Very low SG reading

[vitrael]

Noobie question time!

I made a ESG recipe out of Papazian's book today with an estimated starting gravity of 1.050-1.060. 5lbs DME, 1lb corn sugar, 1 cup brown sugar, 1 cup molasses all contributing to gravity. I had a partial boil of a paltry 2G which, by the time the 60M boil was up, looked like motor oil.

After it was racked to the fermenter I topped it off to the 5G mark and agitated it. My agitation method was setting the carboy on its side and rolling it around.

I took a gravity sample and pitched the yeast. To my total chagrin the gravity reading was 1.025. I had a spare hydrometer, so I took a reading with that one too, also 1.025. Then I calibrated them both in water at 1.000.

THE CASE OF THE MISSING MALTOSE!

I know there's a slight adjustment because the wort was somewhat warmer than the hydrometer's calibration at 60F, but nothing like that disparity. I attribute this to the top-off water not being adequately mixed with the concentrated wort. To my eye it looked pretty well mixed, but then again, it was jet black all the way through.

So, do you think my mixing hypothesis is correct, and if so, what's a better way to agitate a 60lb filled carboy than rolling it around? New top-off method? (full boils are not an option)

 

[Kaz]

I would think your mixing method is sound. And even with only the 5lb of DME your O.G. should be about 1.045. Are you sure you read the hydrometer properly.

 

[dcp27]

It just wasn't mixed well enough, its very difficult to mix wort and water well enough to get an accurate reading. your OG should be about 1.056 is you're at 5gallons. in the future I would suggest taking your reading before topping off and then adjusting for the final volume:
batch OG = post-boil OG * post-boil volume / batch volume

 

[theredben]

As long as you weighed the items properly you will have the right gravity. By the time the yeast get to work it should be thoroughly dispersed.

Partial boiling a 1.060 beer in 2G! I am guessing it burnt a bit on the bottom! You could always boil the sugar additions beforehand and then boil the DME.

 

[Gated312]

I often think I mix it well enough, but don't either. For extract, far as I know, not a big deal because it ends up circulating or whatever and mixes completely anyways. But as for mixing methodology, just pour it between two pails (if you have them). Seems to aerate/mix it pretty good.

 

[vitrael]

I'm sure I'm reading the hydrometer properly, as I read 1.000 in water and 1.025 on both hydrometers when they float in the test flask.

dcp27, I didn't realize there was such a simple conversion Thanks for the tip! Next time!

theredben, surprisingly no! I burnt a bit on the bottom of my first extract batch in 3G, a 1.050 beer. This time I had a diligent stirring partner while adding the sugars and extract and the pot was ***** and span after removing trub and giving it a rinse today.

 

[smizak]

This is one of the most common posts for beginner brewers. It was my first post here as well.

You didn't mix it enough. I did the same thing. When my beer was finished, after three of them, it was obvious that it wasn't the 3% ABV beer I feared it would be.