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Calculator and Efficiency

Post #1 made 14 years ago
by the_mc
So I have done 5 recipes now with the calculator and on each one I have been over my target OG by ~10 points consistently. The brewlength has been correct for all of them. I have the efficiency set at 80% should I be raising it?
Last edited by the_mc on 16 Jul 2011, 01:15, edited 1 time in total.

Post #2 made 14 years ago
by stux
How have your volumes been?

Have you got your numbers in a spreadsheet?
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #3 made 14 years ago
by the_mc
stux wrote:How have your volumes been?

Have you got your numbers in a spreadsheet?
The volumes have been right on the money or even a bit high in a few batchs. I attached the last sheet I used.
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Last edited by the_mc on 16 Jul 2011, 01:15, edited 5 times in total.

Post #4 made 14 years ago
by PistolPatch
Hi there mc,

When you say you have been over your target by 10 points consistently, I haven't seen this in your prior posts. Your first brew (a heavy beer) was spot on in 'Into Packaging Efficiency' (what was reported here) though you had more wort at less gravity. Your second was 10 gravity points over but you said this was due to your conversion to pounds from kilograms. Another heavy brew was 23% over-efficient which equated to over 20 gravity points. In the sheet attached here it is 5 points over. So, I know of 4 out of 5 results and I'm not seeing a reliable trend here yet old mate ;) :P .

Lots of enthusiasm though and it's great to see you wanting to get this sorted - good on you :thumbs:. You managed to get those 5 brews under your belt pretty quickly too :P. Some of them were pretty heavy or complicated beers so you are certainly "jumping in".

Here is what I would do...

1. Change your efficiency to 85% as that is what I get (on average, not each brew) using the same size pot and volumes as yourself.

2. You have calibrated your hydro - good on you! Is your hydro jar wide enough though or is it sticking to the sides of the jar?

3. How many readings are you taking during the brew? Do pre-boil, post-boil and then take another just to check straight after you aerate your wort. (Also measure the kettle trub and volume into fermenter at this point). It is really important to do this many readings when starting out. It 'accelerates' obtaining a reliable average as it gives you 15 readings over 5 brews instead of just 5.

4. Are you chilling your 'hot' wort samples correctly? In other words are you chilling your sample to 15 c or 20 c (depending on your hydro).

5. Are you covering your hot samples with plastic wrap as they cool?

6. Are you able to double-check the weight of your grain bill in some way?

7. Did some of your grain bills contain grains with potential yield that is a bit out of the normal range?

I think the taking of three readings (and writing them down) is going to be the real solution here mc so go for it! You'll have all this sorted in no time.

Congrats again on getting those first 5 under your belt.

:champ:
PP
Last edited by PistolPatch on 16 Jul 2011, 05:37, edited 5 times in total.
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Post #5 made 14 years ago
by the_mc
PistolPatch wrote:Hi there mc,

When you say you have been over your target by 10 points consistently, I haven't seen this in your prior posts. Your first brew (a heavy beer) was spot on in 'Into Packaging Efficiency' (what was reported here) though you had more wort at less gravity. Your second was 10 gravity points over but you said this was due to your conversion to pounds from kilograms. Another heavy brew was 23% over-efficient which equated to over 20 gravity points. In the sheet attached here it is 5 points over. So, I know of 2 out of 5 results and I'm not seeing a reliable trend here yet old mate ;) :P .

Lots of enthusiasm though and it's great to see you wanting to get this sorted - good on you :thumbs:. You managed to get those 5 brews under your belt pretty quickly too :P. Some of them were pretty heavy or complicated beers so you are certainly "jumping in".

Here is what I would do...

1. Change your efficiency to 85% as that is what I get (on average, not each brew) using the same size pot and volumes as yourself.

2. You have calibrated your hydro - good on you! Is your hydro jar wide enough though or is it sticking to the sides of the jar?

