Yeast - General questions

[jarrodaden]

There are so many types of yeast. I know different yeast do different things better, but I don't really understand the science of it.

Can someone explain why certain yeast are better for certain brews?

I have also been reading up on yeast starters. I seems logical, that in addition to making a yeast starter, you could start cultures on specific yeasts and grow them yourself (never needing to buy again).

Do anyone have specific experience with this? Is is even practical for someone who brews a batch every month or so?

Thanks.

 

[Polboy]

Shortly, different yeast strains create different flavor profile, some add very little to the beer some add lots of flavor (ie belgian strains) so thats one thing. Then you have different temperature range for many strains so your fermentation conditions is something to consider when picking yeast, then you have attenuation, some will eat more sugars from your wort (high attenuation) some leave more behind giving higher final gravity, "sweeter" beer, then flocculation, some strains drop out of suspension fast giving clearer beer some require more time and at the end you have convenience of dry yeasts and huge selection of liquid so at the end pick the strain that you think will work for you and try it.
About reusing yeasts yes you can do it, there is several different ways, i keep some starter i make, cold crush and freeze yeast slurry with 10% glicerol in 2ml size vials, hen i want to use them i make 2 step starter

 

[Tinga]

Different strains act differently through the process of evolution. a yeast strain was used and it provided flavors the brewer liked then they split it between two batches and picked the one they liked best and so on and so forth until they had a unique strain that did different things than the original.

The viability of yeast would depend on how you are growing and cultivating the yeast. If you are simply brewing and washing the yeast it will start to mutate beyond what you want around 3-5 batches. so you should continue to buy yeast after that many. for someone that brews once a month I would say it isn't in your best interests to cultivate your own yeast and do the slants thing. What I do is since I brew mostly pale ales or IPAs is get a packet of US-05 and makes a batch with that then wash the yeast. I can get five batches of yeast if I split the initial yeast cake into four containers and use one container per batch. Then after those all are done I just go buy a new packet of US-05 rinse and repeat. It should be noted the viability of each container of washed yeast goes down after long term storage in a regular fridge. To what level is debated. so if you brew 5 gallon batches once a month I would say you could do 3 batches after buying one packet of yeast.

 

[jhayes3920]

Regarding different yeast it boils down to these yeast have beer cultured over years of use to eat specific thing in the wort and leave behind taste or no taste. They are just better at it then other yeast. Look at them like people and animals, we all have our mother and father to thank for who we are and yeast are no different. The use of them has led to the mutation or changes that happen inside the wort.

I have and still do use the left over yeast from my secondary to start my new batch of beer. I have used this to make 6 batches of beer racking the new beer on top of yeast is secondary. I refuse to do it more than that, out of fear of have the 7 batch go wrong. But if everything is clean it should be ok ... how far do I have to stretch a buck? I have also taken a 7dollar yeast boiled up 8 cups of water with 4 cup of hopped DME and let the yeast go to town on the DME. I would ether dived that and let ferment seperate or ferment out and dived after fermentation. This make 6 2nd generation yeast that can be stored in the frig in a capped bottle for later use.

Hope that helps