Back to Shopping at

Fermentation finished overnight?

Just brewed the all grain Imperial Mild Ale, using a starter and the Windsor dry yeast. The wort was working hard when I went to bed that night, and appears to have finished. The gravity is now 20 points less (from 1.040 - low, for some reason - to 1.020) than it was. I see no further fermentation activity. Could it really have finished overnight? It was over 85 degrees in the house overnight; could that have done the yeast in? Any ideas? Thanks!

What is the recipe? 1.040 is a strange OG for an Imperial beer.

85* would not do in the yeast. It would allow them to party hard and finish overnight though.

Have you checked your hydrometer for accuracy?

With ambient temps in the 80s (thus pushing beer temp maybe up to 90F from heat of fermentation) and with a low OG, yes, the yeast could have finished overnight.

Couple of pointers: don’t make starters with dry yeast, just sprinkle on top of the wort, especially with such a low OG (one packet is good up to about five gallons @ 1.060); and, chill your wort into the low 60s before pitching and keep the beer temp in the mid-60s for at least the first couple of days (do a search for “swamp cooler” on this forum for a cheap and easy method).

Thanks, Shadetree and Nighthawk. I don’t know why the OG was so low - though I measured it before I put in the pound of corn sugar at the end of the boil, so it may have started a little higher. I think I need to learn more about sparge amounts, since the NB all grain recipes say nothing about it, and I’m usually at least a little below the predicted OG. I follow the recommended sparge amounts iBrewmaster tells me, though.

I’m surprised Shadetree says not to do a starter with dry yeast. I thought a starter was always a good idea. Always learning!

Thanks again,


Dry yeast have more than enough yeast in the pack to ferment a 5 gallon beer the an OG in the 1.070’s. Some people says the a starter will deplete the reserves the yeast have. Making a stater counter productive.

The kit says an OG of 1.062. You either didn’t have enough grain, poor crush, or ended with more than 5 gallons.

If 1.040 was before the sugar, 1lb of sugar will add ~1.009 to 5 gallons. You are still ~10 points off.

Thks, Nughthawk. I don’t know why my OG was so low. I used the Northern Brewer all grain kit, crushed it myself as I always have, and ended up with less than five gallons. Low efficiency is all I can think of, unless NB made a boo boo in the grain bill. I sparged following the amounts listed by iBrewmaster, so it’s a mystery. I’m often about 5 points low in my OG, but never this low. I just racked to the secondary, and it tastes good, even though it won’t be true to style.

Aha! My hydrometer does read low - though only by the .05 I’m usually off! Time for a new one, or maybe a refractometer.

You can try gently tapping the hydrometer to get the paper to move.

Back to Shopping at