Alternatives for yeast nutrients?

[shopkins1994]

Hi Everyone. I was wondering if anyone had any input on alternative yeast nutrients that would be readily available in the kitchen. Peanut butter seems to be a good one but it has a strong smell/taste. Any other ideas?

I'm trying to find a different source other than commercially available yeast nutrients. In other words, I want to make my own from readily available food that I could buy from Walmart, etc.

Thanks,

Sam

 

[ArcaneXor]

You can add yeast during the boil as a makeshift nutrient.

 

[SmokeyMcBong]

Bread yeast or raisins.

 

[Brewmex41]

I have some jars of yeast in the brew fridge. I didn't label them and after I moved I forgot what they were. So I have been adding them to the boil and been buying new yeast and making sure to label them!

 

[JKaranka]

You can add some Marmite: cheap and edible too.

 

[giraffe]

Ive heard bee pollen can work as well.

 

[uncleleon]

+1 for yeast trub in the boil. Or you could go all grain?

 

[Warthaug]

You can add some Marmite: cheap and edible too.

Let agree to disagree...

 

[Legume]

I have been making high adjunct beers lately, and have had diacetyl problems as a result of the low FAN ( valine specifically).
In my last batch I added protease (gluten cutter pills from wallgreens) and powdered egg whites (baking aisle at the grocery store), to bump up the levels of valine in the wort....It semes to have worked.

adding bakers yeast to the boil would probably do the trick too.

 

[jbaysurfer]

^ what role does valine play in diacetyl production? Honest question. I geek out alot on this stuff and for the life of me can't even remember learning anything about valine.

PS: Holla from a fellow 805er!

 

[RmikeVT]

Hi Everyone. I was wondering if anyone had any input on alternative yeast nutrients that would be readily available in the kitchen. Peanut butter seems to be a good one but it has a strong smell/taste. Any other ideas?

I'm trying to find a different source other than commercially available yeast nutrients. In other words, I want to make my own from readily available food that I could buy from Walmart, etc.

Thanks,

Sam

I've heard malted barley stewed in hot water between 148-158 degrees F for an hour makes great yeast nutrient.

 

[suregork]

^ what role does valine play in diacetyl production? Honest question. I geek out alot on this stuff and for the life of me can't even remember learning anything about valine.

PS: Holla from a fellow 805er!

Short version: Diacetyl is a byproduct of valine biosynthesis in yeast.

Long version: Yeast need amino acids for growth and protein synthesis. If the yeast can't assimilate sufficient amino acids from the wort, it must synthesize its own. Valine (,leucine and isoleucine) is/are synthesized through the ILV-pathway. In the case of valine, pyruvate (a key intermediate in several metabolic pathways) is first converted to alpha-acetolactate (AAL) through the action of the acetohydroxyacid synthase (AHAS) enzyme. AAL is then further converted to valine through a series of reactions. Typically, AAL is produced in excess, and it leaks out of the cell into the wort (the actual reason for this is still unknown). In the wort, AAL is then converted into diacetyl. Valine feedback-inhibits the acetohydroxyacid synthase (AHAS) enzyme, that converts pyruvate into alpha-acetolactate, which means that the more valine that enters the cell, the less AAL is produced and thus the less diacetyl is produced as well. Be careful though with raising the FAN level too much (i.e. adding too much amino acids), as it can actually have the opposite effect of increasing diacetyl production (as well as higher alcohol and ester production)! Why is that? Well, one would think that a high FAN value would automatically result in less diacetyl, since more valine is present in the wort, but this is not always the case. For the valine to inhibit the AHAS enzyme, it must be transported into the cell. Amino acids are transported into yeast cells through various transporters in the membrane. Valine is taken up through several transporters, but none of them are specific for just valine (i.e. they transport other amino acids as well). When the amino acid concentration of the wort is increased, the competition for these transporters increases as well, and as a result less valine is actually taken up (adding pure valine or an amino acid mix high in valine would of course not result in this). A good target FAN value for optimal fermentation yet low diacetyl formation is in the 150-300 ppm range.

For more information, see this recent review: http://onlinelibrary.wiley.com/doi/10.1002/jib.84/abstract

 

[grathan]

I've been trying to add Valine powder lately, but it seems highly hydrophobic and I am not convinced it is even hydrating when added at the beginning of the boil.

 

[suregork]

I've been trying to add Valine powder lately, but it seems highly hydrophobic and I am not convinced it is even hydrating when added at the beginning of the boil.

You can try making a solution in water first (30 g/L is easy to dissolve). A boost of 250 ppm valine should approximately double the valine level in a typical wort. For this you would need to add 0.15 liter of the 30 g/L solution to a 5 gallon batch (18.9 L).

 

[fantomlord]

I've been trying to add Valine powder lately, but it seems highly hydrophobic and I am not convinced it is even hydrating when added at the beginning of the boil.

Valine has about the same solubility as sodium bicarbonate at room temperature (~8.5%)

 

[MindenMan]

Even though I have DAP, and Fermaid K which contains DAP, just good ol' bread yeast added to the boil by itself, will make a huge difference. I added just boiled bread yeast to a starter once, (and ever since) and the speed of the starter growth was like none I had ever seen before. A one pound bag of bakers yeast at WINCO is less than $4.00.

 

[jbaysurfer]

Short version: Diacetyl is a byproduct of valine biosynthesis in yeast.

Long version: Yeast need amino acids for growth and protein synthesis. If the yeast can't assimilate sufficient amino acids from the wort, it must synthesize its own. Valine (,leucine and isoleucine) is/are synthesized through the ILV-pathway. In the case of valine, pyruvate (a key intermediate in several metabolic pathways) is first converted to alpha-acetolactate (AAL) through the action of the acetohydroxyacid synthase (AHAS) enzyme. AAL is then further converted to valine through a series of reactions. Typically, AAL is produced in excess, and it leaks out of the cell into the wort (the actual reason for this is still unknown). In the wort, AAL is then converted into diacetyl. Valine feedback-inhibits the acetohydroxyacid synthase (AHAS) enzyme, that converts pyruvate into alpha-acetolactate, which means that the more valine that enters the cell, the less AAL is produced and thus the less diacetyl is produced as well. Be careful though with raising the FAN level too much (i.e. adding too much amino acids), as it can actually have the opposite effect of increasing diacetyl production (as well as higher alcohol and ester production)! Why is that? Well, one would think that a high FAN value would automatically result in less diacetyl, since more valine is present in the wort, but this is not always the case. For the valine to inhibit the AHAS enzyme, it must be transported into the cell. Amino acids are transported into yeast cells through various transporters in the membrane. Valine is taken up through several transporters, but none of them are specific for just valine (i.e. they transport other amino acids as well). When the amino acid concentration of the wort is increased, the competition for these transporters increases as well, and as a result less valine is actually taken up (adding pure valine or an amino acid mix high in valine would of course not result in this). A good target FAN value for optimal fermentation yet low diacetyl formation is in the 150-300 ppm range.

For more information, see this recent review: http://onlinelibrary.wiley.com/doi/10.1002/jib.84/abstract

This was great. Thanks. I surmise that FAN is a neccesary component for Valine production, but wasn't sure on that front. I know certain levels of FAN are key in yeast health...but not entirely sure of it's relationship to valine.