Calculating Adjuncts

[Synthetase]

Hello all. Long time, no see.

As the thread title suggests, I have a question regarding the calculation of adjunct addition in all grain recipes. Namely, do you guys modify the adjunct addition to fit with the actual efficiency you got rather than the assumed?

For example, this recipe for Cooper's pale calls for 17.24% sugar, however, it assumes that brewhouse efficiency is 75%. Now, if you were to follow that recipe and only get an efficiency of, say, 60% and still added the same amount of sugar, clearly you're adding more than 17.24% sucrose since the final volume must be lowered to keep the SG the same. Do you compensate for this?

 

[bigfridge]

Hello all. Long time, no see.

As the thread title suggests, I have a question regarding the calculation of adjunct addition in all grain recipes. Namely, do you guys modify the adjunct addition to fit with the actual efficiency you got rather than the assumed?

For example, this recipe for Cooper's pale calls for 17.24% sugar, however, it assumes that brewhouse efficiency is 75%. Now, if you were to follow that recipe and only get an efficiency of, say, 60% and still added the same amount of sugar, clearly you're adding more than 17.24% sucrose since the final volume must be lowered to keep the SG the same. Do you compensate for this?

Yes, you have it correct.

You start at the fermenter with what volume and gravity you want and work backwards to give the amount of each fermentable required.

But in all honesty it won't make a whole lot of difference in the end so you can just ignore it if you like.

 

[Wolfy]

By calculating your ingredients as percentages you should be easily able to adjust for either efficiency or volume differences from the orignial recipe.
Most people should have a fair idea what their likely efficiency will be, so in general can make a good estimate of what's needed up-front.

Edit: If you've not brewed it already, you may also like to read through AndrewQLD's recipe thread here on AHB, in particular the more recent adjustments he has made: http://www.aussiehomebrewer.com/forum//ind...st&p=441916

 

[MHB]

Coopers Pale Ale Clone​

Type: All Grain

Date: 3/11/2005Batch Size: 6.08 gal

Brewer: Andrew ClarkBoil Size: 8.44 galAsst Brewer: Boil Time: 75 min Equipment: Stainless Brewery Taste Rating(out of 50): 48.0 Brewhouse Efficiency: 75.00Taste Notes: Light malt, dry and crisp with a good bitterness at the finish

Ingredients​

AmountItemType% or IBU6.61 lbPale Malt, Traditional Ale (Joe White) (3.0 SRM)Grain79.58 %0.22 lbWheat Malt, Malt Craft (Joe White) (1.8 SRM)Grain2.65 %0.04 lbCrystal, Dark (Joe White) (116.8 SRM)Grain0.53 %0.88 ozPride of Ringwood [10.00 %] (60 min)Hops26.1 IBU1.00 itemsWhirlfloc Tablet (Boil 15.0 min)Misc1.43 lbCane (Beet) Sugar (0.0 SRM)Sugar17.24 %1 PkgsCoopers Pale Ale (Coopers Bottle) [Starter 1000 ml]Yeast-Ale​

Beer Profile​

Est Original Gravity: 1.043 SG

Measured Original Gravity: 1.043 SGEst Final Gravity: 1.008 SGMeasured Final Gravity: 1.005 SGEstimated Alcohol by Vol: 4.56 % Actual Alcohol by Vol: 4.95 %Bitterness: 26.1 IBUCalories: 185 cal/pintEst Color: 4.0 SRMColor: Color

Interesting recipe, naturally no one in Australia is going to be using "Beet" sugar, good to see the recipe expressing ingredients as % of extract, rather than % of grist, makes the calcs really easy.
Working in Plato (P^o) makes it even easier and like Bigfridge said work backwards (Oh and you can completely ignore all that stuff in pounds shillings and pence).
Step 1; work out how much extract you need, let's say you want to knockout 22.5 L of wort and your kettle will retain 2.5 L of wort and trub, your making 25 L of wort at 1.043, convert that to P^o
(roughly SG= (P^o *4)/1000 +1 so P^o is 10.75, as Plato is simply %W/V the total amount of extract is 10.75=x/25, or 2.6875 Kg are dissolved in the whole 25 L of wort.
Step 2; doing the adjunct first 17.25% of the total extract is 2.6875 * .1724 = 0.463 Kg sugar.

