2.5 Gallon versus 5 Gallon Boil?

[jc03]

I just brewed my first 5 gallon batch (Irish Red Ale that came in my Northern Brewer Kit). It called for 2.5 gallons of water and then to top off the carboy to 5 gallons. Is there a benefit to doing the boil with a full 5 gallons so there is no topping off? What are the pros/cons? Thanks.

 

[thadass]

From http://www.northernbrewer.com/connect/2011/08/full-vs-partial-wort-boil/ :

Partial Volume Boil – Boiling a concentrated wort and diluting with water after the boil to reach full volume


Pros -

Boils can easily be done on a stove top
Can be done in 3-4 gallon kettle
Reduces the amount of time needed to bring to a boil
Wort chilling times reduced with less volume


Cons -

Concentrated wort reduces hop extraction efficiency, more hops are needed to reach bitterness levels of full wort boil(approx. 10-25%)
Boil overs can be more difficult to clean up
Increased wort darkening occurs in concentrated wort boils
All grain brewing requires a full wort boil


Full Volume Boil – Starting with 6 or more gallons and boiling down to a 5 gallon batch size

Pros -

Increased hop utilization over partial volume boil
less wort darkening
Ability to brew all grain batches


Cons -

Can be difficult to boil 5+ gallons on stove
Requires 7.5+ gallon kettle
May require alternative heat source
Additional chill time or use of wort chiller needed
Increased time to bring to a boil

The main cons in a full volume boil is that it takes longer to heat up, and longer to cool down (and extra equipment is required for both parts). The pros are as stated above: hop utilization, color, etc.

The fact that all grain is almost always full-volume isn't really a pro or a con to me, it's just a technicality. You could technically do a partial-volume all-grain brew, it's just not very common.

 

[jc03]

Thanks!

 

[pricelessbrewing]

What about dividing the recipe in two and doing two 2.5 boils? Seems like it would be a happy medium. Get full hop utilization and most of the effort is in time and babysitting so it's not really duplication of effort for equal results imo.

 

[jc03]

I've been "watching the pot" for 15 minutes on a test run with 6 gallons on my induction cooktop. I'm not sure it's going to boil. Is there a benefit to boil say 4 gallons versus the 2.5 that my racer 5 clone prescribes? I think my stove can get that done. Is it a problem if I put the lid on the kettle to get it started? Thanks.

 

[Terry_Plow]

I've been "watching the pot" for 15 minutes on a test run with 6 gallons on my induction cooktop. I'm not sure it's going to boil. Is there a benefit to boil say 4 gallons versus the 2.5 that my racer 5 clone prescribes? I think my stove can get that done. Is it a problem if I put the lid on the kettle to get it started? Thanks.

I'm wondering the same thing. I don't have a wort chiller, so I'm trying to find the happy medium of 2.5 - 5 gallon boils.

 

[ericbw]

I've been "watching the pot" for 15 minutes on a test run with 6 gallons on my induction cooktop. I'm not sure it's going to boil. Is there a benefit to boil say 4 gallons versus the 2.5 that my racer 5 clone prescribes? I think my stove can get that done. Is it a problem if I put the lid on the kettle to get it started? Thanks.

There's a benefit, but you have to be sure you understand the hop utilization. If a recipe was formulated (and tweaked, perfected, etc.) with a certain boil size, then you'd have to adjust the hops for the new size to end up with the exact same result. In theory.

I do put the lid on in the beginning to get it going but then keep it uncovered.