Re-Hydrate v Not..

[Ducatiboy stu]

Better send them a link to this thread

 

[pcmfisher]

... or inability.

Check this out: "Wine-tasting: it's junk science"

http://www.theguardian.com/lifeandstyle/2013/jun/23/wine-tasting-junk-science-analysis?INTCMP=SRCH

Everyone knows wine tasting is a wank.

But this is beer, it's different, it's got hops in it.......... h34r:

 

[brewbienewbie]

I rehydrate my yeast because I figure my half-assed approach to temperature control probably stresses the little buggers enough as it is. It's really not much trouble now I have my technique down. I have a mug that I fill with boiling water for a few minutes, then empty and fill with tap water. I know from experience that this will end up between 30-35c after a minute, sprinkle yeasties on to that and they're away.

 

[Lord Raja Goomba I]

One thing to add or two.

If I have a notoriously slow starter, I'll rehydrate (US05 in colder applications, I've heard the same about BRY97). If it's a Notto or something, generally not, it'll be up and running so quickly. In this instance, it's about establishing the yeast's control over any other potential micro-organisms.

There are some styles I'll deliberately not rehydrate when it's a slow starter because I want the yeast to produce something that is easier to achieve happens with underpitching - Weissbiers and the phenols in that are the classic example.

A bit like the chill vs no chill - horses, courses of courses. And how much effort vs time vs effect do we put in our beers.

 

[Dengue]

I buy all the reasoining in the article that scientist slash posted, but still confused by the fermentis FAQ that explains you can hydrate in wort OR water....surely wort , unless very dilute, is detrimental...

 

[DJ_L3ThAL]

I buy all the reasoining in the article that scientist slash posted, but still confused by the fermentis FAQ that explains you can hydrate in wort OR water....surely wort , unless very dilute, is detrimental...

i think the half deaths occur more due to the temperature differential between the dry yeast and the medium it is pitched into. if youre hydrating your giving the yeast a better environment (temperature) to do so in rather than the lower temperature wort in the FV. Similarly if you pitched into 18C water youd still get half deaths. Have i got that correct?

 

[Dengue]

i think the half deaths occur more due to the temperature differential between the dry yeast and the medium it is pitched into. if youre hydrating your giving the yeast a better environment (temperature) to do so in rather than the lower temperature wort in the FV. Similarly if you pitched into 18C water youd still get half deaths. Have i got that correct?

Maybe thats Fermentis reasoning.

However the theory in slashes reference paper goes that the original awakeing , ie absorbtion of materials through the cell wall that are not regulated by the matabolic processes of the yeast is what kills them...

 

[slash22000]

Partially, DJ. The temperature is definitely a factor, but pitching dehydrated yeast into wort (at any temperature) kills yeast:

For the initial few minutes (perhaps seconds) of rehydration, the yeast cell wall cannot differentiate what passes through the wall. Toxic materials like sprays, hops, SO2 and sugars in high levels, that the yeast normally can selectively keep from passing through its cell wall rush right in and seriously damage the cells. The moment that the cell wall is properly reconstituted, the yeast can then regulate what goes in and out of the cell. That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be OK.

The idea is to rehydrate in water first so that the yeast can build up their cell walls as explained above, so when you pitch into your wort they are not poisoned by it.

 

[DJ_L3ThAL]

Ok cheers, would it bereasonable (sorry, slightly OT) to say recovering trub from a rehydrated yeast vs dry pitched yeast would have minimal difference if a sound washing process was followed to capture the good milky suspention, leaving as much trub behind as possible?

just spewing i didnt hydrate the us05 on my first all grain stovetop brew (as planning on havesting the us05 from the trub.

 

[Ducatiboy stu]

just spewing i didnt hydrate the us05 on my first all grain stovetop brew (as planning on havesting the us05 from the trub.

Dont stress....you will still have a good harvestable yeast cake. Just because you didnt rehydrate does not mean your beer and yeast cake will be shit.

