The limited release ends soon so I ordered 5 packs today, fresh from Odell. I'm going to make a starter with one pack just to grow it up for storage and use this 15% glycerine method. I'll report back next fall on how well it worked.
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What is your new favorite? I really need to look into how to freeze yeast2352
Long term storage, like year or yearsFor example, buy a pack of yeast, build a half dozen slants, divide up the pack slurry among the half dozen slants, freeze. Then when I need some just prop it up?
I'm no expert on this as I don't make yeast slants, but isn't the purpose of slants to step up or store tiny samples from a plate after isolating a pure culture? If you aren't isolating colonies from single cells from a streak, wouldn't it be simpler to store slurry under beer so that it remains anaerobic? I don't see any advantage in storing nonpurified yeast on agar, where it's exposed to air, rather than leaving it under beer. Except that slants take up less space than vials.
It sounds to me like you've got an article that's hybridizing slanting with freezing. I may be wrong here (wouldn't be the first time ) but slants are generally stored at refrigeration temperatures so that glycerin is not needed. Glycerin is used when freezing yeast to reduce the sharp-end crystalline structure such that it doesn't pierce the cell walls of the yeast - leaving them for dead upon thawing.Just what I was looking for. I appreciate you taking the time. Im going to give this a shot.
1. Rubbing alcohol (95%) will clean and sterilize a pipette.
2. If you're freezing, then probably eyeballing is sufficient as long as you're a good eye-baller . If you're slanting then you should only be piercing the slant with your innoculant so no eye-balling is necessary.
3. I've also read/heard that gelatin can work in place or agar for slanting and plates, but it's also my understanding that (basically) a lifetime supply of agar-agar can be bought for a few dollars so why not just make the initial purchase (amazon, asian market, health food store, etc).
4. Plates are for a different purpose. If you're not concerned with isolating individual colonies and propagating them up then I do not see the need to worry about plates. If you do happen to go the direction of agar slants with autoclave and the works then you may as well get some plates for playing with too. If nothing else, swab the inside of your mouth and plate it out - just for fun
5. USP Glycerine is food grade as long as there is no other ingredient but glycerine. I believe the USP is important.
6. Again, this seems like methods of freezing yeast. It sounds like you'd come out with an ~14% glycerine yeast slurry which is in the "ideal" range for glycerine to prevent cell death due to ice crystals. Freezing is the method I use since I am not concerned (read: haven't take the steps) with ensuring a 99.9% clean yeast stock. I propagate enough extra yeast from the initial vial/pouch purchase such that I can freeze a couple vials of yeast for future use, and it gives me one to use now. If I didn't repitch then I would have three uses per yeast purchase, but I almost always repitch a few times. I figure it works out to be about 7-10 pitches per yeast purchase on the low end most times.
As you can tell, I'm not overly familiar with slants, plating, and agar-agar related processing or isolating yeast colonies. One day probably, but not today.
Freezing is the method of choice for me. I'm able to maintain a large collection of yeast in my frosty (not frost-free) deep freeze at about -10 to -20F. I have found the method to be sufficient for my needs and low-tech enough that I can deal with it without creating a complete yeast lab experience. I recently used a white labs PC yeast (3726-PC) that had been frozen for 2.5 years. It took about 24 hours to "wake up" in the starter, and after that was done propagating in another 24 hours. The resulting beer tastes like what I expect to get from that strain so I call it a success. The biggest thing I have noticed in resuscitating frozen yeast is the variable "wake up" time which can be from 1-3 days. My experience has been that the quicker the "wake up" the more likely the yeast is to perform as expected. Those that took 3 days to "wake up" were less stellar fermentations than those that only took a day. I think an important key in ensuring that the samples have a good dormancy is how they are treated just prior to freezing. Quick propagation without letting them overspin (stirplate here), and then quick crash, and then directly into freezer has worked best for me and shown to give the best "wake up" times.
Edit: I should add that when pulling a frozen vial from the freezer for use I will have the starter it's going into all ready (boiled, cooled, aerated, etc). Then I'll quickly thaw the yeast in warm (100F) water until the slush has just melted (about 5 minutes). Then it's immediately pitched into the starter. It's my understanding that as soon as those yeast cells come out of dormancy they will start using their reserves causing even more stress. I've opted for this method and it has worked for me.
Still haven't found DMS even after switching to 60 min boil. Am I bold enough to do whirlpool hopping in pils malt beers? Heck no, that boogeyman is in there somewhere.I pronounce most of these correctly, but how do you pronounce Acetaldehyde and Diacetyl?The cool thing about acetaldehyde is that once you've learned what it is, you'll never find it in your beer again. Other than maybe one of my early attempts at a light colored beer, I've never had it. Sure spent a lot of time figuring out what it is and where it comes from though.
+1. I remember racking and kegging too soon back in the day and noticing it a time or two. Since I started giving yeast time to clean up, not once.
I pronounce most of these correctly, but how do you pronounce Acetaldehyde and Diacetyl?The cool thing about acetaldehyde is that once you've learned what it is, you'll never find it in your beer again. Other than maybe one of my early attempts at a light colored beer, I've never had it. Sure spent a lot of time figuring out what it is and where it comes from though.
Thats a good thing. Better than needing more.Please dont tell my wort that... lol. Ive done it all the way out to finished beer. It works. I was amazed at first but when you think about it, its about whats in the wort not the physical grain itself. The buffering we are working with is in the liquid.Yeah no problem. I haven't found using brunwater to be able to figure out adding acid directly to kettle works. For mash...no problem. So when I want to keep lactic to minimal, I throw all salts on mash strike water .then use 1ml at time in kettle.So far I have had good luck using the average of Kai's figure for adjusting with lactic 88% at .175ml per pound of grain bill per .1 of ph drop needed. So in a ten pound grain bill that needs to be dropped from 5.5 to 5, it would be 10x.175=1.75x5=8.75ml if you stick with .5ml per pound max thats 5ml obviously, so you could start by trying 5ml and see where it gets you. Then decide if that's close enough. Or switch to sulphoric 10% which requires about 1.75 per pound grain bill...
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but i think this only works in the mash. in the kettle its not the same buffering that occurs with the grain.
So I'm going to say no, it's not the same. I haven't been able to replicate predicted ph drop in bru'nwater for mash vs.whats happening in wort. It's taking less latic to drop wort ph vs ph in mash.
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I've noted a curious pH result in some mashes. The pH can vary by over 0.1 units during the course of a mash. Needless to say that this could be alarming when you are expecting a certain result. However, continued monitoring of the pH during my last several mashes have shown that the pH tends to come back to the targeted value by the end of the mash.That shouldn't be too much of a surprise since from mash in through to the kettle the composition of the wort is constantly changing. Seems like we could expect the ph to fluctuate a little. Fully agree with you on not chasing the ph around with salts and acid.
In addition, it seems that mash pH tends to self correct to a value closer to 5.4 when the pH is either higher or lower than that value. So my darker mashes in which I'm targeting a pH of 5.5 or more tend to drop their pH throughout the mashing period and paler mashes in which I'm targeting a pH of 5.3 or less tend to rise. The final result typically gets closer to around 5.4.
Interesting results that suggest that we should NOT be overly alarmed when a pH reading isn't exactly where you intended it to be. Don't go reaching for more acid or alkali when an early reading isn't where you want it, give it some more time.