How much extra space shall I calculate for mashing/boil and fermentation?

[Elysium]

I know that for mashing (no mashtun is involved, but a big 50 gallon tank will be my mashtun) I need to calculate the mash water and the amount of space the malts take up. Is there a general rule as to how much space (in gallons) the malt occupies per lb?

Then the other thing I am not sure about is how much head space shall I leave for the boil? I know it is highly dependent on the strength of the boil, but is there again a general rule?

And last but not least....the fermentation. Here everything depends on how active the fermentation is...but is there a general rule here too in X% or gallons?

UPDATE: just got a message from the provider of the conical fermentors. He advised me to leave 25% headspace for ales and 50% for wheat beers. I am still researching the headspace for mashing and boiling.

 

[Hex23]

I know that for mashing I need to calculate the mash water and the amount of space the malts take up. Is there a general rule as to how much space (in gallons) the malt occupies per lb?

Then the other thing I am not sure about is how much head space shall I leave for the boil? I know it is highly dependent on the strength of the boil, but is there again a general rule?

And last but not least....the fermentation. Here everything depends on how active the fermentation is...but is there a general rule here too in X% or gallons?

For the first question, I think you'll find the answer here: https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/ more generally post 11.

On the second topic, you can hardly go wrong by using a BK twice the size of your initial boil volume (often 7 gallons for a 5 gallon batch) - you'd have to try hard to get that to boil over. I used to do 5 gallon batches (even 90 min boils) in an 8 gallon BK and while it's possible, you have to be very careful.

I'd say at least 20% headspace in the fermenter, especially for aggressive yeasts, and even there you're going to want a blowoff tube. In a secondary fermenter, you'd generally want as little headspace as is practical.

 

[BigDog007]

Beersmith defaulted to .5gal/hr, I was curious so I did a full 60 minute boil and found that my actual boil off was 1gal/hr which is obviously a big difference. Once I reached a strong rolling boil I turned the flame down to a point where it gave me a nice consistent rolling boil. I'm not sure if this is scientific in any way but it made me feel a lot better knowing for sure how much I can expect to boil off. I just did this tonight and now I'm cooling to see how much actual cooling shrink I get. I assume once I have this data and follow a similar method on an actual boil with wort I should come close to a finished 5 gallon batch when I'm done. I only have an 8 gallon kettle right now but it seemed sufficient, the next step up at my LHBS was a 15 gallon and it just seemed so excessive for a 5 gallon batch.

 

[ChelisHubby]

For a boil pot I use a ten gallon kettle, for a carboy I am using a 6 gallon size as it fits my swamp cooler nicely. but boil overs can still happen and blow off tube is still good insurance. That said I try to fill the carboy with all of the boiled wort. and if it fills the carboy all the better and if I lose a small amount of beer thru the blow off I am happy. I know I have gotten as much as was possible from that brew.

 

[Gnomebrewer]

For the boil, I find that the kettle should be twice the final volume. I do mostly 26L batches in a 50L kettle, pre-boil volume is about 36L. I've never had a boilover, but it goes close. So that's 33% headspace.

For the fermenter, 20% headspace is normally good, but some yeasts (especially wheat yeasts like WY3068, and also Notty) will still need a blow off tube with 20% headspace.

 

[muels]

http://www.rackers.org/calcs.shtml

This should help, bunch of calculators.


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