Topping off fermenter - All Grain

[firechill]

Hey all. I just recently got into all grain brewing and I have possibly a dumb question. I know that when you are brewing with extract, you can do a boil of say 3.5 gallons and then top off the fermenter to 5 gallons.

With all grain, is it possible to do similar with the BIAB style? I.E. boil and add 4 gallons of wort to fermenter and then top it off to 5 gallons with water? I appreciate any advice.. My kettle is maybe 6 gallons.

Thanks!

 

[Golddiggie]

You could, or you could just use a 5 gallon carboy and make 4 gallon batches. I topped off my only partial mash batch and then swore to never do that again. Whatever I end up with for post-boil volume is what I use for that batch. Luckily, I've not had too little again (that was the only time I used two pots to boil)...

With a 6 gallon kettle (best to measure the volume to make sure you know how much it holds, rather than guessing) you could do a slower boil with the maximum amount of wort. IF you want, you could use fermcap to control the foam during the boil. Or just go with slightly smaller batch sizes until you do get a larger kettle... I would advise getting at least a 30-32qt kettle for all grain [5 gallon] batches.

One of the biggest issues with topping off an all grain batch (the way I see it) is you need to mix the hell out of it in order to get it to fully combine. IMO, a total PITA process. Hernia in a bottle...

 

[firechill]

Appreciate it! I think I will stick with smaller batches for now until I can get a larger kettle.

 

[Golddiggie]

I think it's a solid option... Just means you can get to the same point (for the finished batch) without using as much grain.

That being said, I do enjoy being able to ferment ~5 gallons at a time.

If you're looking for an economical way to get the larger kettle, consider building it with an aluminum stock pot. That's what I used for mine. Got it from a restaurant supplier for cheap money. Installed the ball valve myself and been rocking and rolling ever since. LOVE being able to just use the tubing to transfer the wort from the kettle to the primary. With a little gravity assistance, and getting the hose positioned right, you can get good aeration at the same time. Especially with a 1/2" ball valve. I wouldn't go with anything smaller in the kettle...

 

[kpr121]

Does the yeast activity in the fermenter agitate the wort enough to get a thorough mix? Or will the top up water still stay segregated?

 

[Golddiggie]

The fermentation process will complete the mixing of the top-off water and wort. But, you won't have a guaranteed accurate OG reading without going through a lot of effort to get the two fluids mixed.

I suppose, you could add the extra water to the batch in the final minutes of the boil (have the water already at boiling temperatures). That could get it to mix fully, and give you close enough to 5 gallons of wort to ferment. IMO, that's more work when you don't need it...

Nothing wrong with fermenting a little less for a batch size, due to the kettle being smaller than you need for a full batch boil.

Pretty sure I was able to build my current 5 gallon batch kettle (8 gallon capacity) for under $75... That includes the pot, lid, and valve assembly. The kettle/pot has 4mm thick sides (base too I believe, although that could be thicker)... Love how aluminum cools down with the wort damned fast.