Theoretical differences between a starter and a normal fermentation. Why not make the yeast starter just like a baby beer?

[iandanielursino]

Other than the amount of yeast and wort and that you pitch the starter at high krausen instead of letting it rip what differences are there between starters and normal fermentation?

I'm curious if there would be any issues with making a little baby fermenter, like say out of a 6" long 4" TC extension, and oxygenating it with a carb stone, and not agitating it. If that's what is good for beer wort why is it not good for yeast starter?

 

[lumpher]

Some people make low-alcohol beers and step them up as they go. For example, you could make a Tafelbier, then an ESB, then a Barleywine. The "agitating" part is because the yeast is growing exponentially in the starter and gulping the oxygen so fast the agitation is needed to help the yeast get all it needs.

 

[iandanielursino]

You mean pitching the yeast cake? I suppose that's a yeast starter in a sense.

 

[lumpher]

Yep, use the Tafelbier as a starter, then just pitch consecutively stronger beers on top of the cake. That's a "cheater" starter where you get to drink it too.

 

[iandanielursino]

I'm starting to be won over by the "shaken not stirred" method honestly.

It seems since the vessel is so large and you don't have to aerate after the pitch so AFAIK you can leave the cap on and not keep it exposed like if you used the classic flask and stir plate method. Still seems like since I have an oxygen kit why not use it on starters? I'm imagining some kind of like pressure-capable half gallon tank with a built in stirring mechanism and a port for a carb stone. Which is why I made this thread, what I'm wondering is, if you were to oxygenate the wort with pure oxygen, would it then need to be agitated? What would perform better, agitated or pure oxygenated but still?

I think what I'll probably do when I start trying to propagate yeast is make a batch of plain weak wort and pressure can it in pint jars and just shake them in a 1 gallon glass jug.

I don't have a pressure canner yet though, I just have a gigantic pot to water bath can half gallons of grape juice.

 

[HighVoltageMan!]

Agitation does a number of things. First it adds a small constant supply of oxygen which promotes lipid production needed for cell wall production. Second it helps to degas co2 out of solution to promote yeast growth. As co2 builds in the beer, it inhibits yeast growth. Third and likely less important, it keeps yeast in suspension so it’s mixed with nutrients.

Adding a big dose of oxygen at the start is good idea, IMO. But as the yeast ferments the wort, the co2 builds up and the oxygen is depleted. Agitation keeps the co2 down and the oxygen levels up.

SNS works because the yeast is pitch at high krausen. You can reduce the amount of yeast counts if it’s pitched in a high metabolic state. You could do the same with a stir plate.

I actually give the yeast a big dose of oxygen at the beginning of the starter and put it on a stir plate. I also crash the starter (if I want to decant it) before the starter hits terminal gravity. Lag times are reduced by half even with lower cell counts.

If SNS works for you, then use that method. But some say it’s superior to stir plate, that’s is a stretch. Different methods, both with good results.

 

[iandanielursino]

SNS works because the yeast is pitch at high krausen.

I've heard this a lot and I'm not sure exactly what this is referring to. The pitch into the starter or the pitch of the starter into a batch of beer wort? Can't you pitch whenever you like regardless of how the starter was prepared?

What kind of apparatus do you use to oxygenate before putting it in the stir plate?

 

[day_trippr]

I actually give the yeast a big dose of oxygen at the beginning of the starter and put it on a stir plate.

I do the same with straight O2 through a flow meter, pretty much for the same reason (I have it so why not use it?).

Cheers!

 

[HighVoltageMan!]

I've heard this a lot and I'm not sure exactly what this is referring to. The pitch into the starter or the pitch of the starter into a batch of beer wort? Can't you pitch whenever you like regardless of how the starter was prepared?

What kind of apparatus do you use to oxygenate before putting it in the stir plate?

The pitch of the starter at high krausen into wort.

English brewers would skim the top of the krausen of an active fermenting beer and pitch it into another batch. The yeast is in a very active state and starts very fast.

I just use a vinyl hose and a diffusion stone and inject pure oxygen into the starter for 90-120 seconds.

 

[CascadesBrewer]

Other than the amount of yeast and wort and that you pitch the starter at high krausen instead of letting it rip what differences are there between starters and normal fermentation?

I am not 100% sure what you are proposing. There is a lot of overlap between fermenting beer and different types of starters, but there are differences. The goal of a starter is to provided an environment where the yeast can build up their cell structure and multiply (low gravity, agitation, oxygen, warm temps, etc.). When fermenting a beer, the goal is to produce the flavors and alcohol that we desire in a beer (high pitch rate, pitch healthy yeast, temperature control, etc.).

