[KilroyWasHere]

Hi all,
I've tried SNS starters several times with mixed results. The one thing that stands our to me is that I can never get my 1 gallon glass jug completely filled with foam, and give up shaking after about 15 minutes, or if I feel like I am going to pass out  . I've given it a PBW soak and sanitize. What could be knocking down the foam, or preventing it from filling the jug?
Thanks in advance.

[denny]

Hi all,
I've tried SNS starters several times with mixed results. The one thing that stands our to me is that I can never get my 1 gallon glass jug completely filled with foam, and give up shaking after about 15 minutes, or if I feel like I am going to pass out  . I've given it a PBW soak and sanitize. What could be knocking down the foam, or preventing it from filling the jug?
Thanks in advance.

Hard to say. FWIW, I often don't get the entire container filled with foam and it still works fine. I feel like it's a case of close enough is good enough.

[fredthecat]

i shake for way less than 15 minutes. honestkly just about 60 seconds. currently the yeast packets im adding claim 180 billion cells per pack and they suggest just adding it to the wort directly. You might consider what yeast brand (ie. white labs old style liquid packs claiming a range of 60 to 120 billion cells per pack) as a factor if you're having issues with SNS.

though it sounds like you're mainly concerned about the foam. SNS is very much RDWHAHB

[KilroyWasHere]

Thanks guys, I try not to take 'filled with foam' too literally but I can't seem to get more than 50%. Enough of a difference from 'filled' that it makes me wonder.

[Richard]

I shake the wort before adding the yeast, and shake about a minute or until ~75% of the liquid has turned to foam. That doesn't fill the container much more than halfway. I let it sit a few minutes, then do it again, then I add the  yeast. My experience has been that you get less foam after adding the yeast. It seems that something in the yeast pack interferes a bit with foam development and retention.

[denny]

i shake for way less than 15 minutes. honestkly just about 60 seconds. currently the yeast packets im adding claim 180 billion cells per pack and they suggest just adding it to the wort directly. You might consider what yeast brand (ie. white labs old style liquid packs claiming a range of 60 to 120 billion cells per pack) as a factor if you're having issues with SNS.

though it sounds like you're mainly concerned about the foam. SNS is very much RDWHAHB

Cell counts can be a distraction. I've found that healthy, active yeast is much more important.

[fredthecat]

i shake for way less than 15 minutes. honestkly just about 60 seconds. currently the yeast packets im adding claim 180 billion cells per pack and they suggest just adding it to the wort directly. You might consider what yeast brand (ie. white labs old style liquid packs claiming a range of 60 to 120 billion cells per pack) as a factor if you're having issues with SNS.

though it sounds like you're mainly concerned about the foam. SNS is very much RDWHAHB

Cell counts can be a distraction. I've found that healthy, active yeast is much more important.

yes, i say cell counts but in practice i honestly just think of it as slurry in regards to harvesting and have almost never tried calculating cell counts. i then define it by
-age: old/stored, had sat for a week to 3 weeks, or sat under a week after harvesting (fresh)
-volume: storage sample in the fridge ~50-75ml, 250ml, or 500 ml etc etc.

[KilroyWasHere]

My concern about the amount of foam is driven by the assumption that it is representative of the amount of oxygen dissolved in the wort. Assuming that the dissolved oxygen is the real goal in shaking, maybe my assumption about foam representing that quantity is flawed. In the end we just want to dissolve as much oxygen as the 3 quarts of air in the jug can provide, yes?

[CounterPressure]

My concern about the amount of foam is driven by the assumption that it is representative of the amount of oxygen dissolved in the wort. Assuming that the dissolved oxygen is the real goal in shaking, maybe my assumption about foam representing that quantity is flawed. In the end we just want to dissolve as much oxygen as the 3 quarts of air in the jug can provide, yes?

Opinions vary...  here is mine, $0.00

My theory is the shaking distributes the yeast in the wort very well and that is pretty much the limit of its value. I do not think the foam is introducing any more oxygen to the wort than was already in it before you started shaking. I say this having not even tried an SNS starter yet, but I can see why people would prefer this method and I have no doubt that it works just as well as any other.

Pure Oxygen dissolves into a liquid at a pretty good clip. Pretty much about as fast as you can provide surface area, it's absorbed to saturation. I'm not sure if the mechanics of it are entirely the same when we are talking about oxygen in the atmosphere, but given the fact that you can pour your perfectly good beer onto a plate and take a sip within 2 seconds and it's already oxidized and horrible, I'd say it still happens pretty fast.

If you want to know how much oxygen is indeed being absorbed by the wort, put it in your container and seal it with a lid that has an access hole for a blow off tube. Obviously a tight fitting one with no leaks. Add the tube and run the other end into a bucket of starsan. Now shake to your heart's content. The amount of oxygen dissolved into the liquid is precisely the amount of liquid pulled up the blow off tube into the wort. If you shake the first time and you are not scrambling to get that blow off tube out of the bucket before the starsan gets into your wort, then that should be telling you there isn't much oxygen being introduced by the foam. My guess is it's already in there from the time you allowed it to cool.

[Richard]

When I make wort for a starter I boil it and put it hot into canning jars. Sometimes I even pressure can it, sometimes I seal it and put it in the fridge. In either case, I don't think there is much dissolved oxygen in the wort in those jars. I agree that saturation will be reached easily, and shaking to generate foam, with an enormous surface area, will help you reach saturation rapidly. That's why I only shake for a minute or so. After adding the yeast the little guys will take up the oxygen rapidly, so shaking again some time later will saturate the wort again and provide them with even more. If you worry that shaking or agitating the yeast again will injure them, then you can skip that and assume that the initial oxygen charge was adequate.

[denny]

My concern about the amount of foam is driven by the assumption that it is representative of the amount of oxygen dissolved in the wort. Assuming that the dissolved oxygen is the real goal in shaking, maybe my assumption about foam representing that quantity is flawed. In the end we just want to dissolve as much oxygen as the 3 quarts of air in the jug can provide, yes?

Absolutely correct IMO.

[Kevin]

If I remember Mark Van Ditta's original articles on the SNS method I don't believe he said the vessel had to be completely filled by foam. I seem to remember 50% which is what I've always aimed for. I can get that by shaking for far less that 15 minutes... more like 3 to 5 max.

[Richard]

Yes, look at the photos at: https://www.experimentalbrew.com/blogs/saccharomyces/shaken-not-stirred-stir-plate-myth-buster

I use a bottle like this, which is lightweight, shatterproof, sanitizable and has a handle built in. https://www.amazon.com/gp/product/B005P0NPKM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

[Kevin]

The handle would certainly help. I have a glass gallon jug that was sold with wine in it.

[denny]

If I remember Mark Van Ditta's original articles on the SNS method I don't believe he said the vessel had to be completely filled by foam. I seem to remember 50% which is what I've always aimed for. I can get that by shaking for far less that 15 minutes... more like 3 to 5 max.

Yes, he did say to completely fill it with foam.