Converting Batch Amounts
- Thread starter melinda
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Sorry, I'm a bit slow. If a 40L batch asks for 7kg of grain, then I go 7 divided by 40 and then times by 23 if I want a 23L batch. Does this also apply to the hops?
Cadbury
pokolbinguy
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Yes and yes. Well thats what I gather you do
t2000kw
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A brewing program will make it easier as previously mentioned, but if you just wanted to convert weights and measures, here's what you can do.
First, find your decimal multiplier by taking your desired batch size and divide by the recipe batch size.
Take this result and multiply it by every weight or measure you have. Two easy examples follow.
Let's say you want to brew a 25 litre batch and the recipe is 50 litres:
25/50 = 0.5
Multiply 0.5 times every item you have and you'll get half. It works with odd fractions, too, it's must easy to follow this example.
If you were to scale up a recipe, like you want to brew a 75 litre recipe but you have a 25 litre recipe:
75/25 = 3.0
Multiply 3 times every item in your recipe and you have your new batch.
For your 23 litre batch from a 25 litre recipe, you would multiply everything by 0.92. For your 23 litre batch from a 47 litre recipe, you would multiply everything by 0.49, or for all practical purposes, just double everything in this instance.
Doing it this way you don't have to use three numbers for each calculation.
For most brewing (at home), you won't have to figure a different hop utilization, but if you're taking a professional recipe on the order of several barrels and try to scale it down, the hopping rate will change considerably. I don't remember which way it needs to be adjusted, but for some reason or other in very large batches (compared to the typical home brewer's batch size), the amounts for hopping change and don't scale linearly.
ProMash (the brewing program I use) says this on the subject: " . . . very large kettles obtain a much higher utilization rate than very small kettles. Because of this, you may need to do some final tweaking to the hop bill."
And here's a link about this:
http://homebrewingadventures.blogspot.com/...nce-in-hop.html
Donald
First, find your decimal multiplier by taking your desired batch size and divide by the recipe batch size.
Take this result and multiply it by every weight or measure you have. Two easy examples follow.
Let's say you want to brew a 25 litre batch and the recipe is 50 litres:
25/50 = 0.5
Multiply 0.5 times every item you have and you'll get half. It works with odd fractions, too, it's must easy to follow this example.
If you were to scale up a recipe, like you want to brew a 75 litre recipe but you have a 25 litre recipe:
75/25 = 3.0
Multiply 3 times every item in your recipe and you have your new batch.
For your 23 litre batch from a 25 litre recipe, you would multiply everything by 0.92. For your 23 litre batch from a 47 litre recipe, you would multiply everything by 0.49, or for all practical purposes, just double everything in this instance.
Doing it this way you don't have to use three numbers for each calculation.
For most brewing (at home), you won't have to figure a different hop utilization, but if you're taking a professional recipe on the order of several barrels and try to scale it down, the hopping rate will change considerably. I don't remember which way it needs to be adjusted, but for some reason or other in very large batches (compared to the typical home brewer's batch size), the amounts for hopping change and don't scale linearly.
ProMash (the brewing program I use) says this on the subject: " . . . very large kettles obtain a much higher utilization rate than very small kettles. Because of this, you may need to do some final tweaking to the hop bill."
And here's a link about this:
http://homebrewingadventures.blogspot.com/...nce-in-hop.html
Donald
t2000kw
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Yep, I didn't mention that, and someone should, since this is a new person to AG brewing.
Too bad many recipes out there don't mention brewhouse efficiency. When they don't, you really don't know if what you end up with is what the original person (who wrote the recipe) had brewed. But if they at least provide OG and FG you can work backwards from this, or dilute (or boil down more) until you reach the same OG. If you end up with a higher FG, you can always dilute it on that end of the process, too (but I wouldn't boil it down once it's finished!).
But I have used a few of these and it seems that they turned out well. Not sure if I got the same exact beer or not, b ut I enjoyed it. I brewed this one a few times, never even measured the OG, and it turned out great!
http://brewery.org/cm3/recs/05_85.html
It seems like the Papazianism "Don't worry, have a homebrew" is a good general rule to follow (most of the time).
Donald
Yorg
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And not to forget that when your efficiency differs, you adjust your malt bill by adjusting the base malt, leaving the crystal malts/roasted malts the same - since you will get maximum extraction from these 'pre-mashed' grains regardless of the efficiency changing from 65% to 80%.
Am I right?
Am I right?
