New research on dry yeast

[Wobbly74]

That sounds like really long lag times. My last lager got 2x 15g packs of 34/70 with no rehydration and I thought that took a long time at 21 hours to finish multiplying and start fermenting. This was at 13C. My straight pitched ales have started by about 8-10 hours. This is the graph from my last lager, a 1.050 Vienna Lager.

 

[Thomas Wood]

Yeh it's so strange. This one was even one of the Mangrove Jacks M44 US West Coast yeasts completely temperature controlled @ 19*C, but still an incredibly long lag time. (Ignore the gravity values, it's not completely calibrated yet).

 

[///]

When u say warm yeast, what temp ya talking?

Fermentation temp. We never used yeast that had been chilled.

 

[Wobbly74]

Maybe just try pitching commando next time and see if you get any difference.

 

[Dylo]

Might be this one.
If not and you want some more Yeast research PM me your e-mail address and I'll send a few, they are too big to post here.
Mark

I noticed that Fermentis have updated this doc too in this link: https://fermentis.com/tips-n-tricks/for-you-brewers/ I have one question for anyone that may be clever enough to offer suggestions...

Between the two documents they seem to have included one new point in the "rehydrating with wort" section. Now they specifically say the wort should be hopped. Any idea what advantage this would have over un-hopped?

 

[altone]

I noticed that Fermentis have updated this doc too in this link: https://fermentis.com/tips-n-tricks/for-you-brewers/ I have one question for anyone that may be clever enough to offer suggestions...

Between the two documents they seem to have included one new point in the "rehydrating with wort" section. Now they specifically say the wort should be hopped. Any idea what advantage this would have over un-hopped?

I thought the hop addition was to help prevent infection I have a little jar of old hops and add a couple of pellets to the starter - just in case.

 

[MHB]

I noticed that Fermentis have updated this doc too in this link: https://fermentis.com/tips-n-tricks/for-you-brewers/ I have one question for anyone that may be clever enough to offer suggestions...

Between the two documents they seem to have included one new point in the "rehydrating with wort" section. Now they specifically say the wort should be hopped. Any idea what advantage this would have over un-hopped?

Less bacteria is what comes to mind, hops are a bacteria killer.
Mark

 

[mfroes]

still can't find it at https://fermentis.com/news-from-fermentis/news-and-events/ or http://www.lallemandbrewing.com/news/

i see no changes on the fermentis and the lallemand websites or packages on the instructions of the yeast. in fact on both of them they say that can cause a few other things even. http://www.lallemandbrewing.com/products/brewing-yeast/ under the "Rehydration" tab says that can cause stuck fermentation, longer everything (lag, fermentation, diacetyl rest)... https://fermentis.com/tips-n-tricks/for-you-brewers/

 

[mfroes]

Contacted Brad smith and this was his answer about the aeration.

 

[Wobbly74]

Chris white is an expert on liquid yeast but doesn't deal in dry yeast. Not to say that he doesn't know a lot about it, but his recommendations are around the liquid yeasts he works with (just the context of the conversation). I've not had issues without hydrating dry yeast vs hydrating, but I always aerate for liquid yeast, either spun up from a pack or re-used...

 

[awfulknauful]

So what is the general consensus with the dry yeast?

 

[wide eyed and legless]

If using Fermentis dry yeast, Fermentis do not recommend aerating the wort , the ergosterol's (pretty much what cholesterol is for us) are incorporated in the dry yeast. I have also read that the cells are oxidated if there is such a word, or even if it can be done. I always rehydrate the dry yeast, reasons I have read for doing this is it is a shock for yeast to suddenly get dumped into the wort.
https://beerandbrewing.com/how-to-use-dry-yeast/

 

[goatchop41]

If using Fermentis dry yeast, Fermentis do not recommend aerating the wort , the ergosterol's (pretty much what cholesterol is for us) are incorporated in the dry yeast. I have also read that the cells are oxidated if there is such a word, or even if it can be done. I always rehydrate the dry yeast, reasons I have read for doing this is it is a shock for yeast to suddenly get dumped into the wort.
https://beerandbrewing.com/how-to-use-dry-yeast/

What about all of the pro breweries who rehydrate in wort, then do viability counts that are the same as water?

 

[wide eyed and legless]

Yeh what about them?

 

[awfulknauful]

So is it better to rehydrate yeast or not?

 

[wide eyed and legless]

So is it better to rehydrate yeast or not?

There has been many a discussion on here regarding that self same question. I have put out what I do, the best thing to do is research at what micro biologist and brewers say. Join Wiley online its free though sometimes you can't access all the info but you can access a lot.

 

[peteru]

So is it better to rehydrate yeast or not?

Simple enough to find out. Split your next batch in two and compare the results. No need to believe in science, just use empirical evidence to get the result that pleases you.

 

[goatchop41]

Simple enough to find out. Split your next batch in two and compare the results. No need to believe in science, just use empirical evidence to get the result that pleases you.

Yeah, sounds like a great idea...
Wait, no, you're saying to ignore what the manufacturer of the actual product has to say, and just perform a completely pointless, uncontrolled n=1 study...
...
...

 

[goatchop41]

So is it better to rehydrate yeast or not?

The reasonable and logical option would be that if the manufacturer recommends rehydrating, then rehydrate. If they don't, then don't.
We can rest assured that they know what they're talking about, since they make the stuff

 

[MHB]

Here is the latest US-05 spec sheet.
It doesn't mention wort aeration at all, I'm far from sure whether that means that they expect that
1/ any sensible brewer will have aerated their wort as a matter of course.
2/ It isn't necessary

They still recommend 50-80g/hl, at 23l, 50g/hl is 11.5g. No information is given on the effect of wort gravity so its pretty fair to assume that they are talking about "standard beer" (12oP and 25IBU (1.048)).

I suspect that if you aren't aerating you would want a bigger pitch rate to compensate, say up near the 80g/hl (~18.4g/23l). Good idea to pay very close attention to the recommended pitching temperatures to.
Mark

PS - This is really well worth reading Fermentis Tips and Tricks
M