Does the 72 hour rule also apply to starters?

So I made a starter for the first time. Boiled a pint of water with 1/2 cup of DME, cooled and pitched my white labs vile I received by mail from Northern Brewer (+1 to them for great service).

48 hours later, my solution is cloudy, minor layer of yeast on bottom but I've noticed no major activity. Currently I see a few very fine streams of bubbles coming up which shows me there is SOME activity, but no Krausen or anything like that. I would like to brew tomorrow but if the starter isn't ready, I can wait.

Is it possible the yeast didn't make it through shipment? Should I build the yeast up again with another starter, or like all things homebrew, let time make it better?

Cheers and happy friday.

sounds to me like your starter is working and will probably be ready for you to brew tomorrow.

bubbles = good

Most starters are pretty much done by 48 hours. Most of the activity in a starter happens in the first 12-24 hours because of the lower gravity and lower volume of wort. Normally you do not get a dramatic krausen, just some floaties or a light yeast ring. The yeast are on the bottom because they are already done and have flocculated. The bubbles is the CO2 in the beer and some yeast cleaning up the fermentation by products.

Did you use a stir plate?

Yup... sounds like your fine. Bubbles of CO2 and cloudyness are the good (and sometimes the only) signs of a healthy yeast starter. I don't get a kraeson until my starter moves to quart or better. And some yeasts, like my WL830 (German Lager) don't do a kreason ever! The best indicator is using your hydrometer, but I found it ungaingly to use for starters, and I don't like the risk of infection. Try giving your start a good shake. If you get lots of foam, your in good shape. Shaking the starter drives off CO2 and aerates the yeasties, giving you billions ands billions of happy, healthy yeast cells. RDAHAHB.

If you didn't use a stir plate, you would have gotten more growth (compared to just leaving it sit) if you swirled it occasionally. That's what I usually do. When I do that, I can tell it's working because:

1. I get a pretty big layer of foam on the top of the beer.
2. The foil on the top of my jar makes sounds like it's releasing CO2 pressure from the jar.
3. I can smell the yeast in the gas that comes out of the jar.

In the future, you should make a bigger starter than a pint (especially if the pint is pre-boil volume). I don't recall where I read it, but the minimum size for a starter is 1 liter. You can see how big of a starter you need by using the pitching rate calculator on mrmalty.com.

I'm sure your starter will be fine your beer tomorrow though. Depending on the gravity of the beer, you might be pitching on the low side of the scale, but probably not low enough to cause a stuck fermentation or excessive esters.

Just gave the starter a healthy swirl and it foamed up like i just opened a shoke up coke bottle!
I figured a hydrometer reading would not be appropriate since i would need about half my starter just to fill up the hydrometer tube! Im brewing a higher gravity beer (around 1.070) so I am glad that this starter worked out.
I am going to be pitching it in about 15 hours. Should I stick it in the fridge to let the yeast settle, decant the liquid then just put the slurry in or is the whole kabootle fine? Its a christmas ale so i am not too worried about the taste being affected by the starter.
Like i said, this is the first time I have made a starter so I am a bit unfamiliar with the procedures. Thanks for all the input so far.

I don't think the fridge would be necessary. I've heard of people pitching their 1L starters without problems.

Since you are doing a pretty high gravity beer, I would recommend growing your starter. To do that, you would take what you currently have and pitch it into a 1.5L volume of boiled cooled wort. Here's a link to a pitching rate calculator on Wyeast's website (you can consider the amount of yeast in a vile to be equal to that in an Activator pack):
http://www.wyeastlab.com/hb_pitchrate.cfm

On their pitching rate page (http://www.wyeastlab.com/hb_pitchrates.cfm), they recommend using 12 million cells/mL for a 1.070 beer. With your current starter, you only have about 7.

Since this is your 1st starter, I understand if you don't feel comfortable doing this or have a jar large enough for a 1.5L starter. Chances are your beer will turn out fine, but you will be risking a stuck fermentation. Good luck and let us know how it turns out.

You don't need to decant even if you had a full liter. With a 1.070 beer you shouldn't notice the difference.

For a 1.070 beer you are definitely still on the low side for yeast count, especially if you didn't use a stir plate. As jescholler stated you will see a benefit from taking the starter you just made and stepping it up by adding it to more wort in a larger starter. If you can, even going to 1 liter would be a benefit. 1.5 liters even better. With 15ish hours or so till you pitch you will be pitching the starter near peak activity which is totally OK, and actually recommended by some authorities.

Remember, a starter is growing yeast, not fermenting wort.

There's very little "activity" to be seen in a starter...they can be done in a few hours or take a few days, but rarely have I ever even seen the evidence of a krauzen. All that matters is the band of yeast on the bottom, if yo see it THEN you had activity.