Slanting yeast

kappclark said:

Can you get the slant's pre-filled instead of 'rolling your own' ??

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Yes you can Morebeer.com sells them but it kinda takes the fun out of the process. Also I think they are kinda pricey

Thx - checked that one out, and you are right -- rolling my own is really the right way..

This is a remarkable thread - right up there with Yeast washing illustrated..

Thank u for making the effort to explain this process..I am inspired !

So I made my first mini starter today and am a little worried about infection since I didn't use sterilized wort ( I just used boiled Dme ) my question is can I sterilize boiled Dme and if so what is the best process thanks

The theory I have read is sanitized v sterilized in sterile environment nothing is left living. ie even the spores of nasties are dead not just the living nasties. To do this you have to autoclave it, failing have access to a autoclave a pressure cooker is the next best thing. The increase atmospheric pressure inside the cooker raising the boiling point of water to around 250deg F, that kills everything. If you stick it in there and pressure cook the mini starter in the vessel you are going to use to make the mini starter.

If I'm going to be using the starter as soon as it cools I will use a E-flask with foil over the top otherwise I use canning/babyfood jars. Make sure you know how to can (pressure cook) before you try it (RTFM, or Read The F... Manual). There are plenty of sites that explain how to can various goods.

I bought my pressure cooker specifically for making yeast starters but since I'm hooked, I even can my homemade baby food for my 6month old!

Thanks for the quick response, and I think I will do that in the future. My next question is do I need to boil the Dme water mixture and then pressure cook or can I skip the boil step and just mix the Dme water and then pressure cook it? Thanks alot

I tried not boiling it first and although it will work the hot break will be collected into the bottom of the starter. If you are stepping up starters you end up with a lot of hot break collected with the yeast. Also it could boil over making the seal difficult to hold a vacuum (not that I have seen inside the Pressure cooker while it is going). I boil just to get the hot break out and then put it into the pressure cooker, you still get a little bit of sediment as I think a second hot break occurs due to the higher temps achieved but it is considerably less.

I always dunk the canned wort into sanitizer before opening as any wort on the outside of the jar around the lid could have things growing on it and then the vacuum of the canned wort would drag that straight into your sterile wort!

Once you get a system try saving the last part of the wort in the kettle. From my brew last night I got 1.5l from what looked like hot break and hop material. Just ran it through filter after filter and got enough to make my next batch of yeast for what normally goes down the drain!

Clem

I've made vials of pressure cooked wort. I keep them handy for when I want to grow up a slant. I just open the slant and pour the sterilized wort from the vial on top of the slant and let it sit for a few days with the cap loose.

I made a few vials of low gravity wort for when I'm starting out from a slant. After that initial innoculation from slant to vial, the step ups are pretty easy.

i just inoculated my first slants today,i was thinking i should note some stuff down so when i get a few more strains etc i have all the info in one place with dates ,generations,where used ones went etc, has anyone made any type of spreadsheet with this stuff on they'd be willing to share? i'll make one myself if not but i'm all for not reinventing the wheel where necessary!

Below is the spreadsheet I use to track yeast slants and hop inventory. I also put labels on each slant. One on top of the lid with the strain number and one on the side with the inoculation date and generation number.

http://db.tt/ESAq5CY

Jason

JasonInBTR said:

Below is the spreadsheet I use to track yeast slants and hop inventory. I also put labels on each slant. One on top of the lid with the strain number and one on the side with the inoculation date and generation number.

http://db.tt/ESAq5CY

Jason

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cheers

where is the best place to get the equipment ? (vials, flasks, beakers, plates etc)

Cynmar. Mentioned in the first couple of posts. Decent prices and fast shipping.

Thanks for the friendly reminder !

Big package came in today from Cynmar- flasks, beakers, vials, Agar , loop... thanks for the guide and link

yo Sacc! Great thread and many thanks.

quick question (sorry if I missed it). Wondering why you don't use sterile wort when mixing your agar? Only DME. Any reason? You obviously have it on hand (as do I).

thanks!

