Boil Water Volume Question

New to brewing, just purchased a starter equipment kit and a Brewers Best English Brown Ale kit. The instructions on the BB kit say to use a boil volume of 2 gallons. After reading some threads on this forum and the book by Palmer, this volume seems a little low. Is there a problem with increasing the boil volume to 3-4 gallons, or would this mess things up. Maybe I am wrong but by my thinking, increasing the boil volume will allow more of the extracts/hops/grains to be dissolved? What do you think?

My advice: brew your kit exactly according to the directions. You'll have a mush easier time coolling those 2 gallons than you would a larger boil, and your recipe is formulated for a 2 galllon boil.

Here's why it matters in recipe formulation: the higher the specific gravity (concentration of sugars in the wort), the lower the efficiency of extraction of bittering compounds from the hops.

So, a larger boil means a lower gravity wort, which means you'll extract more bittering compounds from the same amount ot hops.

You can use the free Beer Recipator software to play with these numbers

http://hbd.org/cgi-bin/recipator/recipator

But any improvement you could make in your kit's quality would be negligable. Just brew it according to the directions and concentrate on getting comfortable with the process.

Be careful changing up the boil amount without adjusting hop additions...

The hop additions in the recipe are based on the 2.0gal boil so you'll reach the target IBU for the recipe by following the recipe. If you boil more water (lower gravity of the boil) the hop utilization will be better, thus you will have a higher IBU result.

Maybe you want that, maybe you don't...

Some brewing software (I recommend BeerSmith for a one-time cost of 19.95) would be helpful in adjusting the recipe if you want to do a full boil. A full boil is a great idea, but changing it (boil amount) without changing the hop additions could have an adverse effect in some cases.

EXAMPLE:

Recipe:
7.5 lb. Liquid Extract for a 5 Gallon Recipe = OG of ~1.055
1oz. Chinook 12%AA Hops for 60 Mins
1oz. Cascade Hops 5.5%AA for 30 Mins
.5oz Cascard Hops 5.5%AA for 5 Mins

This recipe, if done full boil (5.5 gallons taking into consideration boil off), would result in ~58 IBU of bitterness due to the good utilization rate of the hops (per Beersmith software).

The recipe if done 4 gallon oil would have some reduced IBU level. I didn't calculate for this volume, but I'm guessing ~40IBU.

If you reduce the boil for the exact same recipe to 2.0 gallons and use 3 gallons top off water at the end, you will achieve ~20-22 IBU of bitterness due to the lesser utilization (more extract/sugars/etc in less water = less room for the bitter hop oils to absorb into the wort) of the hops in the smaller boil.

You will almost definitely notice a difference between 20 and 58 IBU brews...

Simple answer to your original question is to follow the recipe exactly (boil size and hop additions especially) unless you have brewing software (or do a manual recalc of IBU) to correct the recipe appropriately.

Hope this helps.

Go exactly by the instructions. I did a kit the other day that was very similar, saying to boil 2 gallons. I ended up misreading the instructions and boiling 2.5 gallons, and my wort ended up being about .005 low.

Not only is following the instructions important on a kit for the reasons cited by others above, but smaller boil amounts are a good way to start as a new brewer. The smaller boil is easier to manage, easier to cool, easier to pour, ect... Most of the people doing larger boils are all-grain brewers, where full boil is a requirement.

I've been brewing for over 13 years and I still only boil 1.5 gals, use only DME 99% of the time, and only seldom use over 1.5 oz of hops in my boils. Most of the time it's only 1.1 oz of whole hops...obviously not a hop head.

Wow, that was quick! Thanks for the information.