I'm hoping to get a response from a Lallemand representative on this one.
Our Brewery has decided to explore the possibility of propagating up pitchable quantities regularly to reduce our need to harvest from tank bottoms.
To make the whole process work we need to achieve about 200 Million cells/ mL in the final propagator slurry.
We have conducted several test propagations varying between 3 and 10bbl- some of which have been agitated and some have not.
We started in the small 3bbl tanks and have moved to the 10bbl agitated vessel and slowly changed conditions with each test.
Specs are as follows-
10 degree plato all malt wort
pitched at 8.5 Million cells/mL
Temperature held at 75F
Continuous flow of sterile O2
Continuously agitated (10bbl only)
Standard fermentation quantity of yeast nutrient added to kettle
Early on we realized we weren't adding nearly enough Oxygen which was an easy fix
Each prop. hits terminal gravity in about 24 hours but fails to breach 100Million cells/ml.
We have actually pitched a couple large tanks with said propagator slurry with equal or greater fermentation characteristics (which is partially successful).
I don't know what is holding us up from the 200Mcell/ml mark and the agitation didn't seem to make much of a difference in growth.
I feel like I am using adequate Oxygen so I will mark that off.
With that being said I feel like there must be other nutrients holding up cell growth. Amino acids and other nutrients (Zn, Nitrogen, etc.).
With that idea I considered increasing the wort gravity but if this works that won't really be an option when put in to full production mode.
So the next thought is to load on the yeast nutrient. If my thinking is correct here what nutrient blend would you recommend and how much over standard fermentation addition rates would you recommend?
Is there something I'm overlooking?
Thanks and let me know if I left out any important details.
N
Our Brewery has decided to explore the possibility of propagating up pitchable quantities regularly to reduce our need to harvest from tank bottoms.
To make the whole process work we need to achieve about 200 Million cells/ mL in the final propagator slurry.
We have conducted several test propagations varying between 3 and 10bbl- some of which have been agitated and some have not.
We started in the small 3bbl tanks and have moved to the 10bbl agitated vessel and slowly changed conditions with each test.
Specs are as follows-
10 degree plato all malt wort
pitched at 8.5 Million cells/mL
Temperature held at 75F
Continuous flow of sterile O2
Continuously agitated (10bbl only)
Standard fermentation quantity of yeast nutrient added to kettle
Early on we realized we weren't adding nearly enough Oxygen which was an easy fix
Each prop. hits terminal gravity in about 24 hours but fails to breach 100Million cells/ml.
We have actually pitched a couple large tanks with said propagator slurry with equal or greater fermentation characteristics (which is partially successful).
I don't know what is holding us up from the 200Mcell/ml mark and the agitation didn't seem to make much of a difference in growth.
I feel like I am using adequate Oxygen so I will mark that off.
With that being said I feel like there must be other nutrients holding up cell growth. Amino acids and other nutrients (Zn, Nitrogen, etc.).
With that idea I considered increasing the wort gravity but if this works that won't really be an option when put in to full production mode.
So the next thought is to load on the yeast nutrient. If my thinking is correct here what nutrient blend would you recommend and how much over standard fermentation addition rates would you recommend?
Is there something I'm overlooking?
Thanks and let me know if I left out any important details.
N
Comment