Is this even possible?!

[lwcm]

I brewed up the Northern Brewer PM-Oatmeal Stout (first time with PM and I likes it!) on Monday and was more than a little surprised at my OG. The recipe sheet predicts a OG of 1.049 but when I finished and took my reading it was 1.065 at about 80F. I mashed in a 2 gallon cooler with 5 quarts of strike water and was able to hold the mash to 151-150 over the hour mash time. Sparged with 5 quarts of 170 water just like the sheet told me too. I am at a loss to explain where all these gravity points came from.

I thought it must be my hydrometer but I calibrated it using two different thermometers and it is spot on. I know that it will be beer and I should RDWHAHB (and I did while listening to the airlock chug away happily) but I'm very puzzled. I've overshot the OG for every single NB brew I've done since I started keeping records (all extract: Nut Brown (pre MO), Cream Ale, Dawson's Multi Grain Red, and Nut Brown (with MO)).

Only thing I can think of is that I am not adding enough dilluting water but it's right around 5 gallons in the carboy, give or take a smidgen. So I'm not sure.

What says the hive mind?

 

[JLem]

A couple of things come to mind:

1) the markings on your carboy/bucket may be inaccurate - these marks are not intended to give you any sort of precision.

2) you are not taking a sample from a thoroughly mixed wort. Since you are topping off with fresh water, which is MUCH less dense than the concentrated, sugary wort, it is very difficult to fully mix the two together (no matter how much you think you stirred, shook, rocked, etc. Normally this results in a lower than expected OG since the fresher water sits on top, but depending on how much you stirred and how you took your sample it is entirely possible to sample from a more concentrated "pocket".

Btw, what was your recipe? What type and how much grain did you mash and how much extract did you use?

 

[Pickettj]

I'm a little disappointed that this thread is so short. I had a similar issue with a bock. I brewed and missed my gravity but nailed FG. The calc ABV went from an expected 6.5% to a staggering 8% or so. I don't know if I missed a calculation or if not adding enough top off water will result in a stronger beer. Does "under diluting" a Partial Boil cause any real issues? I tried the bock and it tastes pretty damned good (aged 4 months). It's dry as hell, but good. I am coming around and asking about this because I'm considering replicating my mistake on purpose this time. I would be making a 4
Gallon batch with a 5 gallon recipe. Any thoughts on this idea? (I think it relates enough that I'm adding to the OP question but if you don't think so, I'll gladly start a new thread).

 

[JLem]

I'm a little disappointed that this thread is so short. I had a similar issue with a bock. I brewed and missed my gravity but nailed FG. The calc ABV went from an expected 6.5% to a staggering 8% or so. I don't know if I missed a calculation or if not adding enough top off water will result in a stronger beer. Does "under diluting" a Partial Boil cause any real issues? I tried the bock and it tastes pretty damned good (aged 4 months). It's dry as hell, but good. I am coming around and asking about this because I'm considering replicating my mistake on purpose this time. I would be making a 4
Gallon batch with a 5 gallon recipe. Any thoughts on this idea? (I think it relates enough that I'm adding to the OP question but if you don't think so, I'll gladly start a new thread).

What was your recipe? All-grain or extract? How big a batch size?

 

[Pickettj]

What was your recipe? All-grain or extract? How big a batch size?

The recipe was a bock. It was an extract recipe with specialty grains and intended final volume was 5 gallons. I ended up with 4.

 

[duboman]

Bottom line, regardless of extract or partial mash and you add top off water there is always the possibility that you do not get a good mix between the wort and the top off water causing an incorrect reading.

BTW, for a partial mash you should really be doing a full boil. Also, you cannot calibrate a hydrometer using a thermometer, you calibrate it in distilled water and it should read 1.000 at 68F (Or whatever temperature is listed on the hydrometer paper as its calibration point) A thermometer is used to simply adjust the reading due to a temperature other than the calibration temp (Keep in mind, anything adjusted over 100F is kind of worthless)

Also, be aware that the paper inside the hydrometer can come loose and move throwing everything off so it is a good idea to calibrate it periodically to be sure its accurate.

 

[KurtB]

The recipe was a bock. It was an extract recipe with specialty grains and intended final volume was 5 gallons. I ended up with 4.

Being that it was an extract recipe without anything being mashed, unless the volume of water is different than what was used for the recipe calculation, it is very difficult to miss your original gravity.

In your case, your original gravity would have been higher than what the recipe initially stated due to the lower volume of water that you added. The added water dilutes the "sugar water" (wort) and it is the amount of diluted sugar which determines your original gravity.

When I first started out and made a lot of extract batches, it seemed like if I didn't dilute enough to hit my original gravity, the final gravity also ended up higher as well, but your results may vary.

That said, in your case I expect your original gravity really wasn't that much higher than what it should have been and your water and wort just were not mixed up enough before you took your original gravity reading. I am also assuming that you fermented a little under 5 gallons of wort, lost some beer to the trub in the fermenter, and really had a bit more than 4 gallons put into bottles (which I know are three big assumptions on my part).

 

[Yooper]

Being that it was an extract recipe without anything being mashed, unless the volume of water is different than what was used for the recipe calculation, it is very difficult to miss your original gravity.

In your case, your original gravity would have been higher than what the recipe initially stated due to the lower volume of water that you added. The added water dilutes the sugars in the extract and it is the amount of diluted sugar which determines your original gravity.

I agree. By making a 4 gallon batch out of a 5 gallon batch's ingredients, you've reduced the water 20%. That would increase the OG. The beer will be higher alcohol, "thicker" and maltier than the recipe planned for. It will change the balance of the beer.

 

[JLem]

For example...if you made a recipe that would have given you 5 gallons of 1.065 wort, only topping up to 4 gallons would result in an OG of approx. 1.081. Assuming a complete fermentation, those extra gravity points will result in a higher ABV.

 

[Pickettj]

For example...if you made a recipe that would have given you 5 gallons of 1.065 wort, only topping up to 4 gallons would result in an OG of approx. 1.081. Assuming a complete fermentation, those extra gravity points will result in a higher ABV.

That's what I thought. What happened is I put my brew in a carboy that I thought was 6.5 gallons. When I racked out into a bucket I had about 3.75-4 gallons (estimating because its based on a shadow through the bucket on the markings on the side). Through a little common sense I discovered it was a 5 gallon carboy. The end result was much dryer than expected. My gravity was way off to start but finished near normal so I wasn't sure if I had a bad reading or if it would really be that drastic if a change. I'll chalk that one up to beginners error, but it turned out delicious so I suppose it was a happy accident...