Safale S-04: Accidental Stir

[nmendres]

Yesterday, I had 5 gallons of stout in my fermenter. I pitched Safale S-04 at 60 degrees F, and I accidently stirred the yeast into the wort before waiting for it to rehydrate (I'm afraid the yeast may have clumped). This morning I moved the fermenter to a warmer spot (68 degrees F), and shortly afterwards I saw bubbles escaping from the air lock (about one bubble every 1-2 seconds. Late this afternoon the air lock activity has stopped. Should I pitch another packet of Safale S-04 into the fermenter, not stir it, keep it at 68 degrees F, and wait to see what happens? Is this a good plan?

 

[boydster]

You'll be fine, let it ride, fermentation can take up to 72 hours to show visible signs of activity. When you moved the fermentor, you likely caused some CO2 to come out of solution, creating the bubbles you saw in the airlock.

Now, here's the thing. Next time you use this yeast, or any other dry yeast, you really should rehydrate it in warm water before adding it to the wort. Rehydrating is easy, and helps the yeast survive when it is introduced to your wort. It also helps reduce lag time because the yeast need to reproduce less before they get started munching on the sugars.

From Yeast pg 146:

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.

 

[nmendres]

Thanks Boydster.

I'm going to wait 72 hours. It's quiet right now. If there's no sign of fermentation, I'm going to try rehydrating a packet of Safale S-04 and re-pitch the wort. The wort has been sealed in the fermenter, so I'll give it a try.

 

[BigFloyd]

Thanks Boydster.

I'm going to wait 72 hours. It's quiet right now. If there's no sign of fermentation, I'm going to try rehydrating a packet of Safale S-04 and re-pitch the wort. The wort has been sealed in the fermenter, so I'll give it a try.

What's a "sign of fermentation" to you?

1) Airlock bubbles?

2) Krausen?

3) Drop in gravity?

Number one is rather unreliable since any little leak will let the CO2 out a way other than the airlock. Plenty of folks have reported zero airlock activity only to take a gravity reading 7 days after pitching and find out that it indeed fully fermented. Number two is pretty decent if you can keep an eye on it. The third one, via a hydro reading, is the only real way to know for sure.

You didn't hurt the S-04 in any way by stirring after you pitched, although next time you might want to rehydrate your dry yeast in warm tap water. Hold off on re-pitching until you can compare OG and current gravity.

Your pitch temp of 60*F was fine. 68*F ambient is a bit warm for S-04 during the first 4-5 days and can get you some off-flavors. It's fine for later in the ferment.

 

[nmendres]

Boydster thanks again for all of your sdvice.

I'm using a 6.5 gallon pale as a fermenter, so I really can't see whether krausen has peaked. Because of using a pale, I've been using air lock activity to judge what's happening and to justify opening the lid to take a specific gravity reading, not wanting to get nasty germs inside. I initially pitched yeast on Saturday, and I saw 4 hours of air lock activity on Monday morning. I convinced myself that I should open the fermenter and take a reading. There were definite signs that hrausen had happened, most of the foam has fallen back. My specific gravity reading this AM was 1.024 @ 70 degrees wort temp (1.025 corrected for temp). My original gravity was 1.054 @ 72 degrees, that's wort temp in the hydrometer vial (1.055 correct for temp). My recipe had OG = 1.069 and FG = 1.015. I'm not buying the recipe OG because the grain bill for this recipe is light malt extract. I've looked at similar recipes and they say OG closer to 1.058 to 1.050, so I'm in that range. My recipe says that fermentation should take 2 weeks (it's only been about 2.5 days), so I'm going to give it the full 2 weeks and see what happens. If you have more advice, please reply! I've only been homebrewing for about one year. Just trying all sorts of recipes, and boy do they behave differently.

 

[BigFloyd]

Boydster thanks again for all of your sdvice.

I'm using a 6.5 gallon pale as a fermenter, so I really can't see whether krausen has peaked. Because of using a pale, I've been using air lock activity to judge what's happening and to justify opening the lid to take a specific gravity reading, not wanting to get nasty germs inside. I initially pitched yeast on Saturday, and I saw 4 hours of air lock activity on Monday morning. I convinced myself that I should open the fermenter and take a reading. There were definite signs that hrausen had happened, most of the foam has fallen back. My specific gravity reading this AM was 1.024 @ 70 degrees wort temp (1.025 corrected for temp). My original gravity was 1.054 @ 72 degrees, that's wort temp in the hydrometer vial (1.055 correct for temp). My recipe had OG = 1.069 and FG = 1.015. I'm not buying the recipe OG because the grain bill for this recipe is light malt extract. I've looked at similar recipes and they say OG closer to 1.058 to 1.050, so I'm in that range. My recipe says that fermentation should take 2 weeks (it's only been about 2.5 days), so I'm going to give it the full 2 weeks and see what happens. If you have more advice, please reply! I've only been homebrewing for about one year. Just trying all sorts of recipes, and boy do they behave differently.

Good news. It sounds like the yeast are alive, well and doing their job. The best thing to do now is simply keep it cool, leave it alone and count the days.

