Starter necessary?

[sup3rh3ro]

This question has been asked before but I didn't get much of an answer.

I harvested yeast from a previous brew, which was about 2 months ago. I harvested it after bottling and used half of the harvest in my next brew which was just one week later. That beer fermented really well and quickly. I kept the remainder in a sterilised jar in the fridge now, where it has been sitting since.

As wer're going to have a hose pipe ban I decided rather spontaneously to do another brew today and I remembered that I had the yeast in the fridge still. Now I wonder.... why do people do a starter? When you buy fresh yeast from the shop (and those are usually smaller than the amount I have) as far as I am aware you can add that straight to the fermenting bucket without the need for a starter. Or similar with the dried yeast. I've never made a starter for that.

Thing is I don't have anything to make a starter with other than what people have in the cupboard lol. So the question is... can I chuck in the yeast I harvested or shall I open a new packet of dry yeast which I still have?

PS: it's going to be an IPA.

 

[RM-MN]

There are two schools of thought on harvested yeast being stored. One would suggest that after 2 months most of the yeast would be dead. The other has done a study that shows that refrigerated at the proper temperature, yeast only lose 1 to 2% viability per month. You get to choose which to believe.

 

[McMullan]

These yeast cells are dormant in famine conditions with viability declining. Make a starter to get them in a condition fit for repitching. No problem using what's only available in the cupboard. No reason why a starter can't be cultured in a pot used for prepping the starter wort, if you haven't got a big enough jar. Otherwise I think I'd rather use dry yeast than pitch dormant yeast slurry. There's a good chance you'll get a much longer 'lag' without making a starter, which risks infection and oxidation of the sweet wort. Note a starter is likely going to reduce the lag period typically observed when pitching dry yeast, too.

 

[McMullan]

There are two schools of thought on harvested yeast being stored. One would suggest that after 2 months most of the yeast would be dead. The other has done a study that shows that refrigerated at the proper temperature, yeast only lose 1 to 2% viability per month. You get to choose which to believe.

Is this study representative of all situations where home brewers store harvested yeast slurry? I'm >99% sure the answer is no. It's important to avoid viewing things in a binary manner. It's not necessarily representative of reality. I've heard this logic about "it's only 1-2% loss of viability/month" several times. If you have stored yeast slurry that's lost about, say, 5% viability, it doesn't mean the remaining 95% viable cells are in good enough condition to pitch without making a starter. By promoting delays in fermentation starting we're taking risks. This fallacy wet/liquid yeast is directly pitchable (without making a starter) after being stored for months is marketing speil. If you interogate the advice commercial wet yeast suppliers give to pro brewers, who generally repitch yeast, you'll note the recommendations are repitch stored harvested slurry within days, not months.

 

[sup3rh3ro]

Thank you both, that's interesting. Sounds like using a pack of dry yeast might be the better option, given that I would need the yeast to be ready in a couple of hours or so.

However, what "cupboard items" would work as a starter? In my naiivity "sugar" srpings to mind, but surely there is a reason why people usually use malt or even wort they froze previously?

That also begs the question... how long can I store yeast in the fridge? I assume if I freeze some wort today for next time, that yeast will be long gone (better off using yeast then from this batch but this one will be dry hopped and "green").
And another maybe silly question but: Can you freeze yeast or why can't you? I always freeze fresh bread making yeast to bake with with no problem. it springs into action in no time when used and is still far better than dried baking yeast.

 

[McMullan]

No, for the actual starter media you want to use malted barley wort, dry or liquid malt extract or do a mini mash to make your own. A pinch of yeast nutrients is recommended to help keep the yeast cells in good condition. Sugar alone is too nutrient deficient.

 

[homebeerbrewer]

I've revived 2 year old, store-bought, liquid yeast by using step starters. It takes time, but it can be done. That being said, if your slurry is a decent sized quantity, and it's only 2 months old, I'd say you can pitch it. You may have a little longer lag time, but it should ferment out without problems. Assuming your sanitation is thorough.

 

[MajorJC]

how long can I store yeast in the fridge?

Can you freeze yeast or why can't you?

Check out this article. Maintaining A Healthy Yeast Bank Long Term

 

[hottpeper13]

Take the yeast out of the fridge and decant on brew day morning. After the wort has boiled for 10 min. remove one quart and put in freezer to cool. When at pitching temps add to jar. It should be ready to pitch into the fermenter in 4-6 hrs (wow ,that's about how long brew day is). Lag time is always around 4 hrs,unless it's Kveik.