First Starter

[TurboBrew]

Showing off my new toy and I got a couple of question:

I don't have a stirplate yet so should I be giving it a good shake every now and then? I shook it up pretty good after the boil

Should I be worried about over pitching on brew day? I only used 1/2 cup of DME in 1200mL so I wouldn't think so, but I figured I'd ask.

 

[Pelikan]

Don't worry about the stir-plate. In my opinion, I feel it's an unnecessary implement. Cool thing to have, but unnecessary. I agitated maybe five times the first 18 hours. Once I saw visible activity (effervescence) I stopped and just let the yeast agitate itself.

To my knowledge, the amount of DME you use doesn't have much to do with overpitching, but might have an impact on the integrity of the yeast that you first pitch into the starter. From what I've read, starters over 1.040 SG are hazardous to yeast health that early on.

That said, I went with 4 ounces (by weight) of DME per 1 liter of solution, and my yeasties have been chugging away for nearly 24 hours at this point. I also added 1/4 teaspoon of Wyeast nutrient to get them rolling as well. I'm not much for SG readings, so I'm fairly sure that ratio (which I found on some website or other) has to be inline, and the Whitbreads have been going steady.

You'd pretty much have to pitch a pint of pure slurry (ie: yeast cake or slime) to even begin worrying about over-pitching. I was worrying about over-pitching when I inoculated my starter with a tablespoon of slurry, then realized there was most likely far less yeast in that tablespoon than the average smack-pack...gravy, in other words.

Your culture is looking good. Got that little bit of head forming that indicates to me everything is healthy and rolling. The color looks right. I think you're golden.

 

[TurboBrew]

Sweetness. You said something about the yeast agitating themselves. Once fermentation begins, will the yeast oxygenate the wort themselves?

 

[flyangler18]

A stir-plate is a valuable piece of equipment to have if you are propagating yeast from, say, a bottle culture- where the number of viable cells is VERY VERY small and probably stressed. In this situation, you want the yeast to be growing and reproducing, not consuming maltose immediately. Any oxygen-rich environment puts the yeast in a reproductive phase and they will continue to do so until they reach saturation or when oxygen is absent. At that point, they will switch metabolic pathways and start metabolizing the maltose, excreting co2 and ethanol.

In the absence of a stirplate, swirling the starter often will keep the wort oxygenated and promote growth over maltose consumption. You may want to research a bit about adding olive oil (a teeny tiny drop) to the wort. This adds the sterols that yeast need for reproduction.

 

[Pelikan]

In other words, unless you're doing some serious yeast reclamation experiments, swirling the starter a few times before you see visible activity is fine. To the best of my knowledge, once visible activity is seen, the yeast is well on the way to displacing the O2 with CO2 -- so stirring is almost a moot point by then.

When the yeast enter into serious activity (the kind that produces the head you're seeing, and the bubbles in the wort & airlock), they're agitating the solution enough for their own purposes. I pretty much leave them alone at that point. One doesn't agitate a primary once fermentation has started, for example.

 

[scinerd3000]

. You may want to research a bit about adding olive oil (a teeny tiny drop) to the wort. This adds the sterols that yeast need for reproduction.

im just wondering where you had heard htis or if you have a reference. Just seems somewhat odd although i dont nessesarily doubt it works. Have you noticed any better results with it?

 

[flyangler18]

im just wondering where you had heard htis or if you have a reference. Just seems somewhat odd although i dont nessesarily doubt it works. Have you noticed any better results with it?

http://www.brewcrazy.com/hull-olive-oil-thesis.pdf

 

[scinerd3000]

http://www.brewcrazy.com/hull-olive-oil-thesis.pdf

thankyou. Its interesting but the only real benifit i see if the oxidation factor. Theres slightly lower saturations of DMS and other substances produced by the beer- some of which i would want. The additionals also caused more time to be speant on fermentation before it had attenuated all the way. In all but one of the experiemnt the attenuation and final gravity was better with the control group.....i think they have a ways to go but very cool article!

 

[flyangler18]

True, it does seem that there are some tradeoffs, but I limit this addition to my starters. I've not yet experimented with anything larger than 1L starter volume, but there's some anecdotal evidence here on HBT from people who have experienced very vigorous fermentation with appropriate ester formation during the growth phase.

 

[TurboBrew]

Lots of good info, interesting article. Should I be making a larger starter than I am currently? Should I be worried about using Extra light DME starter in a wheat beer?