Just found a box full of assorted test tubes, all about the same size. After a little research I believe them to be 10 mL, many Pyrex, and all look like relatively high quality, lab quality stuff (not like I'd really know I guess). I picked the box up because I thought it might be helpful in creating a yeast bank. What's the consensus?
Tons of Test Tubes
- Thread starter SenorPepe
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
bovineblitz
Well-Known Member
Are there caps?
SenorPepe
Well-Known Member
OK so I tried an experiment yesterday to determine the capacity of these things so I can try to find caps. I don't have any kind of reliable way to measure volume. I used plain old cold tap water and weighed it out at 34.8 grams. That would lead me to believe I have the 34 mL version, but does anyone know enough about this to tell me if it's plausible this measurement could be way off, since I did not control water temperature or purity. Or, all confounding factors aside, is it not likely to be off by more than a few mL?
SenorPepe
Well-Known Member
Awesome. Confirms what I was able to find online, which is spotty and all over the place. Know where I can get caps for these? They're rimless if it matters and for whatever reason I can't get the right search terms to find anything helpful.
SenorPepe
Well-Known Member
Hmm I never thought about it but am I going to have a problem storing frozen yeast in stoppered, rimless culture tubes? For some reason even though there is not threading on them I was imagining a more secure seal.
test tube stoppers arent really meant for being a robust, strong, mechanical seal.
they are meant to be a completely air-and-liquid-tight seal.
you shouldnt have a problem using them in the freezer unless you are rough with them and the stopper becomes dislodged. in a lab, you would use a product called Parafilm to mechanically seal the stopper onto the test tube if you needed mechanical stregnth to prevent the stopper from coming out. its like a very elastic rubber-ish tape almost. google it. its actually pretty handy stuff to have around.
they are meant to be a completely air-and-liquid-tight seal.
you shouldnt have a problem using them in the freezer unless you are rough with them and the stopper becomes dislodged. in a lab, you would use a product called Parafilm to mechanically seal the stopper onto the test tube if you needed mechanical stregnth to prevent the stopper from coming out. its like a very elastic rubber-ish tape almost. google it. its actually pretty handy stuff to have around.
SenorPepe
Well-Known Member
Aye aye. Man, love this forum. I don't know dick about lab stuff but it doesn't matter. Cheers.
EDIT: One last question--seems I can only find rubber stoppers. Some say not food grade. Does this matter? Can I boil them or should I just starsan?
EDIT: One last question--seems I can only find rubber stoppers. Some say not food grade. Does this matter? Can I boil them or should I just starsan?
realistically, for storing yeast samples, it shouldnt matter. the extremely small amount of anything that could come out of a stopper and reach the beer is not going to be enough to matter.
most stoppers are made from natural rubber, which is fairly non-toxic. if you find food grade ones, great. i wouldnt worry about it too much though.
most stoppers are made from natural rubber, which is fairly non-toxic. if you find food grade ones, great. i wouldnt worry about it too much though.
