Questions about how to use Mr Malty with washed yeast and a starter

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jtkratzer

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I have 4 pint-sized baby food jars and a 150 ml baby food jar I filled when washing my last batch using WLP400.

I am planning on putting the slurry from two mason jars and the baby food jar into a 2L starter on the stir plate to reactivate it and build up the population. I wasn't planning on refrigerating and decanting the liquid, I was just going to pitch the entire starter. If it's good enough for John Palmer, it's good enough for me.

I'm just wondering how to use the calculator with yeast that was harvested on 3/5, washed, and stored in the fridge since then along with using a 2L starter.

Should I do 1 liter for 12-18 hours on the plate and then add another liter of wort or just do 2L right from the beginning?

Or should I get the 2L starter going first thing in the morning before work, put it on the stir plate, let it go until Thursday evening, chill, and then warm it up on Friday morning, decant and pitch when I brew on my day off on Friday?

Seems I'm trying to use two different versions of the calculator with pitching from slurry and using a starter at the same time.

Estimated OG is 1.055, harvest date was 3/5, and I don't have a measurement on the amount of slurry I have to start with. Any need to measure the amount of slurry I have in milliliters after decanting the liquid prior to pitching into the starter?
 
Personally, I wouldn't bother doing a starter with yeast that fresh. That said, you could estimate the amount of yeast you have (since it's been rinsed I'd go with about 2.5-3 billion cells per mL) and put an amount into the starter that will result in roughly doubling the population. Assuming this is a 5 gal batch, for your OG I'd start with ~30 mL (2 tbsp) of slurry, set your viability in MrMalty to 80-90%, and let it tell you how big a starter to make. On a stir plate, that's ~900 mL.
 
What I do is chill and crash the yeast in the jar. When it's all at the bottom, I take a volume measure of it and treat that sediment like high-density yeast (thick slurry, 4.5 million cells per mL). If I've got enough cells in jars, I won't bother with a starter (although I *do* wake up the cells with a little wort ahead of time, either some thin DME wort or stuff from the second runnings of my mash, so the yeast is bubbling nicely when I pitch it).

If I don't have enough cells in jars, I estimate how many billion cells I have (100 mL at 4.5 billion per mL is 450 billion cells), and convert that into percentage viability (45% viable in the example) and pretend I have a liquid yeast vial with that viability.

So, if I have 150 mL of yeast at 4.5 billion/mL from 3/5, which mr malty tells me will be 78% viable today (3/15), I'd have 150 * 4.5 * .78 = 526 billion cells. If I needed 750 billion cells (a big batch of lager, say), I'd tell it that I had a 526% viable vial.

If you're pitching a smaller volume of yeast or don't want to crash the yeast down to a moderately-compact layer, you might need to invest in a microscope and a hemocytometer to do an actual cell count. I feel like i can get away with my technique because I have a fairly thick slurry. It's still an estimate though, especially since I'm eyeballing the non-yeast solids as well. My technique seems to work pretty well, I've been using it for a while now with reasonable success.

The basic strategy though, is if you know how many cells you have you can just manually set the viability percentage to be that many billions, since 100 billion in the vial is 100% viability and the calculator lets you go above 100% viability (and still works when you do).
 
Oh, the other reason I'd suggest decanting is just because you've got 2L of extraneous liquid going into your beer. That's what, 10% of a 5 gal fermentation? If there's any funk in that stuff, you'll notice. I especially do that when I make a big starter, since I tend to push my starters at warmer temps, since I don't care what the starter wort beer tastes like.
 
I'm definitely planning on a starter simply because this is my first attempt at washing yeast and I want to ensure my sanitation practices are where they need to be before dumping nasty yeast into 5 gallons of wort.

I'll make a starter tonight and put it in the stir plate for 24-30 hours, refrigerate, then warm up to room temp, decant, and pitch whatever slurry I need after spending more time on Mr. Malty and HBT.

IF the beer I decant is nasty, I'll go buy a vile of WLP400, make a starter, and brew Saturday instead.

Without having my 2L flask in front of me, I'm wondering if it's feasible to mark off 100ml lines to judge the yeast line after letting it settle out.
 
Alright...home from work. Got 2 of the pint mason jars out and the one baby food jar. I put empties of the same size next to them and filled each with water to match the line of the yeast cake. Added the three jars of water together and came up with about 57 ml of yeast cake.

Using the Mr. Malty calculator for pitching from slurry and defaults of 2.4 for thickness, 15% non-yeast solids (this yeast was rinsed with cooled, boiled water, not washed with an acid solution), OG of 1.055, 5 gallons total, and harvest date of 3/5/11.

The calculator comes up with 106 ml of slurry. I don't have that much between all the jars I have and I want to make a starter to check my sanitation practices. I'm guess I don't need a 2L starter to double that small of an amount of yeast.

Does a 1L stater on the stir plate for about 24 hours and then refrigerated for say 18 hours to let everything settle out, decant, warm up to pitching temp, and pitching seem like it should work out alright?
 
