Dried yeast packets - what to do with em

[ryan]

And I just smile and nod... just smile and nod

[SpillsMostOfIt]

I sometimes get confused as to who runs this site?!!

Umm that'd be Chris (capital C)

Me (lower case c + .), I'm a troll.

SpillsMostOfIt is the resident 24-7 comedian.

I prefer 'Comedian in Residence'. Apart from anything else, I've already had the cards printed.

[ryan]

Wonder what Chris with a capital C has got printed on his?

[ryan]

That was just an idle thought that meandered through my mind as I drank my morning coffee. Not an intentional thought.
Just smiling and nodding...

[chris.]

BSA.

Can I stop smiling & nodding now?

[KEG]

i just urban-dictionary'd "BSA". the second definition is.. well, colourful.

BSA = burning swamp ass - a condition common in Kansas City, Missouri, whereby a person drinks copious amounts of Boulevard beer (which has an unknown secret ass-leak ingredient) and eats fiery hot wings from The Peanut. The next day after taking a healthy dump, burning swamp ass ensues and said person has to wipe their fiery hole on 15 minutes intervals for 2 hours after.

The beer and wings were great, Rob, but I've got BSA so bad it's making me sweat and tremble. Can you smell it, or should I show you the tracks on my skivvies.

[chris.]

Is a lot more colourful than a "Bachelor of Science and Arts"

[ryan]

there`s too many chris`s on here. I can`t figure it.

[KEG]

Is a lot more colourful than a "Bachelor of Science and Arts"

i'd go as far as saying it's more colourful than a "bullshit artist" too...

[lethaldog]

Smiling and nodding

Seems like a growing trend so thought i would jump on the band wagon

[ryan]

it`s like those clown games you see at the show, where you have to roll the table tennis ball into their gob......smiling and nodding. Not as easy as it looks.

[Trough Lolly]

Now I`m all mixed up again . Do you mean why we shouldn`t smile and nod? Or why we shouldn`t throw old packets of yeast into the boil?
I`ll stop smiling and nodding till there`s a clarification, just to be on the safe side.

Yes, toss the yeast in the boil when there's 10mins to go...It's fine, the cell walls will rupture and provide nutrients for the pitched yeast to use during the adaptive phase (first 16 or so hours after pitching). I don't toss more than one sachet worth of yeast in a boil however...

Cheers,
TL

[chris.]

Now I`m all mixed up again . Do you mean why we shouldn`t smile and nod? Or why we shouldn`t throw old packets of yeast into the boil?
I`ll stop smiling and nodding till there`s a clarification, just to be on the safe side.

Yes, toss the yeast in the boil when there's 10mins to go...It's fine, the cell walls will rupture and provide nutrients for the pitched yeast to use during the adaptive phase (first 16 or so hours after pitching). I don't toss more than one sachet worth of yeast in a boil however...

Cheers,
TL

Be careful doing this. You may denature the proteins
See: http://www.homebrewandbeer.com/forum/vi ... php?t=1645

[Trough Lolly]

Be careful doing this. You may denature the proteins
See: http://www.homebrewandbeer.com/forum/vi ... php?t=1645

Hmmm, ok....so the only reference to this was here:

I rehydrate so that the killing of the yeast is instantaneous. That way, the yeast proteins are not completely denatured by the heat of a 10 minute boil. A quick splash in boiling water will not do this, but the longer time will.

I agree that during the boil, the proteins present in the wort are thermally denatured and we commonly observe this and refer to it as hot break, where we can see the coagulated protein in the wort. The important point that's overlooked is that there is plenty of protein left in wort after the boil to provide an ample protein nutrient source for the yeast that you pitch. Scientific studies dating back to the 1940's (I can quote them if you're sufficiently interested) suggest that boiling and the subsequent cooling of wort will remove no more than 35% of the total protein content and the protein extraction efficiency is largely determined by wort pH, the type of malt used and the type (pellets v flowers etc) and variety of hops used in the boil.
If all the proteins were denatured during the boil, you wouldn't see any cold break which of course is the coagulated proteins that have interacted with the polyphenols in the wort that were largely derived from the hops you used - hence the importance on what type and variety of hops you used. In fact, it's been argued that high bitterness hops or hop oils are responsible for poor protein removal during cold break formation since there's relatively less plant material in the wort, but I digress...
After pitching the fermenting yeast (not the sachet you want to destroy in the boil!), the yeast will undergo an adaptive phase as they acclimatise to the new wort / environment. During this period, the yeast will consume up to a further 65% of the available soluble proteins in the wort.

So yes, you will probably denature some of the proteins when you boil the sachet of yeast, but to be honest, that's not an issue since the malt already present in the wort has proteins available. There's other reasons why boiling a small quantity of yeast is worthwhile...

