Double Stout SG and FG - Stupid Question?

[walzo]

So I read of a recipe somewhere years ago that suggested adding 1 tin of coopers stout and 1 tin of coopers dark ale.

I did just that.

I added 1kg of Coopers BE2.

While finishing up, just before adding the yeast, I couldn't remember what the suggestion was for yeast, add both from each tin or just the one. I figured it was just homebrew, what could go wrong, just add both. I did just that.

Registered an initial SG of 1120. I originally questioned this figured but I did another batch, much more simple, coopers european style, came out with accurate figures, or as expected anyway. I bought a new test tube to float the hydrometer in because I don't trust those dodgy ones that come with the cheap hydrometers. So I'm inclined to believe the figure. Pretty sure I tested it three times to confirm.

So, within about 20 minutes of closing the lid it was bubbling, then an hour or so later it was frothing out through the airlock. Sort of expected that part.

Today, 7 days later I tested the FG. 1028. Giving it a rough alcoholic percentage of 12-13%.

Obviously the math is pretty simple, ((OG-FG) % 7.46) + 0.5 so the stupid question is...Is this possible.

I would expect adding the two tins and a 1kg of fermentables that it COULD be, but figured I'd ask the wise bunch here.

Cheers.

 

[btrots87]

Even with those ingredients that OG seems very high assuming you did something close to a 20L batch. Are you sure that everything was mixed well before you took your reading? If it's not mixed well the higher density liquid will fall to the bottom so when you take some from the tap to do a gravity reading it looks higher than it really is.

 

[walzo]

That could explain it. But I'm pretty certain I was stirring it while I was filling with cold water so it should have been well mixed. But who knows, I thought it was strangely high was well.

I can't guarantee it was more than a 20l batch though. These are secondhand fermenters that I got for free (I started on a very tight budget) , they're only small, under 23L full, easily, and the last few batches I've done have struggled to fill a Korny so it may be been closer to 18-19L.

I guess the proof will be in the pudding.

 

[Mattrox]

Ian's Spreadsheet says 1.078 for 18L or 1.074 for 19L if you get a FG of 1.025 you will have 7.1 to 7.4%.

The OG from the spreadsheet is pretty spot on and more reliable than the hydrometer for OG due to syrup not always mixing.

 

[yum beer]

By my calc you would need to be around 14-14.5 litres to get that high an SG.

 

[walzo]

It should be at least 18L, at least.

I don't mind 7%, but 12% is a bit over the top.

Thanks for the replies, must have just needed more of a mix first.

 

[danestead]

What temperature was the wort at when you pitched the yeast and did you aerate it at all? It just seems a bit odd that it would be foaming out the top in an hour. You mention you started on a tight budget so I assume you are fermenting at ambient temperaturw in your laundry or something like that rather than in a fermenting fridge or similar. If you are fermenting warm (hotter than about 20 degrees) may I suggest you look into ways of cooling your wort down to about the 18 degree range (when you are using an ale yeast which is what most kit yeasts generally are). If you search AHB or google there will be plenty of info. on ways of keeping your fermenter cooler. Your beer will taste far nicer if you use a temperature cooler than what summer in australia gives us! If you didnt pitch the yeast into warm wort Im stumped as to why your ferment started so quick because it does sound odd.