Brew Volume

[Wfu1bunn]

Brewed an IPA the other day. Recipe called for collecting 6.5 gals of wort which I did and boiled for 90 minutes. Only collected 3 gals when done and had to add 2 gals of water (5 gal batch).

Questions:
1) adding so much water has to affect gravity right?
2) what can I do to collect more after brewing or is that how it is?

Thanks for any help.

 

[Dgallo]

Brewed an IPA the other day. Recipe called for collecting 6.5 gals of wort which I did and boiled for 90 minutes. Only collected 3 gals when done and had to add 2 gals of water (5 gal batch).

Questions:
1) adding so much water has to affect gravity right?
2) what can I do to collect more after brewing or is that how it is?

Thanks for any help.

Was your recipe all grain or extract?

if your 90 minute boil was roaring and your pot is shallow and wide, that is what caused such boil off. Topping off your water is fine and it will cause a drop in your og because the post boil wort is become less concentrated as you add water. This is not good or bad in itself, all depends on what you’re targeting, you just have to add the correct amount of water to hit your targeted og

To collect more, boil for only 60 minutes and have it only be a rolling boil and invest in a pot that is shaped for a better boil off rate

 

[Wfu1bunn]

Thanks for the reply. It was all grain. Brewed in 15 gal blinchmann brew kettle.

 

[Dgallo]

Thanks for the reply. It was all grain. Brewed in 15 gal blinchmann brew kettle.

Ok they have the proper size ratio for boil off rate, so you must have boiled to vigorously and for too long. Here’s a great quick video of reference for boil types. I personally use around L2/L3 and boil of around a gallon within an hour

 

[IslandLizard]

What he says! ^
You don't even need (or want) a rolling boil. A mere simmer (surface rippling) is plenty.

6.5 gallons pre-boil
- 1 gallon boil off (1 hour)
- 0.25-0.5 gallon left in kettle with trub
= 5-5.25 gallons in fermenter.

If you dry hop you may want to aim at 5.25-5.5 gallons in the fermenter, allowing for 1-2 quarts to be left behind with the yeast and hop trub.

 

[kevin58]

The numbers posted above for losses may work for islandlizard but you really need to measure your losses on your system yourself. You may lose more than 1 gallon in 1 hour in the boil. Same with loss to trub. If you use pumps and a plate or counterflow chiller you will have some loss here too as well as in your hoses. Once you've identified and measured all of these losses you can factor them in to your pre boil volume calculation to end up with exactly what you want into the fermenter.

Side note: if your post boil OG was on target I would much rather end up with a smaller volume of the beer I intended than dilute it and have a watery beer.