15L Fermenter to make 23 L brew?

[trustyrusty]

Hi I was given a 15 litre FV (for someone else to use)
Kits make 23 litres, would it possible to fill up bottles about 420 ml and then top up with water to make the volume (im sure how some breweries increase capacity?)

Thanks

 

[Coalface]

You could do it, boil the water first though to kill any potential bacteria, and decrease the dissolved oxygen.

 

[trustyrusty]

You could do it, boil the water first though to kill any potential bacteria, and decrease the dissolved oxygen.

Thanks I was thinking that.. Its probably something should do with every brew but a hassle to boil 23 litres each brew...

 

[MHB]

If you used the kit in a 15L brew and wound back your "sugar" addition; you would get close to normal strength beer. The bitterness will be a higher. If you chose a less bitter kit it shouldn’t be too far out of bounds.
You could do a bit of brewmaths or consult a calculator that will get you close as will just proportioning the additions.
Say you would normally brew a 1.7kg kit and 1kg of dextrose to 23L.
A 1.7kg kit and a hundred grams of Dex would be close.
Mark

 

[trustyrusty]

I calculated that wort would be 420 ml and the rest of the 750ml water, why cant I do the usual brew in the 15 and then make with water at the end in the bottle, ? I am not turn a 23 litre in 15 litre, if that is what you mean?

 

[MHB]

It’s called High or Over Gravity Brewing. If you go over about 20% over gravity, there will be very noticeable changes in the flavour of the beer.
What you’re proposing would be ~44% over gravity.
Your OG would move from around1.040 to 1.060 (given K&K 1kg Dex) for a pretty standard ~4.5%ABV beer. Probably not as far out of bounds as a big brewer would be aiming at (think OG1.080) so you might get away with it.

The big concern is your diluting water; it must be Oxygen, Chlorine, bacteria and other contaminant free.
For a one off trial I would use an off the shelf purified water (Pura is one of the best available in 5&10L bag in box at supermarkets).
A nice quick way to measure your diluting water into bottles would make life easier.
Other option is to get a bigger fermenter, a bucket tap and some gladwrap should leave you change out of $20 so meh - whatever works for you.
Mark

 

[trustyrusty]

It’s called High or Over Gravity Brewing. If you go over about 20% over gravity, there will be very noticeable changes in the flavour of the beer.
What you’re proposing would be ~44% over gravity.
Your OG would move from around1.040 to 1.060 (given K&K 1kg Dex) for a pretty standard ~4.5%ABV beer. Probably not as far out of bounds as a big brewer would be aiming at (think OG1.080) so you might get away with it.

The big concern is your diluting water; it must be Oxygen, Chlorine, bacteria and other contaminant free.
For a one off trial I would use an off the shelf purified water (Pura is one of the best available in 5&10L bag in box at supermarkets).
A nice quick way to measure your diluting water into bottles would make life easier.
Other option is to get a bigger fermenter, a bucket tap and some gladwrap should leave you change out of $20 so meh - whatever works for you.
Mark

Ok thank you