Low OG reading

I brewed a Bitter Brown Ale yesterday and my OG was 1.045 (after the yeast had been added; I forgot to take the sample beforehand). According to Beertools my OG ought to be about 1.067. I have no idea what went wrong, because I have done similar recipes many times. This was a 3-gallon batch with a boil volume of 1.5 gallons, which usually reduces to about 1.2 gallons.

I did have trouble maintaining the temperature during the mash. I wanted the temp to be about 150F, but my brewing thermometer kept jumping up to about 160-165. That didn't seem right to me, so I found a candy thermometer in my kitchen and placed it in the mash. To my surprise the thermometer read 145-150F. This confused, me, because I didn't know which thermometer to trust. So, I went with the candy thermometer, since it is meant for hot liquids. Therefore, I let the mash go an extra 15 minutes (original 30 minutes) to make up for the time it may have been sitting at 145F. I would say, on average, according to the candy thermometer, the mash temp was around 149F.

Given the struggles above, the only reason I can think of to explain the low OG reading is that I didn't get much from the specialty grains. But, even if set all my specialty grains to zero in Beertools I should get a gravity reading of about 1.058. Still, much higher than what I actually got.

I check the hydrometer and I didn't see any cracks or anything.

Anybody experience this or have any idea of what is going on?

Thanks

So this was a partial boil? If so then I'd be willing to bet you didn't mix the wort enough before taking your reading.

wyzazz said:

So this was a partial boil? If so then I'd be willing to bet you didn't mix the wort enough before taking your reading.

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Yeah, 1.5 gallon boil, which reduced to about 1-1.2 gallons. I then added the rest of the water right before the yeast.

You think I should take a gravity reading now? I am not sure if it worth messing with the beer now, because the yeast is pretty active already.

Can I calculate ABV after fermentation, before carbination? I don't know any other methods other than taking gravity readings.

Thanks

If you were using extract, and you used the amount you planned of both water and extract, your OG is almost without a doubt what the software said.

As it ferments, it will mix well. Your FG will be acurate.

Yeah I wouldn't worry about it. It is extremely difficult to miss your OG with extract if you use the right amount of ingredients, and end up with the right volume

So I should just assume my OG is what Beertools predicted and just take the FG in a couple weeks?

I know for a sure I added the right amounts of everything. I had temp issues, but nothing too crazy.

Thanks for the advice. That puts my mind at ease.

DanOmite said:

So I should just assume my OG is what Beertools predicted and just take the FG in a couple weeks?

I know for a sure I added the right amounts of everything. I had temp issues, but nothing too crazy.

Thanks for the advice. That puts my mind at ease.

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Correct, it'll be close enough that the ABV won't be very far off.

Bump

So, it has been 10 days since the brew and hit an FG of 1.0166 which is almost exactly what beer tools spit out for the predicted FG=1.016.

I am hoping that means everything went well and I didn't mess up too bad. I do think my final wort volume was a little low, since the boil did seem to get a little out of hand a few times and splash up some of the wort. Even so, I don't think I lost more than half a gallon due to evaportation and splashing.

Thanks guys

Sounds like it went well, congrats and enjoy.

Thank the Beer Gods for the search feature. I just took the OG of my second brew (and I never took the OG of the first one) and came out at 1.032 (expected OG was 1.044). It's an extract with specialty grains; I couldn't see how I could really miss the OG that much given that the majority of the grain bill was LME.