Stepping Up Starters - WHILE USING A STIR PLATE

I use it in subsequent starters. 1/4 of an Activator is 1 Propagator so I am using what Wyeast would give you to start a starter. It is a way to stretch out a pack of yeast.

 

What do you store it in? How long? I'm interested in saving a buck without washing which seems like too much hassle for me

 

These days I just pour it from the pouch into a jar. When it is time to make a starter I just swirl it up and pour out what I estimate to be 25ml, which is 1/4 of the 100ml yeast they give you.

It will last as long in the jar as the pouch so just write the manufacture date on the jar and proceed as usual.

Again, not very exact but it works out every time.

 

You have me intrigued. Do you know what strength microscope you would need to see S. cerevisiae? Would 1000x be enough?

 

Maybe this could help : http://homebrew.stackexchange.com/q...power-of-microscope-for-observing-yeast-cells

 

Oh yeah. Its debatable whether 40X can do it well, but 100x wil no problem.

 

Great, thanks!

 

Just to respond to this question: there is absolutely no reason that keeping the yeast on a stir plate would be detrimental to their health, as long as they are fed and oxygenated appropriately.

 

I don't think anyone's ever mentioned that the yeast of a IIPA is going to be stressed. I'm not sure what kind of beer you're going to try to make but I'd try to overpitch a little. I'd also try to ferment cool.

 

As long as the agitation is not too great, they should not be stressed due to stirring. In fact, stirring keeps them in contact with food and oxygen, and should improve their vitality.

 

That would be a 100x objective and a 10x eyepiece, which gives your 1000x.

 

Just to add a bit of confusion to the thread, wasn't it mentioned in the Heady Clone thread that Kimmich routinely underpitches Conan, also in Steele's IPA book IIRC?

My first two Conan beers are delcious BTW, def. worth harvesting from Heady. The first one may well have been underpitched, despite careful starter step ups, as it took almost 2 weeks to finish. Second one will be bottled Sunday, pitched onto cake, stunning flavor from flask.

 

I have done #2 exactly as you described with no problems. In my fridge is a mix of washed yeast in sterile water and re-harvested yeast in starter-wort (actually very bland beer). In both cases I fill the jar to overflowing before capping . . . zero headspace. Fridge temp is only about 40 which isn't ideal for storing yeast, but so far so good.

When I'm ready to use my harvested yeast I decant the starter-wort, warm to room temp, and re-start . . . it takes off like a house on fire and fermentation has been as expected.

 

For the 18 gallon batches we usually brew we do a one gallon starter, let it go for 2 days and then pour the whole thing into a 2 gallon starter. That goes for 2 days. After that we crash it and decant. It has worked well so far. ( no stir plate )

 

According to Yeast, "initial oxygen content" is one of the factors that determine the degree of flocculation. It also states that the presence of oxygen "inhibits" flocculation. But as you know, time and cold-ness tends to be the major player in having your yeast settle out. The content of these statements is general fermentation, but I don't see where it would be different in storing re-harvested yeast.

I offer that simply taking your starter off the stir plate for the last 24 hours will decrease residual O2 (at the slight expense of growth). My experience is limited, but I have stored yeast in starter-wort and had no trouble re-starting/pitching. The extra steps you discuss certainly make sense, but I have skipped them.