harvested yeast volume for new starter

[brcisna]

Hello All,

New to the brew scene. Getting ready to brew my third batch / 5 gallons,,,this one , of Newcastle dark ale recipe.

Have read many tutorials , including the nice STICKY here in regard to harvesting your yeast cake and either doing the "simple method" or 'rinsing' method.
Even after watching and seeing in a tutorial a spread sheet of how to calculate how many billion cells you actually have in a yeast harvest,,,I've never actually seen if it best to just do a starter with the entire amount of the harvested yeast or if you can say make a starter with only half the amount of harvested yeast and you'll have sufficient yeast supply for your new batch of beer.

Still haven't gotten my head around how the yeast actually populates,etc. It appears you should theoriticaly end up with way more yeast cells then when you actually started your fermentation process,,so it would appear you could use way less than the entire amount of your harvested yeast?
Sorry for long post.

Thanks

 

[LLBeanJ]

First off, forget rinsing. It's a pain in the arse and there is rarely a good reason to do it. There are much easier ways to achieve the same result with less potential exposure to contaminants.

With regard to harvested yeast slurry, you can either direct-pitch it into another batch of wort (no starter and no rinsing needed) or you can take a small portion, say around 1/4-1/2 cup and use it to propagate a starter. Whether you do one or the other depends on the viability of the slurry. If it's less than a month or two old and it's been kept cold in the fridge, you can skip the starter and direct pitch. If it's older than that or if you want to save the yeast in relatively clean form for longer term storage (up to about a year, give or take), you'll probably want to make a starter.

It really doesn't take that much yeast to ferment a batch of beer and even less to make a starter. The yeast cake you're left with after a batch of beer has fermented is typically enough to ferment about four more batches of the same volume and gravity. One cup of fermenter slurry would easily ferment a 5 gal batch of 1.060 wort.

 

[brcisna]

LLBeanJ,

Thanks for the info. This reply makes things even that much simpler for the batch i'm about to brew.
This yeast was harvested just one week ago,so just going to pitch about a third 'simple save status' into my new recipe of Newcastle dark ale. Not even sure what strain of yeast this is without looking/ it came with a charlie brown dark ale recipe,,,though.

Thanks