Don't worry about the OG not being quite what the recipe says. It's really difficult to get a completely homogenous mix with extract so that any OG sample you might take would read the same as another.

 

[boydster]

Good! Just to piggyback with BigFloyd, the fact that it is an extract recipe means you are adding a known amount of sugar to a known amount of water, thus making it impossible to miss an OG unless you either mess up on your water volume or miss some of the extract. Top-off water added to the fermenter is really hard to mix completely with the wort so the recipe OG can usually be assumed to be correct.

 

[Kozwald]

I've used S-04 many times and don't usually re-hydrated. I sprinkle it on the wort, cover and let sit for about 20 minutes then stir the wort for 2 minutes. I usually see activity within 24 hours. I did re-hydrate once and didn't see any difference.

 

[boydster]

I've used S-04 many times and don't usually re-hydrated. I sprinkle it on the wort, cover and let sit for about 20 minutes then stir the wort for 2 minutes. I usually see activity within 24 hours. I did re-hydrate once and didn't see any difference.

Cool, glad it works for you, that is really what matters. People that count cells and write books about it find that up to 50% of the cells die due to the osmotic shock of being reconstituted in wort. People with very in-tune palates that judge beer at high levels find a greater presence of off-flavors like esters. Yeast microbiologists find a causation between what the cell-count folks and the beer-tasting folks notice. The great thing about home brewing, though, is that everyone gets to brew the beer they like in the manner they like.

And that's all I have to say about that.

 

[MorrisBrewingCo]

I personally do not re hydrate for two simple reasons.

1. The package clearly states dump directly in to fermenter with no rehydrating instructions.
2. Why add another variable to the pitching process?

When I read worries about if yeast is working usually they re hydrated. I pitch directly in and while transporting to fermenting spot it mixes it in. Sometimes I have clumps but always have 3 bubbles/second within 12-18 hours.

 

[wailingguitar]

Have experimented with the rehydrate/no rehydrate on the commercial level. Came to the conclusion that there was no appreciable difference in the final product. While it seems to be true that a significant portion of the cells get killed off in a no rehydrate situation, the cells that do survive use the others as "food", like a yeast energizer, net result; no difference.

Rather than sprinkle in and let it mix, I pitch the dry yeast into the fermenter than xfer wort on top of it. This results in a quick mix and a faster start to fermentation. I regularly have active ferment in 6 hours +/-

 

[boydster]

What you are describing is almost the same as pitching a smack pack with no starter... ~100 billion cells and some "nutrient". Regardless of the amount of nutrient in the wort, the yeast need to divide until there is a sufficient population to ferment the sugars. The excessive cell division that is a result of underpitching is primarily what causes the off flavors people talk about when they discuss flavors related to underpitching.

We are getting off-topic from what the OP was asking about, though.

 

[nmendres]

A final happy note. I checked the SG today and its was 1.016 @ 66 degrees. The recipe I'm following gives a predicted FG of 1.015. I'm going to wayt 2-3 days and take another reading. If my SG is 1.016 to 1.015, I'll probably get ready to bottle this batch. It looks like everything turned out fine.

 

[Black]

I personally do not re hydrate for two simple reasons.

1. The package clearly states dump directly in to fermenter with no rehydrating instructions.
2. Why add another variable to the pitching process?

When I read worries about if yeast is working usually they re hydrated. I pitch directly in and while transporting to fermenting spot it mixes it in. Sometimes I have clumps but always have 3 bubbles/second within 12-18 hours.

This.

I stir S-04 directly after pitching it dry from the pouch with great success. I actually brewed a 1.106 barleywine yesterday and pitched 2 packs of it. I just stirred the dry yeast in. No clumps. Fermentation is so active now that the cover unlocked and left foam out. Such a mess.

Cheers !

 

[Indian_villager]

....I toss my dry yeast straight into the fermenters without rehydration and they work every time!

 

[MorrisBrewingCo]

What you are describing is almost the same as pitching a smack pack with no starter

I advise you do more research because that statement is incorrect. Use Mr. Malty and a 1.055 OG 5.5 gallon batch requires 2.2 vials/smack packs however only 1 pack of 11.5 dry yeast.

 

[boydster]

I advise you do more research because that statement is incorrect. Use Mr. Malty and a 1.055 OG 5.5 gallon batch requires 2.2 vials/smack packs however only 1 pack of 11.5 dry yeast.

Right. Rehydrated though. Because not rehydrating kills half the cells. Mr. Malty himself has made that statement and said the calculator assumes you are pitching properly hydrated yeast. I urge you to do some research on the impact of pitching hydrated yeast vs dry. The is plenty of reading material and it all points to the vast majority of advice in this thread being bad.

 

[wailingguitar]

Right. Rehydrated though. Because not rehydrating kills half the cells. Mr. Malty himself has made that statement and said the calculator assumes you are pitching properly hydrated yeast. I urge you to do some research on the impact of pitching hydrated yeast vs dry. The is plenty of reading material and it all points to the vast majority of advice in this thread being bad.

Bad?

