Nightbiker said:Thanks! I'll give 'em a look-see. I'm assuming that borosilicate glass (it says that the cap is even autoclavable -which is excellent) is also freezer safe?
Yes...
Nightbiker said:Thanks! I'll give 'em a look-see. I'm assuming that borosilicate glass (it says that the cap is even autoclavable -which is excellent) is also freezer safe?
Uhm, I know I missed it, but where are you getting those vials? I'd love to have a batch of them -would really prefer larger ones (16 is such a small amount) -I've BEEN using sterile sample containers like we use in the hospital (110ml). I've never tried to harvest from a commercial bottle -and didn't know Bells bottle-conditioned. I love their brown ale -had it out of state once. Will have to see if I can find it and harvest some.
-thanks. Those vials look GREAT (love the tan look of yeast!)
postal_penguin said:Try out these: Video Link: http://www.amazon.com/gp/product/B005Z4QSOS/ref=oh_o01_s00_i00_details
15mL conical centrifuge tubes pack of 100 for $16. They are autoclavable and can handle -80C temps fine, I use them in the lab all the time. If you really want you can wash and re-use them.
Try out these: http://www.amazon.com/gp/product/B005Z4QSOS/ref=oh_o01_s00_i00_details
15mL conical centrifuge tubes pack of 100 for $16. They are autoclavable and can handle -80C temps fine, I use them in the lab all the time. If you really want you can wash and re-use them.
liebertron said:I'm not sure why people freeze the yeast. The liquid yeast isn't frozen when you get it and has a shelf life of a few months. Seems like with some planning you could just use one strain of yeast for several beers in a row within a couple of months...? Are people saving the yeast for long periods of time?
bja said:What kind of gasket is used in the caps?
I get mine here: http://www.cynmar.com/ProductDetail/11527908_Clear-Glass-Vials-Wautoclavable-Cap-16ml--12pk they are completely reusable and autoclavable including the caps.
I thought about using those, but I've seen a lot of those plastic centrifuge tubes melt or deform in an autoclave.
I've never seen those tubes melt. They go through the autoclave at my work fine which runs at a higher temperature than my pressure cooker can attain. Just make sure to not screw them tightly or they will explode or collapse during cooling.
I should clarify, I have seen the 50 mL disposable centrifuge tubes melt a bit in a lab autoclave....since then I assume they might all melt. It wasn't exploded or crushed, the part of the tube above the liquid inside was melted and sloughed to one side.
I have some here at work that are 15mL...I'll throw some in my pressure canner and see if they make it through.
postal_penguin said:Also, do you have problems with the vials cracking if you fill them all the way up and then freeze? Seems the ice would expand and break the glass.
Nightbiker said:never had a problem getting my yeast back into suspension.
bjohnson29 said:I notice that after a day or two in the freezer, that my samples begin to separate (30% glycerin, 60% yeast, 10% headspace)...this normal?
mthompson said:Normal. The glycerin probably won't freeze, so separation is inevitable. The yeast will already be dormant as long as you store them in the fridge for a day or two before putting them in the freezer.
ekjohns said:If this is the case you have a problem. Glycerol is used to cryoprotect the yeast so if your glycerol is not mixed homogeneously then the cells are not protected. Are you sure it is not just liquid that became visible when the yeast started settling?
Freezing point of 30% glycerol is -9.5C so your tube should be frozen. Check your freezer cause it may be too warm (assuming the addition of yeast and wort does not raise the freezing point... science is a fickle b1tch).
% glycerol by volume / freezing temp (C)
10% -1.6C
20% -4.8C
30% -9.5C
40% -15.5C
50% -22C
60% -36.6C
70% -37.8C
80% -19.2C
90% -1.6C
100% 17C
I use .25 ml glycerol and add 1 ml of my yeast starter at high krausen. This cuts glycerol to about 20%. Store in my deep freeze at about 5°F. Have never had a problem with resurrecting any of my vials. Just followed advice of a grad student workin on yeast.
ul = microliter, 1ul = 0.001ml
FYI, you can buy glycerin locally. I don't bank anymore (not pure yeast, anyway) but I used to get glycerin at Walmart, in the pharma aisles. I probably posted this info about 100 pages back in this thread, but thought I'd throw it out there again.
Enter your email address to join: