Batch size reduction?

[mlevings12]

So today I'm starting my first all grain brew. Going with a Coconut Porter. I only have a 4 gallon boil kettle though. Here's my thought. The local HBS store guy told me that for a 5 gallon batch all grain, I would need at least an 8 gal boil kettle. (8-5)/5=1.6 so the boil kettle needs to be 60% larger than your batch. Using this logic tells me I can do a 2.5 gallon all grain batch in a 4 gallon kettle. Anyone see any issues here? Thanks, Matt

 

[Yooper]

I used to do a 5 gallon batch (6.25 gallon boil) in a 7.5 gallon boil kettle.

You just need enough headspace to not boil over. Fermcap helps a lot with that!

You might be able to do a 2.5 gallon batch in a 4 gallon kettle, but you need to start with about 3.5 gallons of wort! That won't work. You could try having a second pot on a second burner, so that you can add wort as you boil down.

 

[bernerbrau]

Before I got my 6.5 gallon pot, I used to split the runnings into two 4-gallon pots and split the hop additions approximately half and half during the boil. I got a lot more wort reduction this way (more surface area + more heat = more evaporation), but it worked out well for someone on a budget. It's also a lot faster to boil this way if you're doing it on the stovetop. +1 on the Fermcap-S.

 

[mlevings12]

You might be able to do a 2.5 gallon batch in a 4 gallon kettle, but you need to start with about 3.5 gallons of wort! That won't work. You could try having a second pot on a second burner, so that you can add wort as you boil down.

Good idea. I have a second kettle, but it's ceramic. Is this going to hurt me at all?

 

[Yooper]

Good idea. I have a second kettle, but it's ceramic. Is this going to hurt me at all?

No- that should be ok!