What affects gravities?

[PFDarkside]

What affects the OG of a kit beer? It's a premeasured amount of extract, so that can't matter... Does the specialty grain steeping time/temerature make a difference? How about total boil time? Can you boil off extract? Does it make a difference how much water is in the boil? (2.5 gallons vs. 3.5 gallons for example?)

Educate me. :)

[YamahaXS]

higher concentration of sugars and other solubles results in a higher gravity


so if you use more extract, steep more grains, OR use less water you will increase the gravity.

[PFDarkside]

So all things being equal, if I do a 2.5 gallon boil and dillute with 2.5 gallons in the primary then it will be a OG than if I do a 3.5 gallon boil and dillute with 1.5 gallons?
What about people that do a full wort boil?

[stronk]

None of those should make any difference, as long as you don't lose too much water in the boil.

[S.F.B.]

Originally posted by PFDarkside
So all things being equal, if I do a 2.5 gallon boil and dillute with 2.5 gallons in the primary then it will be a OG than if I do a 3.5 gallon boil and dillute with 1.5 gallons?
What about people that do a full wort boil?

You will come out about the same. It doesn't matter haow much you boil. It is the final volume in the fermenter that you take your OG from. So, 2.5 boil with 2.5 dillution comes out the same as 3.5 boil with a 1.5 dillution. The sugars don't boil off.

[toneyc]

As for full volume boils, the OG stated in the recipe is for 5 gallons. I start with 6 to 6.5 gallons and I boil for an hour or so, which leaves me somewhere around 5 to 5.5 gallons of wort. With extract recipes, I should be pretty close to the OG stated in the recipe if I am pretty close to 5 gallons after all that. The reason we do full volume boils are for better hop utilization, and for less carmelization of the wort, resulting in lighter colored beer with more hops flavor.

:)
Toney.

[sylunt1]

The sugars in the wort contribute to the OG. As the sugars are consumed by the yeast - the gravity lowers. If you want to raise the OG add more sugars (honey, LME, DME, syrup, etc.) I would say that if you boil off water the gravity should raise (less water same amount of sugars). Steeping grains really shouldn't contribute much to the gravity as you are not getting sugars out (preforming a mash/sparge). Steeping specialty grains contributes to flavor and body. If you brew things with an OG over a 1.060 - make sure you oxygenate and I always pitch more yeast.