Frozen Yeast Bank Tube Size...Is Bigger Better?

[CTS]

Hello,

I know I'm missing something here but why are frozen yeast banks kept in 15ml test tubes? Wouldn't it be better to make them in say a 50ml tube.

Wouldn't you need to do multiple step starters to get the cell count up in the 15ml tube compared to the 50ml one?

I want to just take a tube out make one large starter, chill, decant and pitch....is this unreasonable? or what am i missing?

Thanks!

 

[brownni5]

Despite the size, you're likely going to have to baby the yeast along after thawed - one step and then pitch hasn't happened in my experience.

While it doesn't die if frozen correctly, it ain't happy when you thaw it. A small, low gravity starter over a couple days gets it woken up enough to put into a bit lager starter, which can then go into a pitch-able sized starter. At least that's how I've done it.

 

[CTS]

Despite the size, you're likely going to have to baby the yeast along after thawed - one step and then pitch hasn't happened in my experience.

While it doesn't die if frozen correctly, it ain't happy when you thaw it. A small, low gravity starter over a couple days gets it woken up enough to put into a bit lager starter, which can then go into a pitch-able sized starter. At least that's how I've done it.

Hmmm, starting to wonder if the frozen yeast bank thing is for me anyways. I don't really brew that much in a year to warrant it anyways, just figure it would be something else good to start doing.

Thanks for the info!!

 

[brownni5]

I've got a couple strains frozen and have successfully brewed with them. For me, I don't think it's worth the effort. I don't have too much trouble reviving jars of yeast, even after several months. Long term, I find slants to be the better option.

 

[Brooothru]

I've got a couple strains frozen and have successfully brewed with them. For me, I don't think it's worth the effort. I don't have too much trouble reviving jars of yeast, even after several months. Long term, I find slants to be the better option.

How are slants easier to work with? You still have to do multiple steps to get a sufficient viable yeast count. I find it much easier to pour 10ml of fresh yeast into a 50ml test tube, top off with a 30%/70% glycol:distilled water mix, then freeze. I don't use freezing as a technique except for unusual or limited release strains.

For yeasts I use more often I either overbuild the 1st generation starter and save a pint jar full, or harvest directly from the conical dump port for 2nd or subsequent generations. In the beer fridge the samples will maintain sufficient viability to crank out a fresh 1~2 liter starter in a day, even after 10 months' storage. The frozen (and slants) samples take more time and TLC, but will last for years. I just find frozen easier to work with.

Brooo Brother

 

[brownni5]

How are slants easier to work with? You still have to do multiple steps to get a sufficient viable yeast count. I find it much easier to pour 10ml of fresh yeast into a 50ml test tube, top off with a 30%/70% glycol:distilled water mix, then freeze. I don't use freezing as a technique except for unusual or limited release strains.

For yeasts I use more often I either overbuild the 1st generation starter and save a pint jar full, or harvest directly from the conical dump port for 2nd or subsequent generations. In the beer fridge the samples will maintain sufficient viability to crank out a fresh 1~2 liter starter in a day, even after 10 months' storage. The frozen (and slants) samples take more time and TLC, but will last for years. I just find frozen easier to work with.

Brooo Brother

I didn't say easier, I said the better option, with the implication, "for me." In fact, I would say it's at least as difficult, but with more upside.

I find slants take up less space, and I can easily grab a little yeast from one and put it back into the fridge without preparing another frozen culture. That's the part I prefer.

 

[Brooothru]

I didn't say easier, I said the better option, with the implication, "for me." In fact, I would say it's at least as difficult, but with more upside.

I find slants take up less space, and I can easily grab a little yeast from one and put it back into the fridge without preparing another frozen culture. That's the part I prefer.

That's all true, and I conceed your point. It seems to me though that I start out with a much larger volume and subsequent number of yeast cells from a 10ml slurry than from a looped specimen on an agar slant, even after freezing for 3 or 4 years. It just seems like there must be more viable cells to propagate into a successful stepped starter that way. But either are certainly able to produce results.