If the weather is warm and with some strains of yeast (usually dry yeasts) it is not uncommon for beers to ferment very quickly. Take a hydrometer reading and record the value (don’t forget to apply any temperature correction). Wait three days and take another. Compare the two readings. If they are the same (and in the proper range), your beer is done fermenting. You could bottle the beer now (we know you’re anxious!) but we advise you to wait a full two weeks to allow the beer to settle and clear. If your hydrometer reading is still high, then your fermentation may be stuck. Some dry yeasts (not the ones we sell, however) are known to do this, but the most common cause is insufficient aeration of the wort when you pitched the yeast. It can also be caused by a highly flocculent yeast strain that dropped to the bottom before it was done. In either case, you can usually get your beer going again by “rousing” the yeast. Do this by stirring up the yeast sediment with your sterilized brewing spoon.