problem with my OG

[Chefjp]

hello, I just made a batch and Im still having a lot of problems with my OG
I did an IPA here is the recipe

5 gallons
11.14 lbs pale malt
1 lb caramel 20
8 oz caramel 60

according to beersmith, this gives me an OG of 1.065 with 70% efficency

my preboil numbers where correct: 6.79 gallons of wort collected afetr sparging with a preboil gravity of 1.055, both right on the money.

I boiled for 90 mins. and cooled it i ended up having to had almost 1 gallon of water to achieve the 5 gallon volume, but my final OG droped to 1.042.

what I´m I doing wrong?

 

[gr8shandini]

Give it a good stir and try again. If you had nearly 7 gals of 1.055 wort, there's no possible way you can end up with 5 gals of 1.042. I think you just didn't get it mixed well and got some of the more diluted wort in your sample. Of course, that depends on your pre-boil reading being correct. Did you use a refractometer or hydrometer? Was it calibrated? If it was a hydrometer, did you make sure to cool the sample below 80F and apply a correction?

Also, I'd take it easy on the propane, there. You should have a healthy boil going, but you don't need to crank it up to 11. I lose about 1 gal / hour in my 5 gallon setup.

 

[a6ladd]

Why did you go for 90 minutes? Did you also account for evaporation for the additional half hour? If you compensated for that you wouldn't have to add so much top off water and your gravity would be a little higher. I don't have beersmith in front of my but 1.055 seems a bit on the low end for 11lbs of pale malt, but I could be wrong.

 

[gandalfiii]

I think you need to start with more pre-boil volume. Maybe between 7.5 to 8 gallons pre-boil to get 5 into the fermenter depending on your boil off rate. I always try to start with 7.5 for 5 gallons with a 60 minute boil.

 

[Chefjp]

Why did you go for 90 minutes? Did you also account for evaporation for the additional half hour? If you compensated for that you wouldn't have to add so much top off water and your gravity would be a little higher. I don't have beersmith in front of my but 1.055 seems a bit on the low end for 11lbs of pale malt, but I could be wrong.

I boiled for 90 min because that was the recipe for stone ipa from byo

 

[a6ladd]

Roger that. Ive done a few 90 minute boils before and there is a great amount of wort lost due to evaporation. Did you take that into account? I actually preferred the 90 minute boil sometimes; I added a low AA% hop for a bittering addition to an RIS I brewed up, it was the perfect amount of bitterness.

I think gr8shandini might be right on with his advice, try giving it a good stir. The wort may have become stratified. Temperature correction is also important with hydrometer readings.

 

[duboman]

If your equipment profile and recipe did not account for a 90 minute boil than you wound up under volume, hence the need to top off. By topping off you then diluted your beer and got a lower OG.

 

[TopherM]

It could be something as simple as a bad grain crush. Did your grains look like all of the grains were at least cracked?

 

[duboman]

It could be something as simple as a bad grain crush. Did your grains look like all of the grains were at least cracked?

The OP stated thy his pre boil gravity was spot on so his mash efficiency was easily at least 80% so crush was probably no the issue, his OG issue comes into play post boil and top off

 

[Chefjp]

Im brewing another batch tomorrow, hope it goes better

 

[tre9er]

If your equipment profile and recipe did not account for a 90 minute boil than you wound up under volume, hence the need to top off. By topping off you then diluted your beer and got a lower OG.

Yeah but that doesn't add up. He concentrated the wort more and more as he boiled off. Adding a gallon back in dilutes it, but it was very concentrated at that time. Can't lose sugar when volume of water decreases from preboil.

 

[duboman]

Im brewing another batch tomorrow, hope it goes better

In preparation for tomorrow I would suggest you calibrate a stick to use to measure your volumes as you go into the kettle to verify your pre-boil volume. In addition, once the boil starts, drop the heat to get a nice rolling boil, not crazy splashing vigorous boil to minimize your boil off, allow to cool and then re-measure with your calibrated stick to check your post boil volume.

In addition, when you gather your first runnings measure your difference between strike water and what comes out so you can calculate your absorption by the grain.

While you are doing this be sure to note any wort left in your Mash tun as a loss and when you drain your kettle do the same. These numbers you can then enter into your equipment profile to be more accurate.

Take notes on all these items to really dial your system in so your next recipe volumes will calculate properly. Also, if you are close, but short volume in the primary understand that if you top off your OG will drop so evaluate the need for more beer or a beer at the gravity you want.

 

[tre9er]

Bottom line is next time take the OG before you add any top-off water. That will tell you the wort concentration and thus you can adjust the top-off accordingly.

Mix well, it seems that your sample was either taken above 60* when measured or wasn't mixed well after you topped-off.

 

[duboman]

Yeah but that doesn't add up. He concentrated the wort more and more as he boiled off. Adding a gallon back in dilutes it, but it was very concentrated at that time. Can't lose sugar when volume of water decreases from preboil.

True, but he never really gave us his true OG, only what was to be expected so this was my assumption that his OG was met somehow or greater and then the top off diluted and dropped it lower. Maybe I should just stop trying to read into things and assuming

 

[tre9er]

True, but he never really gave us his true OG, only what was to be expected so this was my assumption that his OG was met somehow or greater and then the top off diluted and dropped it lower. Maybe I should just stop trying to read into things and assuming

I guess what I'm saying is that what we do know:

6.79 gallons of wort collected afetr sparging with a preboil gravity of 1.055, both right on the money.

achieve[d] the 5 gallon volume

Means the gravity should have been higher than 1.055 by a significant margin.