SNS starters (or other versions of vitality starters) work well when you are starting with a decent cell count and you want to make sure the yeast are healthy and active (say a 100B cell pack of Wyeast into 5.5 gals of 1.050 wort). A larger starter on a stir plate is a better way to build up cell counts (say to build that 100B cell pack up to 400B cells to pitch into a larger batch, high gravity beer, or a cold fermented lager).

 

[iandanielursino]

So sounds like you still need to agitate even if you oxygenate. That kills my baby fermenter idea. The version with a mechanical stirring mechanism might be viable, but I don't know of a cheap 1.5" TC pressure capable stirring device.

The pitch of the starter at high krausen into wort.

I'm still missing why SNS is pitched at high krausen and stir plate flask starters are not.

 

[HighVoltageMan!]

So sounds like you still need to agitate even if you oxygenate. That kills my baby fermenter idea. The version with a mechanical stirring mechanism might be viable, but I don't know of a cheap 1.5" TC pressure capable stirring device.


I'm still missing why SNS is pitched at high krausen and stir plate flask starters are not.

Proponents of SNS say it's superior to stir plate starters, but both can be pitched at high krausen. To me it's a distinction without a difference.

But as noted above, when you ferment beer, you create an environment favorable to the beer. When you grow yeast, you create an environment favorable to the yeast.

Your baby fermenter will work too, you just more volume than a starter to create the same cell count.

 

[iandanielursino]

Your baby fermenter will work too, you just more volume than a starter to create the same cell count.

Which I think gets us back to the discussion of pitching yeast cakes and/or pitching skimmed krausen as in the days of old.

 

[CascadesBrewer]

Proponents of SNS say it's superior to stir plate starters, but both can be pitched at high krausen. To me it's a distinction without a difference.

I agree. For years I just did a starter the evening before brewing in a 1L flask with just the occasional shake. I moved to a process that more closely followed the SnS method (evening before, 1L starter in a 1 gallon jar, shaken before pitching yeast). I picked up a cheap stir plate a few years ago. If I make a similar starter, I am more likely just to use the stir plate, but I doubt there is much difference from stir plate vs SnS.

The stir plate really shines when I am trying to build up cell counts, say with a 2L or 3L starter. At about 24 hours, the starter turns milky due to all the yeast in suspension and I end up with a thick layer of yeast after cold crashing. Most yeast cell calculators allow you to specify if using a stir plate, and say that using a stir plate generates about 2x as much yeast. That seems to line up with what I see.

I mostly direct pitch dry yeast these days and skip making a starter.

 

[iandanielursino]

I'm super interested in doing lagers so I guess I might end up doing a stir plate if that gives you more cells.

I'm confused what 1L and 2L starters are, I've seen some people say its about the size of the container and others say it's about the amount of fluid.

Like I say, I'm thinking eventually of making like my own version of "fast pitch" by pressure canning wort, not sure if I should do concentrated wort or not and what size, basically I want a solution that will work for my 6.5 gallon lager batches for the most part.

 

[HighVoltageMan!]

I'm super interested in doing lagers so I guess I might end up doing a stir plate if that gives you more cells.

I'm confused what 1L and 2L starters are, I've seen some people say its about the size of the container and others say it's about the amount of fluid.

Like I say, I'm thinking eventually of making like my own version of "fast pitch" by pressure canning wort, not sure if I should do concentrated wort or not and what size, basically I want a solution that will work for my 6.5 gallon lager batches for the most part.

Generally speaking, it’s best to have @ double the size of container needed as the starter, 1 liter starter in a 2 liter flask. This is a common in labs as well as at home. It creates an ideal surface area for the exchange of gases. But it works to make a 2 liter starter in a 2 liter flask. The biggest problem with this is the krausen gets too high and pukes. I often make a 4 liter starter in a 4 liter flask (5 liter would be better). It’s not ideal, but it works pretty well. I use ferm-cap to keep puking down.

I also can wort. I make it double strength and 1.036. If I make wort starter specifically, I make it double strength and can it in pint and quart jars. When I make a starter with this wort I mix it in equal parts of bottled water. Bottle water from the store is sterile, so no boiling is required,

When I have extra wort from making a beer, it's usually a gravity of 1.050, so I dilute it with distilled water to 1.036 and can it in pint and quart jars. In that case you just add yeast and go. I try to use old grain or left over wort to make starter wort. It saves money, downside, it takes time.