I found I have an old 1 L Erlenmeyer flask (Pyrex). Any use for this in making starters? I’ve typically seen people talk about 2L+, so I’m a little doubtful. I don’t have a stirplate, I’m planning on shaking. Any thoughts on how much headspace I’d need to leave? Thanks!
For shaking I’d recommend a vessel about 4 times the size of the starter wort.
Your flask would work well for a 500 ml vitality starter the morning of brew day.
I have had a 1l and a 2l and with my 1l I have not had an issue with head space. 1 cup of water is 235ml plus however much yeast you put it, liquid may bring you to around 500ml. Just shaking the flask periodically, in my eyes, won’t be an issue for you. Even if you used a stir plate I don’t think headspace will be an issue.
The last time I used my 1l I built up a strain over a week and did not have head space issues.
My experience is that a 1L erlenmeyer flask weighs very near what a 2L erlenmeyer flask. Meaning…the 2L flask is around halve the glass thickness of a 1L and is just too fragile for me. If I’m making a “regular” strength beer I use the sturdy 1L flask (1qt to 1/2 Cup DME), but I’m making a “big beer starter” I use a 1 gallon glass jug that has solid wall thickness.
I have a one liter flask I bought. I’m not really sure why I didn’t buy larger. I think at the time it was all the store had. I still use it quite a bit because I mostly brew 1-2 gallon batches so I don’t need a huge starter.
I agree. When shaking a starter, it will foam up and overflow if your vessel isn’t at least 3 times the volume of your starter. I use a ~3L jug to make 1L starters and usually step up to 2L when needed.
There was a post on MTF from a microbiologist who said surface area was the key for the best growth and health in starters. He said most peoples flasks are too small and filled too full for proper oxygen for yeast growth. Ideally you should have no more than 800ml (less is better) in a 2L flask so a 1L is great to have around for a prop of of old yeast (maybe expired) that you have to step up. I just did one that was 200ml to start in a 2L flask and then for the second step to 2L it went in my big 5L flask. The 2L flask was a bit to big for the 200ml and the stir bar splashed a bit. The 1L would be great for that. Like I said, ideally a 1L maybe up to 400ml, 2L up to 800ml and a 5L up to max 2L
I have also found something <1000ml in a 2000ml flask to be the limit. Otherwise the vortex on the stir plate will not clear a space at the bottom – ie very insufficient aeration – or foam will rise too high and surface area be too small if shaking.
Thanks, I’ll keep an eye out for a larger flask. I’ll probably try for 3 L to be on the safe side.
I use a gal. glass jug. It only cost a few bucks and it came filled with apple juice. I’ve got 4 useless flasks of different sizes sitting in the garage now.
I think we’re starting to talk about two different things guys. He’s not using a stir plate, he said he’s going to shake-aerate. Mark the SNS yeast guru originally suggested a vessel 4 times the size of the starter wort and shaking till it’s all foam.
I prefer the lazy way of using O2. I use 2L flasks for about 1200-1300ml of wort. Works great.
The main idea though is that these SNS/O2 starters are not about cell count, it’s about pitching active yeast to your beer. So you build your starter about 8-12 hrs before pitching to your beer.
The rule is that the starter should be half the volume of the flask.
My procedure calls for boosting a White Labs packet to four 500 ml stock starters which I then refrigerate. Each 500 ml stock starter will be used to make a 2 liter starter for brew day. I use 1L flasks for the 500 ml stage.
Charlie
I hope this doesn’t take the thread too off topic… Have you considered using a 1/2 gal mason jar? They are thick and heat resistant.
For SNS starters, the rule is that the container should be 4x the starter size.
I haven’t, I don’t have a mason jar that big either. I suppose I could try a growler.
Go buy a gal. of apple juice and you’ll be set.