Quick Yeast Washing Question

[lexuschris]

Hey all,

I was able to sneak a brewday in today!

About 2 months ago, I tried yeast washing for the 1st time and stored my little canning jars in the fridge since then. I decided to make a starter with one last night, and did my usual starter process.

So as I am batch sparging my brew, I checked on my stirplate, and the starter is a much darker color than usual at this point (med-brown). Granted there was a few ounces of previous wort with the yeast when I added it to the starter, but I am not seeing any krusen or other signs of activity. (usually, the wort turns really light cloudy color at 12-16 hours on the stirplate.

Is just a late start, since I'm starting with a smaller number of cells than a WL vial, and the yeast was asleep in fridge, etc.?

Should I pitch it and see if I get any fermenation within 72 hours? I have a packet of Safe-Ale 05 in the fridge as a backup...

Thoughts are appreciated!
--LexusChris

[jward]

I wouldn't expect much form 2 month old collected yeast. A tip from Tyler King was to put some fresh sterile wort on top when you store the yeast. You get higher viability rates. I have had the yeast start to go to town on the fresh wort before the cold slowed them down.

[brahn]

I agree with John. I'm sure there are still live yeast in there, just not as many as you want. When I've done something like this I would typically step the yeast up a few times before using it. I'd do 2-3 steps over about a week or 10 days to get up to a pitchable quantity.

[lexuschris]

Thanks for the info!

I decided to sprinkle the Safale US-05 on this wort, and just left my starter keep going on the stirplate to see if anything comes of it. It has started to change color some, so perhaps there was just a small number of viable yeast cells in my collected wash. I'll have to try the 'step up' process next time.

I usually use 1 vial of White Labs in a 1800ml starter, and am ready to go in 14-18 hours. Any recommends for size of the steps? 500ml, 1000ml, 18000ml ?

Thanks!
--LexusChris

p.s. had a picture of the starter I was trying to upload, but cannot seem to get it off my camera tonight...

[lexuschris]

yeah...got a realy nice krausen on the starter this morning...

Guess I might whip up a little hard cider or something for this..
--LexusChris

[brahn]

I would probably do 500ml, 1800ml and then 4000ml if you're doing 10 gallons or a high gravity beer.

[bwarbiany]

Screw starters. Use dry yeast

[tylking]

When I step up yeast from a slant it usually takes me a week to get a pitchable amount. I step it up by doubling the amount... 10ml, 20ml, 40ml, 80ml, pitching the previous starter into the fresh oxygenated wort at high krausen. As for storing yeast I will try and pull the best yeast possible from my fermenter, usually about mid-cone just after crashing it (cooling it down.) Once I know I have good yeast I will only store it for one week if it's slurry only. Yeast storage vessels should be breathable and cold, any carbon dioxide or oxygen in the mix is bad for the yeast - carbon dioxide being toxic and oxygen messing with the glycogen levels of the stored yeast. If I plan on storing yeast for up to a month I will put fresh cold wort in the storage vessel, it helps but it's not the best. I would never wash my yeast, I was always taught that if you need to wash your yeast (acid wash) you are doing something wrong in the cellar in the first place (think sanitation issues or selective cropping problems.) My guess is that you were just trying to clean the yeast of it's trub and not of any contamination but I would honestly just use fresh yeast whenever possible, yeast is making the beer and without good healthy yeast it's almost impossible to make a quality product.

[lexuschris]

Tyler, thank you for chiming in with some great details!

When I step up yeast from a slant it usually takes me a week to get a pitchable amount. I step it up by doubling the amount... 10ml, 20ml, 40ml, 80ml, pitching the previous starter into the fresh oxygenated wort at high krausen.

I saw a video on slanting, and it sounded cool. How long would a slant last in the fridge? Do you need breathable containers for that too?

... As for storing yeast I will try and pull the best yeast possible from my fermenter, usually about mid-cone just after crashing it (cooling it down.) Once I know I have good yeast I will only store it for one week if it's slurry only. Yeast storage vessels should be breathable and cold, any carbon dioxide or oxygen in the mix is bad for the yeast - carbon dioxide being toxic and oxygen messing with the glycogen levels of the stored yeast.

What is mid-cone? center of the fermenter?

...I would never wash my yeast, I was always taught that if you need to wash your yeast (acid wash) you are doing something wrong in the cellar in the first place (think sanitation issues or selective cropping problems.) My guess is that you were just trying to clean the yeast of it's trub and not of any contamination but I would honestly just use fresh yeast whenever possible, yeast is making the beer and without good healthy yeast it's almost impossible to make a quality product.

Yeah, I was just cleaning the yeast of the trub (again, saw a video about it on HBT) by adding sterile water to the yeast cake, swirling, letting sit for 20 minutes, and collecting a few small jars from the top. No acid, no infection, just trying out 're-using' yeast from a previous batch. Did not realize that more than a month would be detrimental. Good to know tho'!

By the way, my starter this morning has krausen almosting coming out of the top! So, it took a few days to get cranking .. but it is going strong now!

Thanks!
--LexusChris

[tylking]

The media you use will help determine how long a slant will last, most people will say every three months you should make a new mother slant - I keep mine for a year before I re-slant (mostly because I'm lazy!)

Mid-Cone: Yeast flocs at different rates and when serial re-pitching you don't want to select the yeast that flocs too early or too late. You want to harvest the yeast that has flocculated after fermentation has completed and as soon and cold as possible, in a conical fermenter this would be about the middle layer of the yeast slurry in the cone.

Yeast build up glycogen levels to survive towards the end of fermentation, as it ages it will use up this supply to keep alive. If you have a microscope or know of someone who does you can stain the yeast with Lugol's Stain (iodine 2% I believe) and determine its glycogen content - dark brown cells are rich in glycogen and pale yellow are low in glycogen. You would want to adjust your pitching rates due to the yeasts glycogen content.