Yeast bought in snaplock bags

[brewermp]

Hi all,

When I first started brewing around 4-5 months ago I bought a small amount of yeast from my LHBS store it was titled wb06. It was provided in a small snaplock bag and stored in the fridge. I have two questions

1. Would it still be good?
2. Would rehydrating give me a better understanding if it was still viable?

Thanks in advance

 

[QldKev]

If it was put in a snaplock bag I would not use it, even after a day or so. I would never pay for it stored that way.

 

[brewermp]

Yeah I bought it in snap lock bags, never opened though. Looking back I see how stupid the decisions was of purchasing in snap lock instead of vacuum sealed bags. Hind sight is beautiful ey haha

 

[Ducatiboy stu]

Rehydrate it. I would bet that its OK

 

[brewermp]

Yeah I'm gonna give it a crack.. I've no chilled so am safe to get another packet of something else if need be. I will post photos here.

 

[QldKev]

I would not be worried if it will fire up, I'd bet it will. I'm more worried about what other funkies are in for the ride. Those bags are not impervious to air.

 

[Ducatiboy stu]

Help, help...the sky is falling.....

 

[QldKev]

Help, help...the sky is falling.....

Gee, that's a useful comment.

Maybe you should let the yeast companies know they are wasting their money nitrogen flushing and using their foil bags, when they could just pour the yeast into a ziplock bag.

I'm not guaranteeing the yeast will have an infection, I just would not risk it.

 

[Ducatiboy stu]

Best be using irradiated sterile water with the yeast then

 

[elcarter]

Slow day so I was curios if a microbe can get though a zip lock bag to spoil / mutate yeast. Given it was packaged in a sterile environment, not punctured ect.

What are zip loc bags made of?

LDPE

http://en.wikipedia.org/wiki/Polyethylene

Low-density polyethylene (LDPE)[SIZE=small][edit][/SIZE]
LDPE is defined by a density range of 0.910–0.940 g/cm3. LDPE has a high degree of short and long chain branching, which means that the chains do not pack into thecrystal structure as well. It has, therefore, less strong intermolecular forces as the instantaneous-dipole induced-dipole attraction is less. This results in a lower tensile strength and increased ductility. LDPE is created by free radical polymerization. The high degree of branching with long chains gives molten LDPE unique and desirable flow properties. LDPE is used for both rigid containers and plastic film applications such as plastic bags and film wrap. In 2009 the global LDPE market had a volume of about US$22.2 billion (€15.9 billion).[7]

What's the permeation size of LDPE polyethylene?

http://www.goodfellow.com/E/Polyethylene-Low-Density.html

Property Value
Permeability to Carbon Dioxide @25C x10-13 cm3. cm cm-2 s-1 Pa-1 10
Permeability to Hydrogen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 8
Permeability to Nitrogen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 0.7
Permeability to Oxygen @25C x10-13 cm3. cm cm-2 s-1 Pa-1 2
Permeability to Water @25C x10-13 cm3. cm cm-2 s-1 Pa-1 70
Permeability to Water @38C x10-13 cm3. cm cm-2 s-1 Pa-1 120

https://www.youtube.com/watch?v=wO1yq6YTJDI

Whats the desity of LDPE and is yeast bigger or smaller?

Density of LDPE 0.92 g/cm3

Density of dry celled walls of Saccharomyces cerevisiae 1.180 g/cm3

From this quick search of un verified or checked internet warrior knowledge ( no idea on half the stuff I just read). I've come to the (no doubt incorrect) conclusion Zip lock bags do let compounds though that may effect your yeast health.

However they may not let other forms of Saccharomyces though?

I'm not sure (but suspect) there's other (microbes / pathogens / yeast killing / mutating, compounds) that may be smaller but I think it's time for you all to find some holes in this shit I've just written and put the zip loc bag yeast thing to rest

 

[jyo]

Chances are, it'd be useable. Many of us have stored yeast in non-sterile environments like PET bottles without perceivable infections.

But, probably better to use it for a pizza base.

 

[Camo6]

I'd hate to waste a batch of beer that takes me four weeks to produce because of a $5 bag of unknown yeast. But that's just me.
You could always grow it in a starter, decant a bit and taste, but hardly worth the effort.
I wouldn't be so much worried about the integrity of the bag but how it was handled before going in to it.

 

[manticle]

Best be using irradiated sterile water with the yeast then

Boiling water is an easy, safe bet.
Use toilet water if it suits you - no system is perfect but don't shit on others for whatever precautions they want to use.
It's evident from some of your yeast threads that yeast handling is not something you value highly. Fair enough if it works for you.
I have 3 kegs of shit beer I connect with careless top cropping from recent attempts to use up ingredients and that 15 hours of brewing + ferment time and ingredients cost is all now wasted.
I'm returning to my anal wanker ways so I can drink beer rather than tip beer.

 

[DJ_L3ThAL]

I must be an anal wanker too...

 

[Black Devil Dog]

I've got 2 fermenters full of beer that taste like someone has shat in them. I skimped on the yeast handling/preparation and now I regret it.

 

[Ducatiboy stu]

Boiling water is an easy, safe bet.

Not according to some.

 

[elcarter]

Geeze I researched all that science "stuff" and your still intent on ear bashing each other.

I think we have two polarized views on suitability of yeast packaging material. Best bet to aim somewhere in the middle.

I'm not sure that's with zip lock bags but PET bottles have been used with good results. Just make sure it's been developed with MXD6 catalyst. ( just being a dick now)

I can see people now walking around with 600ml 'coopers' plastic PET bottles of dry yeast. Should develop a flat bottom for the stir bar. Shake and bake starters..... I'm so on to something here.

Since beer is especial sensitive to oxygen and has to be protected against loss of CO2, 5% or 8% wt. MXD6 with catalyst should be used for beer

http://www.ilsi.org/Europe/Documents/131.pdf

 

[Ducatiboy stu]

Boiling water is an easy, safe bet.
Use toilet water if it suits you - no system is perfect but don't shit on others for whatever precautions they want to use.
It's evident from some of your yeast threads that yeast handling is not something you value highly. Fair enough if it works for you.
I have 3 kegs of shit beer I connect with careless top cropping from recent attempts to use up ingredients and that 15 hours of brewing + ferment time and ingredients cost is all now wasted.
I'm returning to my anal wanker ways so I can drink beer rather than tip beer.

Topp cropping is always has more chances of infection than a dried yeast....I am supprised you dont already know this

 

[DU99]

:icon_offtopic: My question is people can buy bulk packets of yeast.how does one open the packet and store it.

 

[Ducatiboy stu]

:icon_offtopic: My question is people can buy bulk packets of yeast.how does one open the packet and store it.

I put mine into a clean glass jar....or god forbid...a ziplock bag.... :super: