Author Topic: In case you wonder about differences in efficiency calculations  (Read 901 times)

Online Kaiser

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In case you wonder about differences in efficiency calculations
« on: January 11, 2010, 01:20:22 PM »
Here is something that I wanted to write about for a while: the differences between the 2 different types of efficiency calculation that are in use by brewers.

I use the Plato based one in all my spreadsheets while most other home brewers use the gravity point and ppg based one. While I found that there is much less difference than I initially expected it is an interesting exercise in using the Plato definition and its relationship to the specific gravity. It also shows how the ppg values for sugar and malt can be derived from their respective extract potential given in %. It's pretty math heavy though. Nothing really bad but a lot of different variables that need to be tracked.

Differences in Efficiency Calculations

Conclusions

Does it really matter in brewing whether you use the ppg based forumla or the Plato based one? Not really. If you always use the same formula for efficiency calculation and subsequent recipe design it doesn't matter at all. It may matter when discussing and comparing efficiency with other brewers. In this case the ppg based approach is within 1% of the actual efficiency for all realistic gravities. That error, however, is too small to be a conern in home brewing. Using the % based efficiency calculation with a crude sg to Plato conversion, on the other hand, can overestimate efficiency significantly. Thus care needs to be taken when converting Plato or Brix readings into specific gravity readings. That is in particular true for high gravity worts.

Kai


Offline trickydick

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Re: In case you wonder about differences in efficiency calculations
« Reply #1 on: January 12, 2010, 05:53:02 PM »
Hi!

New the the AHA forum.  We needed this BADLY!

I think this thread would be the best spot to ask about about Mash Tun design.  I am planning to build a recirculation brew-stand this next year.

I've recently abandoned my 10 Gallon Rubbermaid cooler (glue has separated at the bottom and there is a upward bulge of the innner plastic liner which makes it impossible to use a false bottom).  I recently bought a Coleman Extreme 70 qt Cooler.  I have temporarily fitted it with my Bulkhead and ball valve connected to a Bazooka Mash Screen that I had used in the 10 gallon rubber maid.

I tried to build a manifold, but became frustrated.  I tried using 1/2 Copper tubing and fittings, but those I think  are too big for this cooler to build an optimal manifold.  I think I may try again with 3/* tubing.  Thought I could do 4  long collection tubes, but they would rest against the sides of the cooler because the fittings are sized such that any closer spacing isn's possible.

I don't think that the Bazooka Screen would support a RIMS/HERMS setup because of the same comments posted here concerning channeling - you would get non-uniform channeling of the wort feeding into the recirculation circuit, and likely also compaction of the grain I suspect because of the nature of the Bazooka Screen.

I could attempt to figure out the optimal design myself for a slotted bottom copper manifold design but I would rather tap into the knowledge and experience here to minimize further frustration, and maximize enjoyment (and efficiency).  So is there any awesome design I could copy, or is there any advice or blueprint that is out there for building a HERMS system with a Coleman 70qt Extreme cooler for a mash tun?

Thanks!

TD

Online Kaiser

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Re: In case you wonder about differences in efficiency calculations
« Reply #2 on: January 12, 2010, 09:17:26 PM »
I think this thread would be the best spot to ask about about Mash Tun design. 

Welcome!

How come? My blog post was a rather theoretical elaboration on two different ways of calculating efficiency.

This might be a better choice for a thread to reply to: http://www.homebrewersassociation.org/forum/index.php?topic=888.0

Kai

Offline Thirsty_Monk

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Re: In case you wonder about differences in efficiency calculations
« Reply #3 on: January 12, 2010, 09:39:50 PM »
Kai,

I think you got a typo in title:
Differences in Efficiency Calulations
http://braukaiser.com/lifetype2/index.php?op=ViewArticle&articleId=133&blogId=1
Na Zdravie

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Online Kaiser

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Re: In case you wonder about differences in efficiency calculations
« Reply #4 on: January 12, 2010, 10:30:27 PM »
Thanks. I'll fix that.

Kai