Harvested Yeast/ Yeast Starter Questions

[mkyl428]

I harvested and washed some wlp001 a couple months ago using some methods i found on youtube. I have been afraid to use it out of fear i might not have done it right, but i think i might be willing to try it out on my next batch i brew... I plan to brew Sunday or Monday I have purchased a 2000ml flask but have yet to make a starter in it. So I have a couple of questions

1. What type of DME should i buy? does it matter?

2. How strong should i make the wort? (I don't need to hop it do I?)

3. How much wort should i make?

4.When should i make my starter.... how far in advance?

5. Is there a way to tell if the yeast is any good, or is it basically if the starter ferments it's good to go? (I mean is there a way to tell if i contaminated it or something before i pitch my starter into 5gallons of wort I worked all day on)

Thanks in advance! This forum is so helpful in learning about this hobby it's nice to have a community of people so willing to help one another learn

 

[sweetcell]

1. not really. generally people use extra light, light, golden, etc. that way any starter you transfer to your main batch won't alter the color.

2. 1.035 - 1.040. rule of thumb: 1 gram of DME per 10 ml of water. so if you are making a two liter starter, use 200 gr of DME.

3. depends on many things, like how old the yeast is and what beer you're pitching it into. go to http://www.mrmalty.com/calc/calc.html and use the "repitching from slurry" tab to work out how much straight slurry (no starter) is required. if you don't enough enough viable cells in there to pitch directly, figure out how many cells you have and then plug that number into the "liquid yeast" tab. for example, the tool might tell you that you need 210 billion cells, which works out to 600 ml of your slurry. but you've only got 200 ml of slurry, or 1/3 of the required amount - so you have 70 billion cells. plug 70B into "liquid yeast" and see how big a starter you need (be sure to move the slider below all the way to the right, so that "# of vials or packs needed" is equal to 1.

4. if on a stir-plate, should be done in 24 hours. if just shaking, give it 72. then, ideally, cold-crash it in the fridge for 48 hours. on brew day, take the starter out of the fridge a few hours in advance of pitching to warm up. just before pitching, pour off 90% of the "beer" above the yeast cake, then swirl the remaining beer with the cake to re-suspend. pitch.

5. your washed yeast should smell like yeast, the starter should smell like oxidized beer. challenge: knowing what those two things smell like. also, the starter "beer" should taste like oxidized beer. it shouldn't be sour/acidic, etc.

 

[mkyl428]

Okay using the mr.malty calc it says i should need 194 billion cells or 824ml of slurry I will have to figure out how to measure the amount i have later, but let's say for the sake of learning that i have 200ml of slurry. So that would be about a quarter of what i need so about 49 billion cells give or take right? I don't see where to plug that into the liquid yeast tab

 

[sweetcell]

So that would be about a quarter of what i need so about 49 billion cells right? I don't see where to plug that into the liquid yeast tab

yup, you're on the right track! easiest way to get mrmalty to recognize 49b cells is to un-check "Calculate Viability from Date", and enter 49%. both wyest and white labs put 100b cells in their retail packages, so the percentage = billions of cells. then proceed with the rest of the "Liquid Yeast" tab: select what kind of a starter you'll be making from the drop-down and check out the numbers. don't forget to move the slider below all the way to the right, so that "# of vials or packs needed" is equal to 1.

 

[mkyl428]

Okay with some googling I found http://www.yeastcalculator.com/ so I put the 49billion cells in as my initial cell count. I'm guessing i should turn off the calculate viability option since i already calculated my cell number with mr.malty So if i leave all the other settings at their default I should need a 2 liter starter with intermittent shaking to get to 173 billion cells and then another 1liter starter would put me at around 255B cells just a bit more than i need... am I understanding this correctly?

 

[mkyl428]

Sorry i didn't see your previous post before i looked up that other calculator

Okay so back to mr.malty so if I am fermenting an ale wort with an OG of 1.053 with 49B cells or 49% in the viability box I should need about a 2 1/2 liter starter right? which I'm guessing my flask won't hold so I guess I should do maybe a 1.5 liter starter followed by a 1 liter will that work?

 

[sweetcell]

you're a natural at yeast starters - you discovered yeastcalculator on your own! it's a better site for multi-step starters - so use mrmalty to figure out cell count, then use yeastcalc for your multi-step.

if you have a 2 liter flask and you're doing intermittent shaking, it's best not to do a 2 liter step: the flask will be very full and it will be hard to get much movement in there. instead of 2 L and then 1 L, better to do 1.4 and then 1.5 (or whatever amounts are needed to get your cell count... but do two roughly even steps that allow for more shaking room in the flask).

let us know how it goes!

 

[mkyl428]

Awesome!!!! Thank you!!

 

[mkyl428]

Made the starter last night added just a pinch of yeast nutrient pitched the yeast around 11pm, and already had a good krausen when i woke up this morning around 7! I did a 1.6 liter wort,(160 grams DME) I wasn't thinking about the added volume from the yeast, and now it's at 2 liters oops! oh well...

Both jars the yeast was kept in and the gas escaping the flask smell pretty fruity so that's good! It's looking like i might have harvested my yeast correctly! There was a slight almost vegital smell from one of the jars when i dumped the yeast out but I'm thinking that might have just been some hop sludge that could have made it into the jar when i harvested the yeast...