BeerBorg

I made a 5 gallon coopers batch a few weeks ago

1 can of coppers Canadian blonde
2 pounds of muntons light dme

My og was 1.032 and my fg was 1.008. By my math that works out to 3.15% abv

Shouldn't the coopers alone come out to that? Shouldn't the added dme make it higher in abv?

On qBrew, for 5 gallons, I work out an OG of 1.043 for 4.2% ABV. Definitely undershot the OG by a lot. With your measured OG, your FG is spot on. Searching for a picture of the can, it says the net weight is 3.75 lbs, but Cooper's page lists that it's 3.3 lbs of extract in the can. I think that the low OG was due to not using all of the extract in the can (left some syrup in it). Another reason might be that you diluted the wort beyond 5 gallons, probably closer to 6 gallons.

When my gravities are off, it's usually water volume.

Gotta stop pouring in those Imperial Gallons Paul! LOL!

Each one of those is 1.2 U.S. gallons ehh?

BigPapaG wrote:Gotta stop pouring in those Imperial Gallons Paul! LOL!

Each one of those is 1.2 U.S. gallons ehh?

LOL Well I was gonna type in 23 litres, but I know this isn't a predominantly Canadian site.

There's two possibilities here I guess....

Too much water? Maybe, but I think I only used a total of 22.5 litres including the boil.

The other thing that I haven't mentioned because it didn't occur to me until now is..... my boil over. When I added the DME to the boiling water it made a really big mess of our brand new stove (SWMBO was NOT impressed). I didn't think I had lost that much, but would any loss affect the final product?

22.5 L is 5.94 gallons, so that's most likely what did it.

Also, with DME be very watchful of the hot break. Keep a spray bottle with water in it handy to tame it, or pull it away from the heat, then put it back when it dies down and lower the heat. The boil over certainly made you lose some wort so less wort volume means you have to add more water which dilutes it and brings your gravity down.

For future reference, 5 gallons is just a hair shy of 19 liters.

This may seem really stupid but have you checked the accuracy of your hydrometer? I had a hydrometer that the paper scale had become loose in and slid so it wasn't giving proper reading. I figure it out when I put it in regular tap water and it was reading 1.010 instead of 1.000. I believe that it had been jostled between the OG and FG and threw my ABV way off from what I was expecting. I was able to get it back into place by gently tapping it on the counter to get the paper insert back into place. That hydro is my back up now since I bought a new one and I now check the accuracy with tap water before I take any reading.