Author Topic: How do you measure percentages of fermentable sugars?  (Read 692 times)

Offline syncopadence

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How do you measure percentages of fermentable sugars?
« on: May 29, 2015, 09:03:25 PM »
The question is the topic, but I'm looking to find out how to avoid overdoing it on the adjuncts.  According to Papazian, no more than 20% should be used (when using 2-row, anyway). I recently used 2.5g of chocolate in a stout, and while I think it'll be fine, I want to know how to figure out the exact amount I CAN add.
Thanks for any help!

Offline duboman

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Re: How do you measure percentages of fermentable sugars?
« Reply #1 on: May 29, 2015, 09:46:30 PM »
The question is the topic, but I'm looking to find out how to avoid overdoing it on the adjuncts.  According to Papazian, no more than 20% should be used (when using 2-row, anyway). I recently used 2.5g of chocolate in a stout, and while I think it'll be fine, I want to know how to figure out the exact amount I CAN add.
Thanks for any help!

Trying to figure out an exact amount IMO would be difficult as there are many factors that ultimately go into the ferment ability of any given grain and specialty malts simply based on their processing prove more difficult to determine.

When I create a recipe I try to think about the final product and what it brings to the table, then work backwards. I start with the base to determine starting gravity and then add in small amounts of specialty grains based on what characteristics they bring to the beer. Color, aroma, complexity, head retention, etc. I find less is more in most cases. Then figure out mash temps, overall body of the beer, yeast strain , etc.

This all comes with experience and tweaking recipes all the time to fine tune a given recipe. I'd like to think I nail things on the first try but rarely is that the case, there is usually something to improve.

It's always easier to add a bit of something than try to figure out how much to remove. Designing Great Beers is a great reference for learning recipes and ingredients as it provides many guidleines and percentages of grain types used in all styles of beer. You will find most have 2-5% given for any specialty grain, very rarely much more than that.

Long winded and not really answering your question but hopefully it helps:)
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Offline reverseapachemaster

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Re: How do you measure percentages of fermentable sugars?
« Reply #2 on: May 30, 2015, 03:37:04 PM »
The question is the topic, but I'm looking to find out how to avoid overdoing it on the adjuncts.  According to Papazian, no more than 20% should be used (when using 2-row, anyway). I recently used 2.5g of chocolate in a stout, and while I think it'll be fine, I want to know how to figure out the exact amount I CAN add.
Thanks for any help!

Are you asking about adding actual chocolate or chocolate malt?

When talking about grain additions there is no precise rule on what you can add or an upper limit on how much you can add. The question really depends upon what style of beer you are brewing, the particular grain in question and the rest of the recipe. For example, an Irish red ale might use an extremely small amount of black malt for color (often less than 1%) while a porter or stout might use several times what you would use in a red ale. However if your porter already had other dark grains then it may not be desirable to use any black malt.
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Offline a10t2

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Re: How do you measure percentages of fermentable sugars?
« Reply #3 on: May 30, 2015, 04:38:39 PM »
Clearing up some definitions… Adjuncts are ingredients that contribute starches but lack the enzymes to convert those starches into sugars in a mash. Rice, corn, oats, unmalted barley, etc. When using adjuncts, you need to make sure there are enough enzymes coming from the malt to convert both itself and the adjuncts. This is called "diastatic power".

20% is a pretty conservative recommendation, though maybe it was accurate in the 70s. With modern 2-row pale malts being so enzymatically active, you can use at least 60% adjuncts in the mash without issue. (Well, you might have trouble lautering, but you'll be fine on the enzymes.)

Chocolate wouldn't be an adjunct. I guess you could think of chocolate malt that way, but we generally just call that kind of thing a "specialty malt" or "character malt" or something like that. Specialty malts would never total 60% of a grain bill (and really shouldn't be more than 20% or so in most styles), so diastatic power just isn't an issue when working with a normal recipe.

To actually answer the question, home brewers usually work with extract in "point-gallons" and the potential extract of ingredients in "point-gallons per pound", which is almost never said/written correctly and generally abbreviated as ppg. If you look at the units, you can see that multiplying the pounds of an ingredient by its potential extract gives total extract in point-gallons. Divide that by the total extract of all the ingredients and you have the percentage of fermentables.

Or, much easier, divide the weight of the ingredient in question by the total weight of the grain bill to get pretty close.
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Offline syncopadence

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Re: How do you measure percentages of fermentable sugars?
« Reply #4 on: May 30, 2015, 10:49:44 PM »
It was actual chocolate, not chocolate malt. I added it to the boil toward the end just to melt it down. Think it'll be ok?

Offline a10t2

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Re: How do you measure percentages of fermentable sugars?
« Reply #5 on: May 30, 2015, 11:01:38 PM »
It was actual chocolate, not chocolate malt. I added it to the boil toward the end just to melt it down. Think it'll be ok?

At 2.5 g, you won't even notice it's there. I think people generally avoid actual chocolate because of the oils, but when I use cocoa powder I add it at flameout.
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Offline syncopadence

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Re: How do you measure percentages of fermentable sugars?
« Reply #6 on: May 31, 2015, 12:09:28 AM »
How much cocoa powder do you use (or would you use) for a 5 gallon batch? I've considered the idea before, but for whatever reason went a different route.

Offline a10t2

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Re: How do you measure percentages of fermentable sugars?
« Reply #7 on: May 31, 2015, 12:15:29 AM »
How much cocoa powder do you use (or would you use) for a 5 gallon batch? I've considered the idea before, but for whatever reason went a different route.

Anywhere from 50-150 g would be a good start, depending on how intense you want it.
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Offline syncopadence

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Re: How do you measure percentages of fermentable sugars?
« Reply #8 on: May 31, 2015, 12:20:30 AM »
Noted, thank you! Any recommendation on how much cocoa nibs to use in secondary (and length of time)? The batch in question is in primary right now.