How much dry yeast to pitch for 1g batch?

I've been doing a lot of 1 gallon batches lately and have been getting great results with the dry yeast I've been using. I've been pitching 1/2 a packet of it for every batch and the fermentation has been very vigorous. Last batch I pitched 1/3 of a pack and it worked just as well.

Today, I pitched 1 1/2 teaspoons into a 1gallon batch in an attempt to try to standardize my pitch rate a little more. Now I'm starting to second guess myself and thinking I should go back and add more.

Is there is a recommended amount of dry yeast in teaspoons to pitch for a 1 gallon batch of beer?

You should really use a pitch calculator and a scale, there are some super cheap scales out there to help you. Also, it is going to depend on your OG how much you should actually pitch.

That being said, most 1 gallon brews tend to need 3-5 grams depending on the size of the beer. So 1/3 to half is acceptable but not the best for getting a correct fermentation going

http://www.mrmalty.com/calc/calc.html

Put in you expected O.G., the volume (1 gal) and select the "Dry Yeast" tab.

Ah thanks guys, much obliged

So I woke up to a surprise this morning- the pressure from the yeasts fermentation had blown my rubber stopper & blow-off tube off the fermenter. While I was re-sanitizing everything and cleaning off all the yeast residue that had climbed down the outside of the fermenter, my only thought was "Well... pretty sure I pitched enough then, I guess that answers that." But its nice to have a more accurate answer from you guys, just the same- I'll be using Mr. Malty from now on!

After having my stopper and blow off tube blown out 2 times on my 1 gallon batches, I started duct taping down the stopper.

Oh no! Haha I guess its bound to happen sometimes. How'd the beer turn out?

Duct tape was my first thought too, sadly I had none on hand. I ended up just rigging a rubber band around the rubber stopper and the handle of the jug with a pen through it, like a sling shot... a practice which I will be adopting for every 1 gallon brew from now on

Both turned out fine. So much stuff was coming out that nothing could get in to cause an infection.

That makes sense, glad to hear it