First-Ever Homebrew Help?

How much yeast of what type did you add? How old was it?

All that said, a 12-24 hour lag to begin fermentation is desirable, as during the replication phase a lot of the flavour compounds in a beer are produced. When I see people bragging about how they saw active fermentation in 2 hours I chuckle to myself as that short a lag is indicative of over pitching, which can be detrimental to a beer's final state.

 

Chances are there is no problem. The only thing I would do at this point is make sure the wort temperature is somewhere in the recommended range. I don't know what yeast strain you're using, but for a hefe we're probably talking somewhere around 62F-68F.

 

Time to repitch.

Lags up to 72 hours are fine and sometimes a result of the strain. After that It's a sign of weak yeast.

 

If I was getting lagtimes of up to 72 hours with any strain, I'd consider it a problem, and be looking for solutions.

 

His lag is at 18 hours now.

That's a dry yeast so freshness is much less of a concern. That said, was the pack sealed that you were using? Do you still have the rest of the pack? Did you rehydrate your yeast or just dump it in?

If it was unsealed it may not have been in its best state.
Dumping it in kills ~50% of the cells, but many people get good beer doing that still, it just affects their pitching rate.
If you have the rest of the pack that's great because you can do two things:
1 - Proof the yeast to see if it actually is viable
2 - Repitch more yeast if you hit about 36-48 hours without activity.

 

http://www.howtobrew.com/section1/chapter6-5.html is a good overview of the correct process.

 

Why not the whole packet of yeast? Sounds underpitched to me, but I don't use dry yeast, so..

Regardless, just let it sit for another day and see what happens. The yeast could be working, you just don't see it yet. After 48 hours, if I haven't seen anything I'll start to go through the process, chances are it's fine if you used enough yeast.

 

A 2 gallon batch... MrMalty suggest 0.4 11.5 gram packs for 2 gallons of 1.048 (guessing at OG, but it is a Hef)

 

See, I skipped that part.. Small batch.

With that said. Wait it out, OP. It'll get there, and be done quickly.

 

Personally I don't disagree, but as a rule I don't sweat inside 72 based on what I've seen with some strains and tasted in fellow brewer's beers

 

With pure brett I've seen lags up to a week

 

For a 2G batch size...1/2 pack dry yeast is enough for a most worts.
Pitching two level teaspoons is an easy and convenient way to measure the right amount.

 

I'm assuming you got some really good fermentation going on that by now - possibly even slowing down a bit. How does it feel?

 

No matter what happenedto your first berow, its begging of something amazing

 

Some nice picture from"Beer Here: Brewing New York's History"