Step 3 First grain 79.58 % of 2.6875 gives 2.139 Kg of extract from the base malt.

If the malt has a potential yield of 80% and your brewhouse efficiency was say 78% you end up with an equation that looks like this

2.139= (Kg Malt) * 80% * 78% rearranged Kg Malt = 2.139*1.2*1.22 = 3.9345 Kg Base Malt.
Step 3 is the same for the next malt and so on.

You get the % Yield from the COA (Certificate Of Analysis), its often expressed as % of a dry fine crush, then you find the coarse/fine difference and the moisture content and derive the CGAI (Coarse Grind As Is) value, if they don't give it in the COA, all malt sold in Australia is specified this way.

Christ I'm glad we work in metric it's just so dam easy.

MHB

 

[katzke]

My first question is if you know you have lower efficiency why would you think you would have to brew less?

Second question is if you know you are supposed to add a percent of sugar and your efficiency is lower then you know to use less sugar. The brew will of course have a lower gravity. That can be fixed by the answer to question number one.

Answer to first question is increasing the malt bill to compensate for your lower efficiency. You may not even need to as everyone has a different idea what efficiency is and I ignore it as much as possible. A good recipe will tell me how much beer it makes at what color, gravity, and bitterness. Even if you did not tell me how much beer it made I could figure it out with a malt bill.

That is why I use brewing software. Easy to play with the numbers. If you are a die-hard brewer you can figure it all out by hand.

Know if your efficiency was off then just finish the brew and figure what went wrong.

 

[Synthetase]

Thanks for the replies, guys. I'll be knocking out something based on that recipe today.

Katzke, the reason I'm asking the question is because I'm still in the early stages of all-grain and am never entirely sure what my efficiency is going to be like from one brew to the next. It's hard to estimate given that the AG beers I have made have been varied but mostly with high starting gravities so are not very efficient anyway. Therefore, to make sure everything is okay, I always take pre and post boil refractometer readings in order to adjust the hop bill and dilution water required.

 

[katzke]

Thanks for the replies, guys. I'll be knocking out something based on that recipe today.

Katzke, the reason I'm asking the question is because I'm still in the early stages of all-grain and am never entirely sure what my efficiency is going to be like from one brew to the next. It's hard to estimate given that the AG beers I have made have been varied but mostly with high starting gravities so are not very efficient anyway. Therefore, to make sure everything is okay, I always take pre and post boil refractometer readings in order to adjust the hop bill and dilution water required.

In that case plan on a lower efficiency when you calculate the recipe. Yes I calculate every recipe as systems are different and I want to make sure the results are what I expect. As a new brewer you should be doing the same. Also just because you find a recipe does not say it is correct. I have seen lots of recipes with impossible water volumes.

Then when you take pre boil gravity, if the gravity is higher then you expect for your system you can dilute if needed. For the first few brew sessions volumes will be off. It is all part of learning your brew system.

So to your original question. If your recipe requires the addition of sugar and your gravity is low you need to brew less beer and use less sugar. Follow the recipe and use the same percent. You could also have some dry malt on hand to boost the gravity. Either of these choices has disadvantages over getting the correct results for the recipe. None will be of such great effect at the home brew level.

Bottom line is enjoy the home brew experience.

If your efficiency does not improve as you brew more then you may have some technical issues. It could also be that you are not calculating efficiency correctly. All I worry about is how much sugar I get from the grain and how much wort I put in the fermentor. I then adjust the software I use to make sure it happens that way as often as possible.