Really low OG

[HeavilyMalted]

Hi, new to the forum, representing from London, UK. I completed my first ever home boil yesterday (done 100s of kits). It was a massive learning curve but I do have one question regarding a low OG I'd like an opinion on.

It was a part mash of 4 gallons topped up to 5 in the fermenter. I poured it into the fermenter from some height and tried to shake it up after it had cooled to limited succes. I let it cool to a little over 60 F (didn't realise how much time this really takes and wanted to pitch before bed!) in my sink full of cold water and about 15 hours ago took my OG reading and pitched the yeast. Unfortunately I didn't take a previous reading so have no clue what my efficiency is, but the mash does have a strong, dark colour! The OG reading was 1.028!!! I would be expecting at least 1.040 if not much higher. What is the most likely reason and what might be the effect to the beer. Fermentation has started but its quite slow too and i'm concerned i'm gonna end up with a very watery brew. I have a few ideas e.g. top up water has settled on top, temp was still too high or I bungled the sparge....but I'll leave it open to more experienced thoughts.

Many thanks

 

[BrewScout]

Probably didn't mix top off water too well and that threw your reading off. As for knowing your efficiency, chalk that one up a learning experience. Nothing you can do about it now. RDWHAHB

 

[HeavilyMalted]

Thanks, that's what I was hoping to hear, but it's nice to hear it from someone else. It's doing pretty well at the moment anyway so fingers crossed I just didn't take a representative reading. I'll have to judge the strength the old fashioned way, how many 'til I'm on the floor...

Cheers

 

[ajf]

I agree that inadequate mixing is probably the answer, but if you followed a recipe designed for US gallons, and made the brew using imperial gallons; then your OG will be about 20% lower than you want because the imperial gallon is about 20% bigger than the US gallon.

-a.