(RESOLVED) Kettle dead space not coming into water reqs


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May 18, 2013
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Hi there,

When I adjust the kettle dead space in my equipment profile it doesn't seem to change the water requirements for a given target batch size, which isn't what I'd expect. Am I missing something?


Re: Kettle dead space not carrying through to water requirem

If you are using the quick water requirements from the recipe tools menu, the kettle dead space should change the overall water required.

If you are looking at the water requirements in a brew session, those are fixed when the brew is created. To update that, go to the brew session edit tab, then click rebuild brew.

As for the target batch size, that is left for you to define, and the water requirements works around that figure.

If none of that helps, please paste the results here so we can take a look. Maybe do a before and after, and let us know what values were used.
Re: Kettle dead space not carrying through to water requirem

Thanks for the very speedy response.

Here are the water requirements using the default equipment profile values in a recipe with 6lb of DME, 1lb of steeping grains and 5.5oz hops in a 60 minute boil:

Water Gallons Quarts
Target batch size 5 20
Grain absorption losses (steep / mash) -0.13 -0.5
Boil water added to kettle 6.48 25.9
Volume increase from sugar/extract (early additions) 0.16 0.6
Starting boil volume 6.64 26.6
Volume increase from sugar/extract (late additions) 0.31 1.2
Boil off losses -1.5 -6
Hops absorption losses -0.21 -0.8
Misc. losses -0.25 -1
Top off amount 0 0
Total: 6.61 26.5

When I edit my equipment profile and add 2Q of kettle dead space I get exactly the same numbers.

This is true both for a recipe and a brew session where I use the edit function to update.
Re: Kettle dead space not carrying through to water requirem

Okay, I see what is going on. You are doing a full boil in extract or partial mash mode.

Normally a smaller kettle is used with extract/PM brewing and people then top off the fermentor with water. In our system kettle dead space does not factor into those recipe modes.

Thankfully, the 'misc losses' option does factor in, so if you set that you should get the numbers you were expecting. The other option would be to convert the recipe to All Grain - the system will handle the extract additions just fine, and you will get more powerful brew log options.

Note that if your misc losses are a substantial percentage of the batch size (say more than 1-2%), the overall OG calculation will be off because the recipe editor is not presently aware of the misc losses. In that case, you will have to go with an All Grain recipe, and then set the batch size target to 'to the kettle'. We felt it was better to keep extract and partial mash as simple as possible, but in your case you have graduated to the next level!
Re: Kettle dead space not carrying through to water requirem

OK - good to know I wasn't missing something obvious!

If I change the recipe to all-grain but am actually doing an extract full-boil then I also have edit my equipment profile to remove all losses from my fictional mash - so set the lauter dead space and mash miscellaneous loss to zero. Now if I want to save a mixture of all-grain and full-boil extract recipes the profile will be wrong for one of the other of them.
Re: Kettle dead space not carrying through to water requirem

Our next release will allow for multiple equipment profiles, which will take care of that issue.
Re: Kettle dead space not carrying through to water requirem

So playing with this some more, I see a couple of issues:

- kettle dead-space is ignored in any extract recipe, so a 10G partial-boil batch in my 8G kettle ignores the dead space just like a 5G full-boil.

- changing between an extract and all-grain recipe deletes the steeping grains, and if I re-enter them as a fermentable in the all-grain version then they get deleted again if I change back to extract (for example, if I wanted to brew the partial boil version again).

All of this seems like a bit of a kludge; would it not be possible just to include the kettle dead space in extract recipe water calculations? Since the default is zero, partial boil brewers who simply pour the kettle contents into the fermentor would never know the difference!
Re: Kettle dead space not carrying through to water requirem

We can add support for kettle dead space in extract/partial mash in the water requirements section.

The larger issue is, the recipe editor 'batch size' will not account for these losses properly unless the batch size target is 'kettle'. However, that option is hidden for extract/partial mash as not to confuse beginners. We may need to enable this field with a profile option for brewers in your situation.

As for switching the recipe back and forth between All Grain and Extract, the simplest answer is to save two different recipes. The recipe copy feature will help speed that up. After all they are different beers, and this promotes the idea of keeping records of what you brewed.
Re: Kettle dead space not carrying through to water requirem

Adding the dead space ability for extract brews would be great - thanks.

I agree that a true all-grain recipe should be saved separately from an extract recipe, since they are indeed different recipes. However in this case the switch was a kludge simply to incorporate kettle dead space in an otherwise identical extract recipe. The fix will solve this though.
Re: Kettle dead space not carrying through to water requirem

In thinking about this, the simplest way to get the most accurate results while we are working on the upgrade:

Set your extract recipe's batch size to what you want to end up with in the kettle
Add the kettle dead space to the expected boil volume

Then you can mentally note that 2 quarts (or whatever it is), will be held back. Hops absorption is a factor in this too, but it isn't a huge amount.