JR

Johnny9 said:

Wondering why you don't use sterile wort when mixing your agar? Only DME. Any reason?

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When you put the solution in the pressure canner and bring it up to 250 degrees, it gets sterilized. Therefore no point in using pre-sterile wort.

I got started with slanting yeasts about 6 weeks ago. I've used 2 slants so far and it has worked great. Here's the part of my brew blog where I documented what I did. I had to remake my slants after the first attempt when I put in too much agar and the slants were way too thick.
http://littleshedbrewery.wordpress.com/category/yeast-propagation/

pngaudioguy said:

When you put the solution in the pressure canner and bring it up to 250 degrees, it gets sterilized. Therefore no point in using pre-sterile wort.

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No. My question was (poorly asked), can I use wort instead of DME in preparing my slants?

If the answer is yes, then the follow up question would be: what is the formula for mixing that (vol of wort / grams of agar)?

Since posting, I read a few more links and it sounds like there are different desired properties for Media vs Starters. I suspect the answer I will get will have something to do with that. But it would sure be handy to simply use some extra wort that I have on hand instead of having to by DME (which I haven't in years).

thanks!

You can use wort, but just make sure to pressure cook it instead of using it "as is" from brew day since it was only boiled. As far as the amount of grams of agar I don't know. In case you know the % needed, 10mg/ml is 1%

Agreed. It must be canned / sterile wort!

OK - Stand back I am trying science!!!
Please check my math....

Using Sacc's recipe of:

-35g DME
-400mL water
-2.5g agar

I just need to figure out how to replace the DME/Water volumes above with an equialent strength wort (at 400 mL).

DME= 45 ppg
35g = 0.077lbs
400mL = 0.104 gallons

Thus: [(.077)45] / .104 = 33.3 ppg

So by my calculations, if I mix 400mL of 1.033 strength wort (canned/sterilize) with 2.5g of Agar, I am good to go...

comments? Corrections? Am I way off base????

Just do this: Take 400ml wort around 1.040 and mix with with 2.5 g agar and you should be fine. The % agar and O.G. of the wort does not need to be exact. Just something close that the yeast have nutrients to grow.

bigljd said:

I got started with slanting yeasts about 6 weeks ago. I've used 2 slants so far and it has worked great. Here's the part of my brew blog where I documented what I did. I had to remake my slants after the first attempt when I put in too much agar and the slants were way too thick.
http://littleshedbrewery.wordpress.com/category/yeast-propagation/

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Nice guide -- I have everything I need, except a pure yeast culture, so I will get at HBS Friday..I have plenty of yeast, just not any 100% pure stuff.

Perhaps I missed it in reading through the thread but is there a reason to not use a small amount of Hops? If you're doing a bacteria slant I could see the downside but for yeast I'd swear I read somewhere that a little AA can help prevent bacterial contamination. Am I just crazy here? I was planning on picking up a few of the hop cones from outside (I don't have enough this year to bother drying) and throw it into the mix but now I'm not so sure. On top of that, I was going to put a 1/4 tsp of random yeast that I'm not planning on using in addition to a little DAP for nutrient (pre-wort boil / pre-sterilization steps). Is there a negative here I might have overlooked to doing this for slants?

Also, does anyone happen to have the Fat Tire strain on slant per chance and willing to part with a sample? I'm not really clear on the legalities of such a thing as it's not actually beer or wine but I have zero problems either trading supplies for it or outright paying them for it if such a thing is legal. Right now I'm using 05 to make batches of Hophead's F.A.T. and I'm told the wyeast VSS that came out a few years ago works fabulously for this recipe.

On a sidenote, I too picked up the Agar at a local Oriental store (although I later saw it at publix). I'm using 1/2 pint jars as temporaries until my tubes come in as I have no plates. I'm trying to isolate yeast from Muscadines (as a combination of the yeast wrangling thread and this one) that produced good results in a beer last year til contamination (I think) made it kind of bleh after about 3mos.

The only problem I see with adding hops is that the hop oils negatively effect the yeast, as well as bacteria. I would not use any hops unless you are having problems with contamination, and really, if you can't keep it clean then maybe slanting is not where you should be focusing your energy.

