re-using rinsed yeast

[duotwr]

Hi,

I bottled a brew a couple of weeks ago which used Safale US-05. After I'd transferred from the primary I washed out the settled yeast, and transferred it to a couple of small jars - which have been sitting in my fridge for a couple of weeks.

I'd like to use these for a brew this week - how do I do it? Do I need to make a starter to get them active again, or can I just bring them up to room temp and pitch directly into the wort? I do BIAB and my batches are only around 10 or 11 litres. The yeast is in 250ml jars - and has settled to about 1.5cm in the bottom of each.

I've seen the Mr Malty calculator - a quick play with it suggests around 100ml of slurry. Presumably this would be the slurry I get when I shake up one of my settled jam jars?

Any advice gratefully received!

Keith

[crimsongarlic]

When I use Mr Malty for yeast which has been in the fridge for a week or two I just slide the 'yeast concentration' slider right up to 'thick yeast' to work out how much I need.

I then pour off most of the liquid from above the yeast and gently shake the rest back into suspension and add to a small starter while my wort is cooling (usually takes a few hours for me to cool it) by which time the yeast should be working nicely. I pour this into the cooled wort.

Someone with more experience might be able to give you better/more thorough advice.

[duotwr]

Thanks for the reply. I'm brewing this weekend so was just concerned I needed to get a starter going today - but sounds like that's not necessary. I'll see how I get on.

Keith

[crimsongarlic]

If you've got sufficient yeast you should be alright. I usually have a pack of dried yeast ready as a backup.

[Jocky]

Presuming you washed the yeast to get rid of the trub from the old batch, one of your jars sounds like plenty of yeast.

As you have said, bring up to room temperature, decant most of the liquid, shake up well and then pitch as normal.

[Jonnyconga]

The way I look at it is when pitching dried or liquid yeast there isn't much volume there. If you've got 1.5cm in a jar that's quite a lot - esp for a smallish batch. I normally do a starter but I'm not sure it's always necessary. I normally let my starter go over night before the brew - hoping there's a krausen line in the morning..!

[6470zzy]

Sounds as though you will be fine. Just make sure to aerate your wort properly as you are going to be using a fresh liquid yeast, they will be looking for lots of oxygen to get themselves off to a good start.

Cheers