Surprised inefficiency

This weekend I made a batch using my all grain setup. About a month ago i used it for the first time and got 75% eff with a hefeweizen. This time, i used a normall all barley ale (Manny's Pale clone) and i hit 1.030 for preboil, then 1.026 after boil and AFTER adding extract.

so 75% would be 1.056 OG.

How the heck did I not only miss it by a long shot using my same mash tun, but the wort diluted during the boil. This does not make sense to me.

Do hydrometer readings need to be at room temperature or can you measure if the wort is hot? It's just a density reading so it shouldn't matter.


any ideas?

i did this in BeerSmith. is this right?

It kind of looks like you just answered your own question. If you look at the beersmith tab you will see a calibration temperature. You put in the temp that you measure at and it will adjust the reading accordingly.

oh well that was a guess to use that tool. I swear i took gravity readings at hot temps before.

Don't ask me, I am pondering much the same issue. I mashed 10 lbs 2 row american light at 154F, batch sparge at 170 (close to 180 when added to MLT) . Pre-boil volume 7 gal. pre boil SG 1.030. I added 2 lbs brown sugar at 30 min and 2 lbs honey (not honey malt) at 15 min. Ended up with OG of 1.070 at 75 F actual temp and 5.5 gal into fermenter. I also added 13 large sliced jalapeno peppers (hop bag) for 20 min. This is a pepper beer I havemade often but usually with extract. Can the peppers change the gravity?
I looked at Brewers Friend and it showed high numbers for efficiency, waay high, like 113%. I suspect both of us are looking at something wrong, maybe in the way we take gravity readings? I had the same problems last time but the beer came out really good but high ALC. Hope someone else will chime in and offer better advice.

While calibrating to temps can work my experience is that generally any reading taken over 100F is suspect.

The best thing to do is make sure your sample is as close to 60 as possible and obviously make sure you hydrometer is properly calibrated.

Hard to get a preboil sample down to 60 b/c my mash comes out still at 155. Instead of chilling and waiting for results, i just move on to the next step.
as for post boil, if i chill it down to 68 for fermenting then find out it's low, i have to heat it up again

Wow...I'm dumb. I am still new to all-grain an didn't know that temp effects the gravity at the moment of measurement. Thanks all. That probably explains some bad efficiency that I get.

A refractometer is the best investment you can make in brewing. You only need a few drops to get a reading and it cools quickly. There is no waste and the readings are quick and easy.

I usually take a sample from my pot and put it in the freezer to let it cool down. It takes about 5 to 8 minutes. Then I take the sample as close to 60*. Not sure if this is the correct way or the way others do it, but it has worked great for me.

forstmeister said:

A refractometer is the best investment you can make in brewing. You only need a few drops to get a reading and it cools quickly. There is no waste and the readings are quick and easy.

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i don't waste with samples. i put it right back in the boil. as for post boil, i either taste it or my vial/hydrometer is sanitizes so it goes right back in. refractometers read gravity or do you need to convert their brix?

mendozer said:

i don't waste with samples. i put it right back in the boil. as for post boil, i either taste it or my vial/hydrometer is sanitizes so it goes right back in. refractometers read gravity or do you need to convert their brix?

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You know, I just gave somebody advice about not putting their sample back into the ferementer because that seems to be the norm. But like you mentioned, if everything is sanitized - Why not?

Good post mendozer!

mendozer said:

Hard to get a preboil sample down to 60 b/c my mash comes out still at 155.

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I grab a sample from boil kettle after sparging is finished; drop it in freezer and then fire the kettle. It is about 80* before the wort is up to a boil so I can adjust bittering hops up/down if needed.
I adjust the hydrometer reading based on the actual temp. Most are calibrated at 60*

mendozer said:

i don't waste with samples. i put it right back in the boil. as for post boil, i either taste it or my vial/hydrometer is sanitizes so it goes right back in. refractometers read gravity or do you need to convert their brix?

Click to expand...

Refractometer is not accurate for post fermentation, so my fg samples are done with a hydrometer. The refractometer is awesome for brew day.

ill keep that in mind. well, at least my beer will turn out great instead of being weak