Yeast require a number of nutrients for growth, including vitamins, minerals, carbs, nitrogen and trace elements (including copper and zinc). A good source of nitrogen comes from the amino acids found in the wort. Yeast cells use the nitrogen to develop cell proteins and other compounds. There are roughly 20 amino acids and they are commonly found in the malt extract / wort that we use in beer brewing.
All of the wort amino acids and the small peptides are referred to as Free Amino Nitrogen or FAN. The FAN level in your wort is a good indicator of potential yeast growth and therefore fermentation performance. Cheap malt extracts are often low in FAN. A typical all malt freshly mashed wort has around 150 to 220 mg of FAN per litre. So any decent yeast nutrient should contain FAN...
Now, yeast has FAN levels of around 2% by weight, so, if you want to increase the FAN levels in your wort, you could toss in some yeast in the boil. Ok so it doesn't add all that much FAN but it does also add some zinc to the brew - which is an important yeast growth contributor - and whilst it's not a lot, it's better than tossing the sachet into the bin...There are other contributors that the yeast cells surrender, such as Vitamin B, but I think you get the point without boring you with too much more detail!
The boil does kill the yeast and it violently erupts the cells - as opposed to the cell breakdown via autolysis - so the boil assists by releasing nutrients into the wort from within the cells and even the cell walls themselves, which will help the fermentation yeast that's eventually pitched after the wort is chilled.
An alternative to this rather murderous endeavour is to purchase some true yeast nutrient, typically food grade mono or di-ammonium phosphate which is a good nitrogen source...

((And apologies to those who recognise the last few paras as a shameless cut and paste - to save re-typing - from a post I made on the Aussiehomebrewer forum back in April 2006)).
Cheers,
TL

[chris.]

Thank you

[NickMoore]

Be careful doing this. You may denature the proteins
See: http://www.homebrewandbeer.com/forum/vi ... php?t=1645

Hmmm, ok....so the only reference to this was here:

I rehydrate so that the killing of the yeast is instantaneous. That way, the yeast proteins are not completely denatured by the heat of a 10 minute boil. A quick splash in boiling water will not do this, but the longer time will.

I agree that during the boil, the proteins present in the wort are thermally denatured and we commonly observe this and refer to it as hot break, where we can see the coagulated protein in the wort. The important point that's overlooked is that there is plenty of protein left in wort after the boil to provide an ample protein nutrient source for the yeast that you pitch. Scientific studies dating back to the 1940's (I can quote them if you're sufficiently interested) suggest that boiling and the subsequent cooling of wort will remove no more than 35% of the total protein content and the protein extraction efficiency is largely determined by wort pH, the type of malt used and the type (pellets v flowers etc) and variety of hops used in the boil.
If all the proteins were denatured during the boil, you wouldn't see any cold break which of course is the coagulated proteins that have interacted with the polyphenols in the wort that were largely derived from the hops you used - hence the importance on what type and variety of hops you used. In fact, it's been argued that high bitterness hops or hop oils are responsible for poor protein removal during cold break formation since there's relatively less plant material in the wort, but I digress...
After pitching the fermenting yeast (not the sachet you want to destroy in the boil!), the yeast will undergo an adaptive phase as they acclimatise to the new wort / environment. During this period, the yeast will consume up to a further 65% of the available soluble proteins in the wort.

So yes, you will probably denature some of the proteins when you boil the sachet of yeast, but to be honest, that's not an issue since the malt already present in the wort has proteins available. There's other reasons why boiling a small quantity of yeast is worthwhile...

Yeast require a number of nutrients for growth, including vitamins, minerals, carbs, nitrogen and trace elements (including copper and zinc). A good source of nitrogen comes from the amino acids found in the wort. Yeast cells use the nitrogen to develop cell proteins and other compounds. There are roughly 20 amino acids and they are commonly found in the malt extract / wort that we use in beer brewing.
All of the wort amino acids and the small peptides are referred to as Free Amino Nitrogen or FAN. The FAN level in your wort is a good indicator of potential yeast growth and therefore fermentation performance. Cheap malt extracts are often low in FAN. A typical all malt freshly mashed wort has around 150 to 220 mg of FAN per litre. So any decent yeast nutrient should contain FAN...
Now, yeast has FAN levels of around 2% by weight, so, if you want to increase the FAN levels in your wort, you could toss in some yeast in the boil. Ok so it doesn't add all that much FAN but it does also add some zinc to the brew - which is an important yeast growth contributor - and whilst it's not a lot, it's better than tossing the sachet into the bin...There are other contributors that the yeast cells surrender, such as Vitamin B, but I think you get the point without boring you with too much more detail!
The boil does kill the yeast and it violently erupts the cells - as opposed to the cell breakdown via autolysis - so the boil assists by releasing nutrients into the wort from within the cells and even the cell walls themselves, which will help the fermentation yeast that's eventually pitched after the wort is chilled.
An alternative to this rather murderous endeavour is to purchase some true yeast nutrient, typically food grade mono or di-ammonium phosphate which is a good nitrogen source...

((And apologies to those who recognise the last few paras as a shameless cut and paste - to save re-typing - from a post I made on the Aussiehomebrewer forum back in April 2006)).
Cheers,
TL

Would you care to elaborate on that?

[ryan]

Aaaaaaaarrrrgggghhh.
{runs screaming from room holding head in hands}

[Trough Lolly]

Yeah, I thought a short quick answer would do the trick!

[chris.]

Maybe at the next Canberra Brewers meet you could sit down with Chris (The other Chris, the medical student - First degree in mircobiology, chemistry, & biochemistry) & debate this one over a glass of his RIS?

[Trough Lolly]

If there's stout, I'm there!

Cheers,
Bro Stout.