3. How many readings are you taking during the brew? Do pre-boil, post-boil and then take another just to check straight after you aerate your wort. (Also measure the kettle trub and volume into fermenter at this point). It is really important to do this many readings when starting out. It 'accelerates' obtaining a reliable average as it gives you 15 readings over 5 brews instead of just 5.

4. Are you chilling your 'hot' wort samples correctly? In other words are you chilling your sample to 15 c or 20 c (depending on your hydro).

5. Are you covering your hot samples with plastic wrap as they cool?

6. Are you able to double-check the weight of your grain bill in some way?

7. Did some of your grain bills contain grains with potential yield that is a bit out of the normal range?

I think the taking of three readings (and writing them down) is going to be the real solution here mc so go for it! You'll have all this sorted in no time.

Congrats again on getting those first 5 under your belt.

:champ:
PP
Thanks pistol. The SG was 5 over the OG was 7....but I would agree there is something going on. I do know that I was 20 over for the one batch due to the grain bill, but the other 4 have all been over between 7 to 10. I will try 85% and see if I am closer.

To answer some of your questions:

- Hydro jar is wide enough. No touching :) never would have thought of that though!
- Only taking 2 readings. Pre-boil and post boil. I will take one more next time.
- Using a chiller to get the wort down to 20 in 10 min then taking the OG
- For the SG I have been using the temperature adjusted table in "Designing Great Beers" instead of chilling it.
- No way to double check the weight of the grain bill as I only have one scale but it is accurate I have checked :)
- I will double check to see if I used any high yield grains since I just finished that chapter in "Designing Great Beers"

Thanks again for the feedback. I am sure it is likely a consistency issue on my part but I want to explore all avenues!
Last edited by the_mc on 16 Jul 2011, 07:09, edited 5 times in total.

Post #6 made 14 years ago
by PistolPatch
mc, I see I made a typo in my last post (now fixed). I should have said I know 4 out of the 5 results of your brews from following your forum posts. This might be worth checking as those posts reflect my post above. It is not uncommon when you start analysing figures etc in hindsight to bugger them up - sometimes I have trouble understanding my notes the following day :scratch: :lol:.

So, your prior forum posts might provide a more accurate historical interpretation :P. Maybe.

I'm really sceptical of adjusting hydrometer samples for temperatures that are way out of ambient range. There is actually no need to get an instant gravity reading during a brew so when taking a pre-boil or post-boil sample...

1. Stop the flame, mix up the wort and dip a mug into the wort.
2. Cover the sample with wrap to avoid evaporation (concentration) of the sample.
3. Re-light your flame if it is a pre-boil reading.
4. Put the sample in the freezer for a while or a water bath.
5. Get it to 15 C or 20 C.
6. Take your reading.

For a final OG reading (a double-check to your post-boil one) take the sample with a sterilised mug just after aerating the wort so as you know the wort is well mixed. (Measuring both the trub and volume into fermenter also acts as a double-check on the previous two efficiency readings.)

Many hydrometers can actually break at even mash temperatures so take the readings when the sample is cool.

Remember also that the current calculator expects you to convert your hot pre and post-boil volumes to their ambient equivalent. The 'straight-sided helper' section is pretty confusing so just make sure you multiply hot volumes by 0.96 to get their ambient equivalent.

Also, don't expect your efficiencies to match on every brew. Be happy with a 4% variance either way and the occassional, 'WTF!' reading.

It's all fun :P ,
PP
Last edited by PistolPatch on 16 Jul 2011, 08:44, edited 5 times in total.
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Post #7 made 14 years ago
by stux
Although hydrometer adjustment tables are good, they are less accurate at high temperatures. I wouldn't trust any reading taken above 60C

Generally I'll wait for the sample to get below 50C before using a calculator to adjust it back to 20, and then I will double check it at 40C

I find at 50 or 40C I get accurate results
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #8 made 14 years ago
by stux
For the record, I generally get 83% or higher, even up to 97%!
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12
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