Hops affect OG measurements?

[MartinV]

I've had some issues lately with my gravity, last week I brewed a batch of IPA, which by the way ended up having way to low gravity, 1.069 was expected, but when I did my measurements, the readings were 1.030, which totally freaked me out, I proceeded as usually with my boil and added the hops, when it cooled, made another reading, this one was 1.050, then I though that the hops residues may have affected the gravity, is this possible?, and is it better to make this measurements before the hops are added?

 

[smiller]

If you got a lot of the spent hop residue in your graduated cylinder, it should actually give you a higher reading. Was this batch AG or extract? If AG, was it the first time you used your system? Post your recipe.

 

[Yooper]

Hops debris shouldn't impact your Sg. The reason the first reading was so low as because of the temperature, I'm sure. If you didn't cool the sample, it would be very very low. If you cool the sample to 90 degrees or so, then you can use a correction table to get the corrected SG.

 

[smiller]

Ah, I bet that's ^^^ the problem. Just curious, Yooper, is the fact that the debris isn't in solution the reason it wouldn't affect SG?

 

[Yooper]

Ah, I bet that's ^^^ the problem. Just curious, Yooper, is the fact that the debris isn't in solution the reason it wouldn't affect SG?

Boy, I'm no scientist(!) but my understanding that the density tends to be a reflection of the amount of sugars in solution and that debris doesn't affect it at all. The only time I see an issue is when there are co2 bubbles in the sample (say, during fermentation) and the co2 bubbles can actually hold up the hydrometer. spinning the hydrometer to knock it off of the bubbles fixes that, though.

 

[sonex]

the reason your gravity between your pre boil and post boil went up is because you had boil off. you probably boiled off a gallon of liquid and left the sugars in the boil pot, B/C the sugar is denser the gravity goes up. hops does not change the gravity.

 

[RuffRider]

the reason your gravity between your pre boil and post boil went up is because you had boil off. you probably boiled off a gallon of liquid and left the sugars in the boil pot, B/C the sugar is denser the gravity goes up. hops does not change the gravity.

I agree. Also, on specific gravity, hop residue is not soluble in water or wort or any other liquid I know of. That's why it settles at the bottom of whatever container your wort is in. Therefore, it will not affect gravity readings.