For slanting you really want the healthiest yeast possible, and, though I am not an expert, that is probably not what you'll get using hops.

Well, I plated a sample from the skins of my grandfathers muscadines. When I was younger he did batches that finished just above 21 to 23% alcohol so I'm hoping to get lucky and snag some of the same but I'm prob not that fortunate. Wonder what they think of barley...

question about the vials/culture medium...how many times can it be used ?

After culturing on the slant, and transfering all the yeast to starter, can you re-use the culturing medium in the slant, or do you need to remove the agar/wort after each use.

I am assuming that the entire yeast colony is taken off the slant by mixing in small amount of wort, then shaking and adding to small 250ML starter.

You can't reuse the culture medium unless you were to sterilize it again and some are saying the agar doesn't reheat/melt well so that's out. Agar is super cheap tho and if your slant tubes or plates are autoclave-able you can sterilize them and make new plates.

Btw, I ran into a local guy who sterilized the medium along with a glass syringe and uses sterile plates with great results. Doesn't seem like it's harder to sterilize the slants as described here tho and seems far less likely to become contaminated that way.

Also IIRC earlier in the thread some were saying they were taking only a sample of the slant to inoculate and stepping up from there. Others were dissolving the slant and using the whole thing unless I misread.

Accidic said:

You can't reuse the culture medium unless you were to sterilize it again and some are saying the agar doesn't reheat/melt well so that's out. Agar is super cheap tho and if your slant tubes or plates are autoclave-able you can sterilize them and make new plates.

Btw, I ran into a local guy who sterilized the medium along with a glass syringe and uses sterile plates with great results. Doesn't seem like it's harder to sterilize the slants as described here tho and seems far less likely to become contaminated that way.

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Thanks - I figured that, but wanted to be sure...I do not know advantage of getting a few cultures from a slant, and making a starter from that ... I imagine it wld require an additional smaller starter to begin the stepping up process..

IIRC sacch said when using the entire slant he went 250 -> 1L but that was using the whole slant. I believe someone else said if you used just inoculation of a small amount you'd start smaller like 50 then step up from there... Course, I have put many brain cells to sleep since then.

Long time lurker of this site but first time posting. Probably not a normal first post thread but hey. Also Sorry if this was summed up earlier but i didn't read the entire thread. Can you use a Granite-Ware type canning pot instead of a pressure cooker? If so, how do you measure the psi?

No. You need a pressure cooker. They are built to withstand the pressure, if you pressurize a vessel not meant to be pressurized, you are creating a bomb.

If you are unsure if the container you are looking at is ment to hold pressure, then look on it. If there is not a pressure gauge or some marking that says what pressure it will hold (kegs), then back away.

That is exactly what I thought but was maybe just hoping for a cheaper solution since I already have old bk's that are really canning pots. Thanks for the advice.

NP. There is just really nothing that can substitute for a pressure cooker, nothing cheaper anyway. Repeated boil/microwave methods (mentioned earlier in this thread i believe) could be the exception to that, but you pay in wasted time and uncertain results IMHO.

They're also only about 30-40 bucks off Amazon shipped. More than a dollar sure, but you can cook dinner in a pinch in about 1/8th-1/6th the time so it's got SWMBO appeal.

Well besides the quick food the SWMBO won't care cause I also do all the cooking. Granted that makes it an even better present for myself!

Mine went supersonic cause I bought a 4qt stainless model today for $15 on clearance but it's 8 qt width and perfect for half pints and plates.

Plus it's convenient for dinner or at least that's what I told her....

i bought mine for yeast banking but actually use it more for chicken

We have a vegie garden and can tomatoes every year - I bought a large pressure cooker this year under the pretense that it would make canning easier and SWMBO agreed. My secret motive was for me to be able to can wort and slant yeast
I also bought a food saver this year so we could freeze individual packs of diced peppers from the garden to use in chili this winter - translated what that means is I have a way to vacuum seal next years hop harvest.