Why do I need a 5L flask?

[DurtyChemist]

I walked into a local brew shop and saw they had one for $37. They're more expensive everywhere else. I don't brew 10 gallon batches but I'm setup for it with 10 gallon mash tun and an old Coors keg for a keggle. I know I can grow more yeast in a 5L flask and it might eventually pay for itself with savings but I'm currently doing fine with saving yeast from my 2L started and getting 3-4 starters from 1 pound of DME. Other than the money burning a hole in my pocket why would I need a 5L flask?

 

[jerbrew]

A 3L batch of beer?

 

[JonM]

Lager starters.

 

[LLBeanJ]

I bought mine for brewing lagers. Didn't need it for any other reason. After using it a few times, I found the physical size of the flask to be inconvenient, as it didn't really fit into the small fridge I use to crash my starters. After one of my 2L flasks broke, I replaced it with a 3L flask and now it's the only one I ever use. It works great for growing up yeast populations for both ales and lagers, as it's not too big and not too small. If you do decide to get a larger flask at some point, consider going with a 3L instead of a 5L. If I had to do it all over again, I would not have bought the 5L.

 

[m1k3]

I have a 5L but it never gets used. Dry yeast is much easier.

 

[tjosborne]

Two starters at once. I'll save 500 ml for a future starter and then I have enough to ferment two batches.

 

[IslandLizard]

As @LLBeanJ said, the 5 liter ones are kinda unwieldy. It wouldn't fit anywhere in my fridge to crash, unless I take a shelf (and stuff) out.

I use two 2 liter ones if I need a larger starter, or make the starter in a gallon jug. I also have a 3 gallon carboy...

 

[DurtyChemist]

I didn't think of it being too big to cold crash. I guess pitching an extra gallon of beer might change things without decanting. I might start shopping for a 3L. How many cells would you get from a 2L starter with fresh yeast?

 

[Murphys_Law]

I still use a 2L but will do a step starter if required. much easier to store!

 

[IslandLizard]

I didn't think of it being too big to cold crash. I guess pitching an extra gallon of beer might change things without decanting. I might start shopping for a 3L. How many cells would you get from a 2L starter with fresh yeast?

If I start out with a smack pack that's 2 months old (61% viability), and 1.6 liter of 1.037 starter wort, I'll get 288 billion cells. That's enough for a 5.5 gallon batch of 1.075 ale.
For a double batch or a lager the additional cell count is very easy to attain from there, with plenty to spare.

Even if the yeast is 4 months old, I still get around 280 billion cells with 1.7 liter.

I rarely fill my 2 liter flasks with more than 1.6-1.7 liter. I have a shaker, so pretty much any vessel will go, as long as I leave some headroom. I also use 1/2 gallon jugs and 1/2 gallon pickle jars (wide opening, easy to clean!).

 

[beernutz]

Lager or big ale starters for 10 gallon batches is my answer. I don't find that a 5L Erlinmeyer is hard to store--I just keep it in the box it was shipped in which is big enough to also hold my stir plate. The box sits on top of a storage shelf minding its own business and not taking up excessive space in my small storage room.

 

[IslandLizard]

Lager or big ale starters for 10 gallon batches is my answer. I don't find that a 5L Erlinmeyer is hard to store--I just keep it in the box it was shipped in which is big enough to also hold my stir plate. The box sits on top of a storage shelf minding its own business and not taking up excessive space in my small storage room.

Where do you cold crash it? In your fermentation fridge?

 

[lhommedieu]

I have a 2L and a 5L. I found that I never had problems with lager yeast using the 5 L flask for 10 Gal. brews; the 2 L flask proved a bit messier. Point's moot though: I switched over to dry yeast.

 

[beernutz]

Where do you cold crash it? In your fermentation fridge?

I'm lucky enough to have several places to cold crash including a fermentation chest freezer, wine storage upright freezer (no one else wanted it from my in-law's estate), and an extra refrigerator (a 20 old Kenmore we kept when we upgraded to an LG fridge about 6 years ago) that's in our garage. In a pinch I guess I could put it in on the shelf in my keezer but I've never tried that.

 

[d3track]

Need? Not a "need." Is it nice for high gravity brews, lagers, overbuilding? Very.

 

[brick_haus]

I use 5L flasks for my starters but I brew 1/2bbl batches, mostly 1.080 ales.

 

[schematix]

I have 5x2L flasks. Sometimes i wish i also had 2x5L so i when i was doing 4x1.5L i could do 2x3L or 2x4L. But 5L flasks are $$$, especially the good ones (the LHBS ones are crap quality). Real heavy duty Pyrex ones are twice the price.

View attachment ImageUploadedByHome Brew1483152279.117970.jpg

Don't need as many stir plates either

 

[atoughram]

If you get the larger 5L flask, make sure to get a larger stir bar too.

 

[JimRausch]

Here's my take: spend $37 on an E-flask and guaranteed it'll break 2 weeks later.
After breaking 2 in the space of 2 months, now I use qt. mason jars and 1 gallon jugs.

 

[Gavin C]

5L flask is useful for when you want to make a 3L or greater sized starter

Whether or not you feel a need for that depends on what pitch rate you feel is adequate for your beers.

That can depend on many factors, not least of which is a brewer's preference.

Other factors in play can include the type and size of the brew.

• Lagers
• High gravity brews
• Large batches (eg 10+gallons of ~1.05 ale)
• Combinations of some or all of the above

I use mine regularly. Storage is not an issue nor is chilling the starter after fermentation is completed.

5L flask fits in my regular counter depth fridge without problems. Sits right next to the milk till needed.

 

[m1k3]

Again... you don't need one. Brew a beer with one pack of yeast and then repitch. You get free beer and less labor.

I'll sell you my 5L.

 

[Gavin C]

If you get the larger 5L flask, make sure to get a larger stir bar too.

No need for that in my experience.

 

[day_trippr]

No need for that in my experience.

Mine either, but I also use the same bar magnet setup as Gavin's setup shows.

I use my 5L at least as often as my pair of 2L flasks, for missions where size matters...

Cheers!

 

[atoughram]

Looks like you've already got the 35mm bar.

I dont.

the 25mm bar will work at higher RPM

the 35mm bar works at lower RPM

 

[Gavin C]

Looks like you've already got the 35mm bar.

No. I just have the 25mm (1"bar pictured earlier). Works very well for my purposes.

Flask was $39 w/ free shipping FWIW. Solid and useful piece of kit.

 

[Queequeg]

Lager starters.

This, I bought one for lager and imperial styles.

You can use a smaller one with multiple steps but who want to do that

 

[mobilecabinworks]

I love my 5L flask. I can make any size starters I need (especially barley wines!) and I use it for extra wort when needed. My whole system is designed to expand to 10 gal batches with very minimal changes though.

 

[DurtyChemist]

I'm back to this debate since I just picked up a lager yeast locally from 11/3/16 and 54% viability. A flask would cost $40 and 2 lbs of grain would be about $3. For $43 I could make a 4L starter and have enough yeast to pitch into a 1.060 lager vs buying an additional $24 in yeast. It seems to pay for itself in two lagers.

 

[schematix]

Best investments in home brewing.... flasks+DME, and grain mills. They pay for themselves within a few uses.