Starter Question

Hey guys,

I made my first starter yesterday and I'm looking for some guidance/reassurance. I made a gallon starter because my smack pack was a couple months old, and I used a pound of weisen DME, so it's pretty high gravity, come to find out. I pitched the swollen pack of Ringwood Ale yeast (so I know it's viable), but it's been about 20 hours and I seen no appreciable activity. I don't have a stirplate, so I'm using the intermittent shaking method on Mr. Malty. I was hoping to have activity at this point, so I could chill for a few hours prepitch, and decant some of the extra volume.

What are your thoughts? Should I try to adjust my brewday volumes to account for the extra starter? Is my yeast even viable if I haven't seen any activity in close to 24 hours? I haven't used Ringwood before, so is it possible it's just a little slow out of the gate, and will be fine in the long run? I have a S-05 cake I can pitch on. If I did that, and let the starter continue, would I be able to decant, refrigerate, and use the starter for my next brew?

Just looking for some feedback, as it's my first starter, and I'm not too sure what I should be seeing right now.

Thanks.

That OG is going to be a little high, people apply the 10:1 ratio by weight to this is easily done in with the metric system eg 1 liter with 100gram of DME. The target OG is 1.040, although it sounds like a lot of DME your starter was not far off this 10:1 ratio, with a US gallon being 3.8L and you used 16 oz = 480 gram you were a little heavy but not too much. The reason for keep the gravity light is, heavy gravity puts strain on the yeast cell walls their by taxing their health. Now if you are not using a stir plate using a high OG is really going to decrease health as the yeast will run out of O2 and so they will be fermenting anaerobically and this taxes their health. Where lower OG will mean the O2 to sugar ratio is closer so you will get less cell growth but better cell health.

In your case if you want to increase the cell health you can step the starter, when the starter has finished, just put in the fridge for about 24-48hrs the yeast will form a cake on the bottom of the vessel and then you can decant off the spent starter wort and add some more cooled (boiled wort) on top of the cake and then start again using the yeast in the cake to kick off your starter.

This is called stepping up your yeast, although normally you would increase the size from 1 gallon to 2 gallon (it is another long story why) but in this case you are OK to just step into the same size. If you do this you have just learnt and important skill stepping yeast starters, next time you can do a 1L starter and then fridge, decant, add 4L of wort to your cake and you will have tons of yeast to pitch. This takes a little longer but makes better yeast. You don't want to pitch your yeast into too larger starter as then it takes the yeast longer to get a foot hold in their new home and any errant bacteria might take over your starter as they multiply 6 times faster than yeast.

This is a simplified explanation of some of the concepts on the complex subject of yeast cell growth, just remember starters are to do three things in order of priority:

1) Verify viability of yeast, in summer sometimes you dead yeast or the yeast might be old
2) Improve yeast health, weak sugar solutions are easier on yeast
3) Increase cell count.

Clem

So I shook the crap out of the starter, in an attempt to oxygenate it better. I have a yeast cake that I will be bottling off of today. Would I be better of pitching onto part of that cake, rather than pitching the starter as it sits?

Shaking is a great way to oxygenate your wort however the yeast will consume that quite quickly as air and shaking will only lead to 10ppm O2 in solution no matter how hard you shake it. To increase O2 and hence cell health and growth rates you need to shake it again and again to keep the oxygen levels up or make a stir plate.

Pitching onto a whole cake is the definition of over pitching, some people argue that this does not effect the brew however pro brewers don't do this and the science says that the ester profile of the beer is effected and ales are all about yeast esters. So if you have a cake just take sanitized a mason jar or other that is available and use only part of the cake. The is various different tools for estimating yeast count in a cake, based on guesses like trub content etc. The deciding thing on whether to use a yeast cake is what was the previous beer you brewed. If it was a low OG beer and did not have a lot of hops then yeah go for it! If it as a DIPA then heck no that yeast is trashed and the trub will have a lot of hops in it so you will have half dead yeast mixed in with lots of used hop matter. Anyway your yeast in the starter is fine, You have check off two out of three of the requirements of yeast starters; you increased count and confirmed viability. The point about yeast health was an ideal situation calls for wort around 1040, they won't fail you just because yours was 1050 they are still healthier than when you starter. I just wanted to point out an ideal yeast starter to educate. I say use the starter yeast.

Clem

Well, I pitched on the cake. It was s-05 from a 5 gallon batch of IPA. The beer I put on top of the cake was 7 gallons of a higher-OG american brown, that I wouldn't mind being a little hoppier. It's perhaps a slight overpitch, but probably not by much. Fermentation started in about 4 hours, which probably wasn't an ideal lag time, but throwing the starter in during active fermentation might have had fairly similar results.

I decided to let the starter do its thing and then use it far a later batch. It is finishing now, so I'll cold crash it, decant, and pour into a sanitized mason jar for my next batch.