If you submitted it for a membership we can't see it, it's hidden.
Do you know if its ok to upload it here as well, or does that make it a moot point for him to post it in the technical articles section?
If you submitted it for a membership we can't see it, it's hidden.
Brewitt said:Would anyone be offended if I consolidated the information gleaned from this thread and wrote up a Tutorial to post on the site. I think we have a critical mass of information that should be summarized. Credit where credit is due, of course. One of us should definitely do it.
WortMonger said:If you would like too, I can put your write up in the wiki. I have done a few wiki articles myself.
What are people mixing the glycerol with to freeze? I used fresh wort because I was worried about osmotic stress, but it was a pain because the yeast was making CO2 when they warmed up and made things very messy. I actually had a yeast bomb go off in my apartment!!! What a disaster!
Will putting yeast in straight water be bad for viability? I know with mammalian cells they'll all die instantly in water.
So thanks to your links I found out those white lab tubes are called baby soda bottles, which opened up a ton of links to buy them.
It looks to me that these are thin walled polycarbonate tubes. That is not really a problem but they certainly won't have the durability of White Labs tubes which are very thick walled. They are about the same diameter and hold only 40 mls. They may have problems during freezing and thawing but that remains to be seen. I believe you would be better off with the centrifuge tubes which are quite durable and close tightly.
Does anyone know differently?
The tubes I linked to are THICK walled (along the lines of those from White Labs)... These also close VERY tightly. I have a couple of packages of them on hand, so it was easy to check.
Brewitt said:Point taken. I apologize for misleading and misinterpreting. I saw people saing in reviews that these were like miniature soda bottles. Sound like I was wrong and that these are like the the clear 40 ml polycarbonate tubes we use in laboratories.
They ARE miniature soda bottles, though possibly not in the sense you're thinking. They are called preforms, and are typically used by the bottling facility by expanding them to full size by heating them and blowing air into them (an effect that resembles glass blowing). They are exactly what White Labs uses, and ARE fairly thick-walled because they contain enough material to make a typical 2L bottle... the walls get thinner as air is blown into them to "stretch" to full-size.
They are popular because they are already manufactured on a massive scale for the beverage industry, making them a very cheap (literally pennies when bought in bulk) alternative to purpose-made labware. Notice how the caps are *identical* to soda bottles? It's not a coincidence.
What's the consensus on the best way scale up cultures? Should I just add fresh wort to the culture, or is it better to let the yeast drop out and dump the supernatant first? I feel like it's better to drop the yeast and dump the supernatant, but if so, is it best to put it in the fridge or leave at room temp? I wish there was a faster way that didn't involve centrifugation.
It seems like you'd definitely want to dump the supernatant from the starter before pitching to make actual beer, especially if the starter volume is quite large.
My article on Freezing Yeast has been approved and posted:
https://www.homebrewtalk.com/entries/freezing-yeast.html
Hope you like it and, if you have comments, please make them. I presume I can make edits at a later date or at least post changes and updates in the comments.
Very nice write-up. Thanks for spending the time and effort!
I've only done the freezing once, but I was surprised to read that you can get 100 billion cells to fit into a volume of 25ml. When I centrifuged my slurry to pellet the cells, 30 billion took up 15 ml. I would've guessed 100 billion would take up almost the entire 50 ml tube. Please correct me if I'm wrong.
That all said, if one uses the cells to inoculate a starter, I think it is a moot point. An overnight starter should give you about a 10X increase in cell number which way exceeds the necessary cell number for a 5-10 gallon batch.
I just assume about 1-2x10e8/ml as max density when brewing.
BBL_Brewer said:I finally got a chance to look at the article. Good summary. Nice job Brewitt.
Thanks. I appreciate the feedback. Especially from the originator of the thread. By the way, I did get promoted to Premium but what do I do with it. I'm not too interested in arguing with folks in the debate forums ;-)
BBL_Brewer said:Brewitt / Forkhead,
How are you mixing your glycerine solution? % v/v or w/v. The reason I ask is becasue v/v is a higher concentration than w/v. I'm ready to freeze up a bunch of jars of pacman and was contemplating how much glycerine to use. I already have a couple sterile jars of 60% and 50% w/v solution. I'm going to dilute them and was wondering what you guys have been doing.
How do I sanitize the glycerine solution without a pressure cooker
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