Cheers Hogan , You saved me a lot of reading :super: I have too many books and so little time for me to reference. Dr Kristen is a highly respected person that knows the stuff and is looked upon as a innovator in the brewing sciences.I must add that Wyeast does have 1040 as the best OG but I cant say why but I will ask.PM - here's a post from Dr Kristen England that supports the 1.025 rule. It was posted on another forum.
So take your WLP vial and pitch it into say 500ml of 1025-30 starter. People make starters WAY to high in OG. You make it 1025 the only thing you are doing is creating baby yeast. SO...say 3 days or so around 21-24c. Pitch that whole thing into a 2L starter. Few more days...maybe 3 or 4. For both, swirl anytime you can. You should have a good .5-1" of yeast on the bottom of a 2L flask by now which is more than enough yeast. This keeps you from having to do 6.5L starters
Kristen England, Ph.D.
BJCP Continuing Education Director
Master Judge
Cheers, Hoges.
Edit: Post info. Avitar - mashweasel http://forum.northernbrewer.com/viewtopic....&highlight=
.... I just remember (as others also seem to) 1.040 as being the optimal for cell growth, even if you're tossing the starter and just pitching the left over slurry.
You nailed it!>I have certainly heard that a lower gravity is better for starters because there is less osmotic stress on the yeast and that makes for healthier division. Basically you want the yeast to multiply in as healthy a condition as possible. Plenty of dissolved oxygen and low osmotic pressure makes for healthy yeast. The numbers i have heard are 1040 or below. Never heard 1025, but it might be good > Read Hogans post by Dr Kristen.GB, we are hosting Chris White here in Tokyo tomorrow, so I will ask him about it. I have certainly heard that a lower gravity is better for starters because there is less osmotic stress on the yeast and that makes for healthier division. Basically you want the yeast to multiply in as healthy a condition as possible. Plenty of dissolved oxygen and low osmotic pressure makes for healthy yeast. The numbers i have heard are 1040 or below. Never heard 1025, but it might be good under controlled laboratory conditions or something.
Hi Zwickel, No bodies English/German is good enough to explain the Crab Tree effect in simple terms. B) Yes what you say is very relevant to the point of low SG starters.It also explains stuck fermentations on high OG brews.The yeast just doesnt like it .Im with Gryphon Brewing, due to the "Crabtree-effect", for a fast cell growth its recommended to keep the sugar content very low.
Sorry, my english is not good enough to explain the crabtree-effect, I only can say, that the higher the sugar content of the solution, the more impermeable the cell membrane will become. In other words, a high sugar concentration is hampering the metabolism of the yeast cell.
just have a look here: http://www.rpi.edu/dept/chem-eng/Biotech-E...n/overload.html
cheers
Kristen England, Ph.D.
BJCP Continuing Education Director
Master Judge
Im with Gryphon Brewing, due to the "Crabtree-effect", for a fast cell growth its recommended to keep the sugar content very low.
Sorry, my english is not good enough to explain the crabtree-effect, I only can say, that the higher the sugar content of the solution, the more impermeable the cell membrane will become. In other words, a high sugar concentration is hampering the metabolism of the yeast cell.
just have a look here: http://www.rpi.edu/dept/chem-eng/Biotech-E...n/overload.html
cheers
PM any reference to your thoughts ? I think that what has been put forward would educate the forum contrary to your example.We are talking yeast growth bio mass not fermentation..
My thoughts on it were that if you pitched a tube of WLP001 into 1-2 litres of 1.025 wort they would ferment everything out without so much as doubling their numbers. More sugar + O2 gives them more material to build new cells. Too little sugar and they'd be heading for the bottom in a couple hours.
sure its been discussed before, but I only got a few mins, and am starting the brew tomorrow morning!
I'm using the WLP001 yeast for a 52L batch of the little creatures bright ale clone. I obviously don't have time to make a starter by tomorrow morning, so is it ok to pitch the whole vile of liquid yeast straight in?
Also, the recipe includes irish moss. Not exactly sure what this is, and I dont have it.. will it make a difference. Thanks for any help
edit: bright ale, not pale
PM any reference to your thoughts ? I think that what has been put forward would educate the forum contrary to your example.We are talking yeast growth bio mass not fermentation.
GB
Not at all GB. I'm very uneducated when it comes to yeast.
My naive understanding is (was) that the yeast will reproduce until they have the numbers to ferment the wort they're in. Pitching a vial made for 21L of 1.050 or so wort into 1 litre of 1.025, I thought, would lead to all the sugars being consumed and made into ethanol then the yest dozing off... it is clear I have a lot to learn. I can see where pitching a very small number of cells into the same wort would lead to reproduction. Anyway, as I said, yeast life cycle is not my forte.
Hi
You can pitch the tube straight into 20 litres, but a starter is a better way. Even though you don't have enough time to kick off a fully active starter, it still would be good to get the yeast multiplying and growing before pitching into your wort.
If you can, get a starter going 2 or 3 days before your batch.
Cheers
Pedro
Yeah, but you have to focus on the original question.
ok... I pitched a 1litre of the yeast yesterday... and I'm not seeing any action.
I used the yeast with 100g dextrose, 1l water, and and let the starter go for a bit over 24 hours. Pitched 500mls into each fermenter yesterday, and I'm still on the OG...
wort still tastes and smells great.. just no action.. you guys think it still could happen?