Controlling temperature is the most important part of the process. Rehydration generally ranges from 95 to 105* F (35 to 41* C) although some manufacturers suggest a lower temperature range. The ideal temperature for each dry yeast product can vary, and you should strive to find out from the manufacturer what temperature is optimal for their product. Do not attempt to rehydrate yeast in cold water. Warmth is critical to the cell during the first moments of reconstituting its fragile cell membrane. Lower temperatures result in more cell material leaching out of the cell during rehydration, which permanently damages the cell. At the optimal rehydration temperature, it is possible to recover 100 percent of the cells. Too cold a temperature can result in the death of more than 50 percent of the population. You should measure the temperature of the rehydration vessel just before adding the yeast. The temperature of the water can drop significantly if the vessel is colder than the water.

Most filtered tap water works well for rehydration. Ideally, the mineral content should range from 250 to 500 parts per million hardness. During the first few moments of rehydration, the cell cannot regulate what passes through the membrane. High levels of sugars, nutrients, hop acids, or other compounds can enter freely and damage the cells. This is why adding dry yeast directly to wort results in such a high percentage of dead ad damaged cells.

They also say that it is OK, after the yeast has been reconstituted, to use your chilled wort in small increments to bring the temperature of the yeast down close to pitching temperature - add small amount of wort, stir, wait a few minutes, repeat. You just want to use small amounts because dropping the temperature too quickly causes heat shock for the yeasties.

 

[boydster]

In both of the sources, neither shows a rehydrated viability greater than (max) ~90% at varying temperatures. However, neither experimented (or published) data points using temperatures as high as what boyd mentions either.

I can't speak for those that carried out the experiments, but viability does drop quickly as the rehydration temperature is lowered.

 

[stpug]

Thanks boyd!! Good read and could explain (at least mostly) why those referenced experiments yielded lower viability rates. I am brewing later on today and pitching a dry sachet of yeast. I intend on following the method described in your quote from the book, Yeast.

Very interesting information on cellular death by simply colder water temperatures (up to 50%). Compound that with using cold wort as your rehydrating medium and the proposition of losing at least 50% of your yeast is very real.

Great information on yeast going around lately. Hopefully this will lead to generally better guidelines on yeast handling, pitching amounts, and the variability that exists between sources of yeast. At this point, we need to be considering our form of yeast (dry, commercial liquid, repitch liquid), type of beer (ester dominant, ester neutral), strain of yeast (goes along with esters), rehydration method if using dry, etc... in order to have a more accurate representation of what we're pitching into our beers and how we can expect it to perform. Granted, we'll never really know without turning our homes into a White Labs but it's a start I suppose. It begs the question, is it time for our trusty pitching calculators to be either A) more customizable, or B) less of such a concrete source of pitching rates. I'd love to see something like a 'simple' interface just like we currently have, and an 'advanced' interface for those willing to play with variables (yeast form, hydrated, strain, level of esters wanted, etc).

 

[stpug]

Just got done following the process outlined in Yeast (posted above by boyd). This is the third Mangrove Jack yeast I rehydrate. The first two were according to manufacturers instructions and temperatures. This one was according to the process above. I can definitely say that this particular time (105F water) was much more lively looking than the previous two (85F), and looked more creamy and bubbly. This was closer to my experience with Nottingham albeit less creamy and bubbly, but much more so than most other rehydrating attempts.

Next I'll have to see how the lag time differs from the other two sachets of MJ yeast because those took 18 and 32 hours (1.047 and 1.058, respectively). The former I'm okay with, that latter felt longer than I'd generally want.

Cheers! Thanks again for the share!

 

[boydster]

Here's to a healthy fermentation!

 

[KepowOb]

Looking forward to hearing how it goes. It's great having so much discussion about dry yeast, since normally gets so little attention.