 

[Dengue]

Partially, DJ. The temperature is definitely a factor, but pitching dehydrated yeast into wort (at any temperature) kills yeast:


The idea is to rehydrate in water first so that the yeast can build up their cell walls as explained above, so when you pitch into your wort they are not poisoned by it.

curious on your take on Fermentis instructions ?. Hydrate with wort OR water. No reference to the concentarion of such wort....

 

[slash22000]

I don't work for Fermentis and I can't give any legitimate answer as to why they would recommend hydrating with wort despite the fact it kills a lot of the yeast.

Danstar has an FAQ section that covers dry yeast rehydration:

Why is rehydrating the dry yeast before pitching important? Dry beer yeast needs to be reconstituted in a gentle way. During rehydration the cell membrane undergoes changes which can be lethal to yeast. In order to reconstitute the yeast as gently as possible (and minimize/avoid any damage) yeast producers developed specific rehydration procedures. Although most dry beer yeast will work if pitched directly into wort, it is recommended to follow the rehydration instructions to insure the optimum performance of the yeast.

Mangrove Jack also covers rehydration in their yeast booklet:

Although Mangrove Jack’s Craft Series Yeasts do not require pre-hydration, cleaner and more professional results may be produced if rehydrated before use.

 

[Dengue]

I don't work for Fermentis and I can't give any legitimate answer as to why they would recommend hydrating with wort despite the fact it kills a lot of the yeast.

Danstar has an FAQ section that covers dry yeast rehydration:


Mangrove Jack also covers rehydration in their yeast booklet:

yep and I am not saying you are wrong either.

unless, fermentis yeast is different somehow. ... nah

 

[Greg.L]

... or inability.

Check this out: "Wine-tasting: it's junk science"

http://www.theguardian.com/lifeandstyle/2013/jun/23/wine-tasting-junk-science-analysis?INTCMP=SRCH

It's a pity this sort of thing should get such acceptance on a beer forum. If you work in the wine industry you see that there is a lot of skill that goes into winemaking and wine evaluation. I know that I don't have the sensory evaluation skills to be a winemaker, you need a very experienced palate. It is when you meet and taste with experts you see they really aren't bullshitting, they can analyse wines with real expertise. If you think it is bullshit then I don't know why you think a forum like this would be any good. Not everyone agrees about every wine and it is easy to make it look like fakery if you pick and choose your data. These days on the internet everyone wants to think they are an expert, and rubbish the efforts of people who take the time to learn their craft properly.

 

[JDW81]

It's a pity this sort of thing should get such acceptance on a beer forum. If you work in the wine industry you see that there is a lot of skill that goes into winemaking and wine evaluation. I know that I don't have the sensory evaluation skills to be a winemaker, you need a very experienced palate. It is when you meet and taste with experts you see they really aren't bullshitting, they can analyse wines with real expertise. If you think it is bullshit then I don't know why you think a forum like this would be any good. Not everyone agrees about every wine and it is easy to make it look like fakery if you pick and choose your data. These days on the internet everyone wants to think they are an expert, and rubbish the efforts of people who take the time to learn their craft properly.

Totally agree. A good friend of mine is a winemaker and his nose and palate are a testament to the wines he creates. If wine tasting is fakery, then surely the same logic would apply to beer tasting/judging?

 

[manticle]

I think wine wankery might exist among some consumers who think an extra $5 makes the wine better but makers and industry professionals who undergo sensory evaluation training and have a lot of knowledge on the science and craft of winemaking are no different to their counterparts in brewing or indeed in the world of food. Likewise there are pretentious consumers of both of those.

I never understood why brewing needs to set itself up against wine (nor conversely why wine lovers need ever be snobby about beer). I imagine there are some pancetta makers out there who say nasty things about people who make proscuitto or Jamon.

 

[jotaigna]

Do you think that perhaps microbiologists have a perverse and twisted sense of humor, wrote the unashamedly ambiguous label in their products and now pose as brewers asking to rehydrate or not in forums worldwide?
I do

 

[Spiesy]

Please die thread.

 

[jyo]

Please die thread.

Maybe we could pitch the thread straight into some wort and half of it will die.

 

[Ducatiboy stu]

Please...we dont need secondry fermentation.