1 pack of liquid yeast to create 2 starters

[x3la]

I have a pack of Wyeast 1469 West Yorkshire Ale and intend to brew 2 x 5 Gallon batches of ~4-5%ABV English Bitter this week.

I have two Stir Plates and 2 x 2 litre Erlenmeyer Flasks and a big bag of DME.

Does anyone have a go-to quick and easy method for building two starters from one pack? (I typically top crop this yeast in order to re-use but haven't brewed for a few months so the fridge is bare.)

 

[RM-MN]

Build one starter batch, split it into 2 flasks and add more food for the yeast.

 

[Deadalus]

Get your four liters of wort ready and pour 2 liters into one flask. Then add the pack, stir (on the stir plate), then split half to the other flask and top off both with the remaining wort. A pack can ferment five gallons of low to medium gravity wort, it's enough for two 2 liter starters.

Personally I would have just eyeballed the pack between the two flasks.

If the yeast isn't particularly fresh, then you might want to account for that.

 

[KeizerBrewr]

Go to any website that does a starter/pitch calculator. Build a liter starter with 1.040 wort. See where the cell count lands(based off of the production date), split that in half(one for each flask). Take the halved number, punch it into the calculator and build as big of starter as you need. My one recommendation is to let the yeast settle out so you can decant some of the supernatant off before you add fresh wort.

 

[Deadalus]

Go to any website that does a starter/pitch calculator. Build a liter starter with 1.040 wort. See where the cell count lands(based off of the production date), split that in half(one for each flask). Take the halved number, punch it into the calculator and build as big of starter as you need. My one recommendation is to let the yeast settle out so you can decant some of the supernatant off before you add fresh wort.

Unless I am misreading, I think you are saying to build a one liter starter first? That's most likely not necessary here unless the starter pack was old. The rest of what you are saying would save some DME because the 2l size may be more than enough. It is if the pack is fresh.

If the brewers friend calculator was used, the viability of the yeast is provided when the manufacturing date is entered. So multiply that by 100 billion then skip down to part 2 and use that number to build the correct size starter based on the desired OG. I did that originally just to check to see if a calculator would support splitting the pack (50 billion cells). I assumed it was fresh. I am not too confident that the viability estimate is accurate, which is why I said "isn't particularly fresh".

 

[KeizerBrewr]

Unless I am misreading, I think you are saying to build a one liter starter first? That's most likely not necessary here unless the starter pack was old. The rest of what you are saying would save some DME because the 2l size may be more than enough. It is if the pack is fresh.

If the brewers friend calculator was used, the viability of the yeast is provided when the manufacturing date is entered. So multiply that by 100 billion then skip down to part 2 and use that number to build the correct size starter based on the desired OG. I did that originally just to check to see if a calculator would support splitting the pack (50 billion cells). I assumed it was fresh. I am not too confident that the viability estimate is accurate, which is why I said "isn't particularly fresh".

That's exactly what I am saying. It may not be, be but the OP said two 5 gallon batches of roughly 1.045OG wort. Assuming the yeast is at most a month old, that would be roughly 80b cells. A safe pitch rate is 0.75m/mL/°P. A liter starter would get 214b cells, split in half(107b). That would make it simple to split in half and then 1.040 liter starter for both will be more than enough. Ensuring yeast health and viability is important, I don't rush on starters even if its for a low ABV beer. A second step is simple.

 

[Deadalus]

That's exactly what I am saying. It may not be, be but the OP said two 5 gallon batches of roughly 1.045OG wort. Assuming the yeast is at most a month old, that would be roughly 80b cells. A safe pitch rate is 0.75m/mL/°P. A liter starter would get 214b cells, split in half(107b). That would make it simple to split in half and then 1.040 liter starter for both will be more than enough. Ensuring yeast health and viability is important, I don't rush on starters even if its for a low ABV beer. A second step is simple.

You may not be but if you are accepting the calculator, why not simply make a 2l to start with at 1.036. With 80b cells to start with the ending cell count is 348b cells and the pitch rate is 1.64M cells/ml/°P. Divided by 2 is 0.82M cells/ml/°P and 174b cells.

I think you worked it backwards for a two step starter as your numbers result in 319b cells, which suggests you do it that way often, but a second step is not simple it is almost 2x as much prep work. I'm not criticizing your philosophy. However the OP was looking for go to quick and easy for 2 two liter starters with the equipment they have.

 

[day_trippr]

I've been so enamored with the Brew United/Homebrew Dad's Yeast Calculator I have to put a big fat plug in here for it
It is loaded with goodness, including a way to specify an overbuild cell count, for those who ranch their yeast...

http://www.brewunited.com/yeast_calculator.php
Anyway, for the OPs ask...without knowing the "born on date" for the 1469, there's some uncertainty here, but as one can only fit about 1.5 liters in a 2 liter e-flask, I would go with the "split the pouch" idea, use whichever calculator is favored and simply plug in the numbers for one of the 5 gallon batches, then apply the result to both e-flasks...

Cheers!

 

[CascadesBrewer]

I have a pack of Wyeast 1469 West Yorkshire Ale and intend to brew 2 x 5 Gallon batches of ~4-5%ABV English Bitter this week.

Personally, if the yeast is fairly fresh, I would be fine with making a single 1.5L starter and pitching that yeast into 10 gallons of 1.045 wort. Or divide up the yeast and make a pair of 1L starters adding half of the yeast into each flask.