IME, 18 hours won't be enough tiem to crash the yeast out, and 24 hours may not be enough for it to ferment fully. I'd just leave it on the stir plate the entire time and pitch directly. A liter of starter beer isn't ideal, but on your timeline I think it's the best option.

I think you have enough slurry to pitch, personally. If the yeast has been in the fridge for two weeks, it's probably compacted to at least 4 billion/mL, in which case MrMalty says you need ~75 mL. Two days on a stir plate won't give you a sanitation check anyway; that isn't nearly enough time for a bacterial culture to become obvious without a microscope.
 
a10t2 said:
IME, 18 hours won't be enough tiem to crash the yeast out, and 24 hours may not be enough for it to ferment fully. I'd just leave it on the stir plate the entire time and pitch directly. A liter of starter beer isn't ideal, but on your timeline I think it's the best option.

I think you have enough slurry to pitch, personally. If the yeast has been in the fridge for two weeks, it's probably compacted to at least 4 billion/mL, in which case MrMalty says you need ~75 mL. Two days on a stir plate won't give you a sanitation check anyway; that isn't nearly enough time for a bacterial culture to become obvious without a microscope.

Well, I don't have to brew on Friday. I can brew Sunday if that's enough time. If the yeast will drop out in the fridge over night when washing, why won't it work with a starter? 2 days on the plate to ferment out puts me at Friday evening, crash till Sunday morning, warm up and pitch. Is that sufficient time? This is my first rodeo with a stir plate and washed yeast.
 
Sorry if this is a dumb question (I am new at washing and making a starter). My timeline is even tighter than yours... So my question is why do you need to "crash" the yeast first?
 
BeerBrods22 said:
Sorry if this is a dumb question (I am new at washing and making a starter). My timeline is even tighter than yours... So my question is why do you need to "crash" the yeast first?

I was planning on refrigerating the yeast after it fermented the starter to get the yeast to drop out of suspension. Then I can dump the beer and only pitch the yeast into the new batch of wort. A 2L starter is about half of a gallon. Will half of a gallon of fermented beer that didn't have the same grain bill, fermentation temps, no hops, etc impact the flavor of the 5 gallon batch? I don't know.
 
Here are two pictures, one right getting it spun up and 7 hours later:

image-1707590148.jpg


image-992719753.jpg
 
that was a good idea to measure the ml of yeast with water in an identical jar. I always just eyeball it, but I may have to steal your idea.
 
You could use half-pint sized mason jars. They have mL markings on them that are 50mL apart but still easy enough to eyeball it from there.

I think you start running into how much yeast can you actually get to settle out of a 1/2 pint jar? How many of those half pint jars do you need to pitch into a starter or how many times do you have to step up your starter to get the yeast count you want/need?

My 1 pint jars had an average of about 25 ml of yeast slurry...not a lot.

Here are some pictures of my starter using a stir plate for the first time:
Just after pitching last night and getting it going:
Starter.jpg


8 hours:
photo2.jpg


14 hours:
photo3.jpg


15 hours:
photo4.jpg



Looks like it's working just fine. Not sure if I should have done it or not, but it's already done...just gave it a swirl to bring all that yeast back down into the liquid so it doesn't dry and go to waste on the side of the flask.
 
I think you start running into how much yeast can you actually get to settle out of a 1/2 pint jar? How many of those half pint jars do you need to pitch into a starter or how many times do you have to step up your starter to get the yeast count you want/need?

My 1 pint jars had an average of about 25 ml of yeast slurry...not a lot.
How much yeast is in a smackpack or vial?;) We make starters from them all the time.

Getting at least 25mL in them is no problem. You can always wash the yeast with your boiled/cooled water, pour that into your gallon container, let that settle, decant most of the clear liquid, then slosh the remaining slurry and pour that into the jars. I have gotten over 100mL in them doing that.
 
How much yeast is in a smackpack or vial?;) We make starters from them all the time.

Getting at least 25mL in them is no problem. You can always wash the yeast with your boiled/cooled water, pour that into your gallon container, let that settle, decant most of the clear liquid, then slosh the remaining slurry and pour that into the jars. I have gotten over 100mL in them doing that.

Awesome. This was my first time washing them. There's a huge difference between 25ml of rinsed yeast slurry that's already been brewed on, has trub, hop material, etc in it and stored in boiled water compared to perfectly sterile processes with fresh, healthy, well fed and rested yeast in a fresh vile or smack pack right from the lab.

I'm interested to see how thick the slurry layer is in this starter after pitching about 55 ml of rinsed slurry from 3/5/11 and giving it a few days on the stir plate.
 
Seems the process is working out. I had a layer of krausen completely covering the surface in under 5 hours after pitching yesterday. The yeast are having a good time in the carboy and the scent is amazing.

As soon as I pulled the flask off the starter, I got another 1L starter going in a 1/2 gallon jug with a vial of WLP029 for a Kölsch I'm going to brew this week. Time to get a second propane tank as this one is getting low.
 
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