Splitting and stepping up a starter

[ChandlerBang]

I got some WLP300 Hefe yeast from the LHBS today that is super old. It was the only hefe yeast he had... I don't want to wait till I can get an order from somewhere else... yada, yada... And he gave to me for like three bucks...

I have (2) 5 gallon batches that I want to use this yeast for next weekend, here is what I'm going to do.

1 liter starter straight from the vial. I used 85 grams of light DME in ~850 ml of water. I think I read the 10 to 1 thing on MrMalty, but I don't know how to calculate the actual OG.
If the yeast is viable, I'm going to split it and do the same size starter for each of the two spits again towards the end of the week. Or I have a jar big enough to just do a 2 liter starter and roughly split that into the buckets when ready. Thoughts?

MrMalty says I need a 1 liter starter (stirplate) for each batch ~1.051 OG.


And is there a resource somewhere that explains yeast growth in starters a little better than the general conversations on here? Like how starting amounts of yeast, OG of starter wort, wort volume, all affect total growth? Stuff like that.

TIA

 

[BBL_Brewer]

Either of the two methods will work. DME usually contributes anywhere from 40-50 PPG, 85 grams into 850 ml should give you a gravity between 1.035-1.040 which is perfect for starters. If you have a stir plate (and a jug big enough) just make up one large starter and split that at pitching time. If you don't have a stir plate, you might be better off splitting into two separate starters.

 

[Clementine]

The best reading I have found is the maltose falcon website link here http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

One note if you are using the formal listed on this website to calculate pitching rates I did notice they had a 1-OG when it was meant to be OG-1 in one location.

There will be some viable yeast in the vial and so you can step up your starter I would do the vial into 1L and then see how it goes if it is really sluggish decant and do a 1L again. Even if there was only 1% viability that will still leave you with 1Billion Yeast cells that can easily grow out to the required amount in two or three steps.

Then split the starter into two and do two 1L starters. I found doing 10 gallon batches that I best off having one starter per fermentation vessel else while pitching you can just take back the yeast if you put too much in the first vessel not leaving enough for the second. Also if you mess up somewhere in your process you have viable yeast that you can step up again to replace one of the contaminated starter.

Clem

 

[ChandlerBang]

That is some great info. Thanks.

You mention a sluggish start? It has been on the stirplate for 12 hours and I see no signs of activity. I am new to the whole starter thing (this is my 3rd) but usually in this amount of time, the color changes or there is a little indication of krausen on the glass just above the liquid. How slow is slow?

 

[samc]

Often you will not see much action with a starter. A layer of yeast on the bottom is a good sign as well as the smell and taste being clues. Old yeast might take longer to get going so be patient.

 

[ChandlerBang]

Often you will not see much action with a starter. A layer of yeast on the bottom is a good sign as well as the smell and taste being clues. Old yeast might take longer to get going so be patient.

Yeah good call. It smells like fermentation is happening, although no visual changes have happened.

 

[Clementine]

Given the age of the yeast pack you will have to be patient. if it goes past 24 hrs then I would put this in the sluggish box and put be prepared to do a second step in the starter. There are often massive discussions on what is slow for a starter so not wanting to start anything like that, just 12 hrs after pitching you should see signs of your starter fermenting, if it is not then it is less than ideal. However it does not mean it is dead just your yeast cell count may not be as high as and ideal setup. So crash cool decant and add more wort and go again, you will notice the next one will take off a lot quicker.

With the stir plate you will notice and increase in the amount of CO2 being driven off by the stirring action and also a krausen will still form for the aggressive fermenation of a starter (note your first one might be so sluggish that it does not krausen at all). When you stop the stir plate yeast will settle out and it will look like the bottom of a white labs vial. If you have trub in your starter it will settle out first and then a layer of white yeast cells will settle out on top of that. Different yeasts have slightly different colors. I notices WLP380 is quite brown compared to WLP001, that could be because it does not flock as well or a function of the yeast itself.

While the stir plate is going you will notice a chance in color, I'm not sure if this is due to the density increasing, CO2 bubbling from the stirring action cells starting to flocculate but being spun around by the stir bar but you may notice a color change. I recently made a batch of Nottingham on the stir plate, the yeast flocculated while on the stir plate. So when I stopped the stir it was already chucks of yeast floating around, that then settled to form the cake at the bottom.

Clem

 

[BBL_Brewer]

I've noticed that the stir plate starters get milky looking when they are done. Sometimes it's hard to catch the krausen occur as this goes up and down pretty quickly. Also, you can see wavy lines in the starter when it's done, I think this is yeast trying to settle out.

 

[ChandlerBang]

Well looky there. She's foaming a little bit and changing colors. It only took 36 hours.

I'm going to put it in the fridge tomorrow morning then decant and add the same size/OG starter wort to it again on maybe Friday. Then I'll double the size maybe Saturday evening and it should be ready to pitch right in Sunday afternoon?

How important is it to keep light off of the starter?

 

[samc]

No hops so light isn't an issue AFAIK.

 

[Clementine]

As this is a hefe yeast it takes longer for it to flock out to the bottom. I found WLP001, nottingham, wlp029 and other stuff that is high to medium flocculation settle out within 12hrs and then by 24 -36 the cake on the bottom is rock solid. I use WLP380 for my hefes and it is always about 12 to 18hrs behind so give it a good while in the fridge and decant really gently. You know when it is ready to decant when the wort on top clears and the yeast does not kick up off the bottom when you pick it up to inspect.

Good luck

Clem

 

[ChandlerBang]

No hops so light isn't an issue AFAIK.

Oh hops are the issue with light. I think I read that somewhere.