Have used dry, unrehdyrated commercially for years. In '99 I did a blind tasting with several industry colleagues, mostly brewers… side by side of rehydrated, unrehydrated and repitched … as well as ongoing repitched (up to 5th gen) vs unredydrated with the result being that there was no appreciable difference in the finished product. I consulted my Fermentis rep at the time and he verified that rehydration was not really necessary.

 

[boydster]

Yes. Bad. Example: Sean Terrill did cell counts using US-05, a Fermentis yeast, after hydrating in water and in wort. The result was that the viability of the yeast hydrated in wort was less than 50%. Now juxtapose that with what we know about pitching rate and how it affects a beer.

A rep told you that you didn't need to rehydrate? Like a sales rep...? What was your pitch rate? Maybe they wanted to sell you more yeast, so you use twice as much but still get the same # of viable cells to do the work?

Considering all of the science (and the majority of experience) clearly shows the benefits, I just don't understand the debate.

OP, glad you found some resolution, here's to good beer

 

[wailingguitar]

So you're telling me, in so many words, that I don't know what I am talking about... nor do my colleagues (most with either Davis or Seibel training)? As stated, we did the three way blind and ongoing repitch vs dry pitch with no notable difference in the finished product… Bad? yeah, right… You want to take the time to rehydrate? Knock yourself out!

Yes the rep was the 'sales rep', but he was also a brewer with a a degree in microbiology and the least pouchy 'salesman' I have dealt with in any industry… Typical pitch commercial pitch rates are 50g/bbl (basically a 500g brick for each 10bbls knock out), whether rehydrated or not.

 

[MorrisBrewingCo]

Bad?

Have used dry, unrehdyrated commercially for years. In '99 I did a blind tasting with several industry colleagues, mostly brewers… side by side of rehydrated, unrehydrated and repitched … as well as ongoing repitched (up to 5th gen) vs unredydrated with the result being that there was no appreciable difference in the finished product. I consulted my Fermentis rep at the time and he verified that rehydration was not really necessary.

Sounds legit to me and has worked for me flawlessly since changing back to dry yeast.

 

[boydster]

I'm simply telling you that there is a great deal of data in disagreement with what you are saying. It's great that your blind tasting got you the results that you are posting here, but other studies have found significant differences in the final product, and all studies where a cell count is done under a microscope after rehydrating in water vs wort show a large percentage of the yeast cells dying during reconstitution. This study is particularly interesting: http://seanterrill.com/2011/07/29/dry-yeast-viability-take-two/

As far as taking advice from microbiologists or people with training from reputable yeast gurus, Drs. Clayton Cone and Chris White both advocate rehydrating.

This professional brewer is pitching 2 rehydrated 500g bricks of S-04 into 15bbl: http://www.thebrewingnetwork.com/forum/viewtopic.php?f=&t=29788

Lallemand recommends pitching 50 grams per hectoliter, which is ~26.5 US gallons. Fermentis recommends pitching 50-80 grams per hectoliter of rehydrated yeast. Mr. Malty and YeastCalc both suggest you need around 1500 billion cells, or ~80 grams of rehydrated yeast for 1 bbl of 1.050 wort.

All signs point to your pitch rate being low to begin with. There are times when low pitch rates are used intentionally to make good beer (most beers with a strong yeast profile do this), so I'm not knocking you here, I am just pointing out that 50g/bbl is a low pitch rate and could certainly be contributing to the lack of difference in the final product in your study because dry-pitching the yeast also results in a lower pitch rate.

Of course you should do what works for you. Maybe I shouldn't have said your advice was bad. It is just different than my experiences and stands at odds with everything I've ever seen or heard from reputable sources. I'm offering advice that works for me and has substantial scientific data and real-world testing to back it up.

 

[MorrisBrewingCo]

Home brewers success rate with hydrating varies. I prefer not implementing that variable in my process and I get measurable great fermentation results. To each their own.

I still do not agree with is your statement of pitching one unhydrated 11.5 gram dry yeast is the same as pitching one smack pack or vial

What you are describing is almost the same as pitching a smack pack with no starter

 

[boydster]

When half the cells in the package die, you are left with ~75-100 billion cells, which is the same as a smack pack. Whether you agree with cell counts or not is up to you.

 

[MorrisBrewingCo]

But do they not have the other to feed them whereas a smack pack has 100 billion as it's limit? I am just saying it is not the exact same and I would argue that the differences points to the dry yeast being measurably more beneficial to the final product.

 

[boydster]

So are you saying that having 100 billion dead yeast cells in your wort is better nutrient than the packet of lab-prepared yeast nutrient that comes in the smack pack? And in your mind, does that somehow change the final number of cells, and thus, the number of cell divisions required to ferment a beer? Or is it just that the cell divisions somehow don't matter? I don't understand the logic.

 

[MorrisBrewingCo]

I am saying an unhydrated 11.5 gram packet of Safale US-05 ferments a 5.5 gallon Pale Ale batch around 1.055 OG better for me than a 100 billion cell Wyeast 1056 smack pack without a starter. I have no desire to play post tag with someone who obviously disagrees. You've presented your opinion and I have thrown it in with everything else I have read on this topic for my final consensus. To each their own.