Mash Gravity Figures Needed for BIABacus.

Post #1 made 6 years ago
On your next brew, if you are a pure BIAB'er and do a "mash-out", I'm wondering if you could take two gravity readings and record them here for us.

What is a Pure BIAB?

A pure BIAB is when all the water required in a brew is added to the mash. In other words, there is no active sparging involved.

What is A "Mash-Out"?

When BIAB'ing, you can either pull the bag at the end of the mash and then bring this 'sweet liquor' to the boil or you can allow the bag to remain in the sweet liquor and raise it's temperature to about 76 C - 78 C before removing the bag and then proceeding to the boil.

If you have a pulley set-up, doing a mash-out is easy. You can simply raise the bag so it is not touching the bottom of the kettle and apply heat with an occasional stir. Without a pulley, you will have to stir the whole time to prevent your bag being burned.

What Gravities Do We Need?

Could you please take two gravity readings for us...

1. Take one at the end of the normal mash.
2. Take one after you reach the mash-out temp.

Please post in this thread as follows...

Here are two examples for you...

EG 1. 60 minute mash followed by a mash-out.

Gravity at Mash End (60 minutes): 1.050
Gravity at Mash-Out (75 minutes): 1.055

EG 2. 90 minute mash followed by a mash-out.

Gravity at Mash End (90 minutes): 1.051
Gravity at Mash-Out (100 minutes): 1.053

(The above figures are fictitious so do not expect them.)

Be Careful when Taking Readings

1. Let your samples cool to 15 - 20 C. Hydrometer temperature corrections are not accurate.
2. Collect the sample in a coffee mug and cover it with plastic or foil whilst it cools. Use the fridge or freezer to speed up the cooling process.
3. Use a wide hydrometer jar. Most jars provided with commercially sold hydrometers are too narrow for accurate readings. Spin the hydrometer and take a few readings before making your final recording.
4. Post your figures even if they make no sense to you. Odd readings can occur for many reasons.

Why We Need Your Numbers.

The BIABacus has many formulas hidden within it to automatically estimate outcomes. Whilst all these estimates can be over-ridden, it is our aim is to get as many of these as accurate as possible. Good estimates help new brewers as well as saving experienced brewers doing unnecessary over-rides.

In this experiment, we expect an increase in gravity between the two readings for two reasons. Firstly, the grain has more contact time with the liquor. Secondly, the viscosity of the liquor increases at mash-out. We suspect that the former will be the major cause so please feel free to add in any other gravity measurements you can during the mash. For example, if doing a 90 minute mash, if you can record a gravity at 60 minutes, this would be very helpful.

Many thanks,
BB
Last edited by BIABrewer on 30 Sep 2012, 21:00, edited 2 times in total.

Post #2 made 6 years ago
Okay, here's how I went...

This was a pure BIAB with a mash-out).

My 'Temp-Corrected' Results

For practical purposes, I used a temperature correction tool on these readings. Most readings were taken at 32 C whereas my hydros are 15C ones.

Mash In plus 45 mins = 1.026
Mash In plus 60 mins = 1.038
Mash In plus 90 mins = 1.037

Raised to mash out Temp (this took 10 minutes)

Pulled bag at Mash In plus 110 mins = 1.044

Usually I see More Discrepancies

When I do take measurements on a brew, I do them very carefully and usually find a lot more discrepancies than I found on this brew. I can only see one discrepancy above so I think I got lucky on this brew.

Notes on Temp Correction

As a matter of interest, at the end of the boil, I did one reading of the same sample at both 32 C and 15 C and found almost a four point difference between the predicted adjusted reading and the 'real' reading (1.052 vs 1.056). I've seen this before so it would be interesting to see if anyone else finds discrepancies between temp adjusted readings and real ones.

Hope the above helps :peace:,
PP
Last edited by PistolPatch on 05 Oct 2012, 19:32, edited 2 times in total.
If you have found the above or anything else of value on BIABrewer.info, consider supporting us by getting some BIPs!
    • SVA Brewer With Over 100 Brews From Australia

Post #4 made 6 years ago
Notes:
-units are in "American", you'll have to convert to that funny metric system yourself
-pure BIAB (full volume, no sparge)
-gravity reading taken with a refractometer, each sample was drawn into a pipette and pipette cooled with tap water
-refractometer reads in brix, I used this to convert gravity readings

Here you go:

15 minutes: 7.4 brix/1.0282 (mash temp 154F)
30 minutes: 7.8 brix/1.0298 (mash temp 154F)
45 minutes: 8.6 brix/1.0329 (mash temp 154F)
60 minutes: 10.0 brix/1.0384 (mash temp 152F)
75 minutes: 10.5 brix/1.0404 (mash temp 150F)

I then ramped temp up to mashout (168F) over 15 minutes:

90 minutes: 11.2 brix/1.0432 (mash temp 168F)

I let it sit at mashout temp for 15 minutes:

105 minutes: 11.4 brix/1.0440 (mash temp 167F)

Pull bag and squeeze:

pre-boil: 11.5 brix/1.0444 (mash temp N/A)

So, it's only one set of data but it looks like the squeeze is a total waste of time other than getting my pre-boil volume where it needs to be (I only picked up .0004 gravity points). I think I'll just add a tiny bit more starting water and stop wasting my time squeezing!
Last edited by thughes on 07 Oct 2012, 08:28, edited 5 times in total.
WWBBD?
    • SVA Brewer With Over 100 Brews From United States of America

Post #5 made 6 years ago
By the way....taking readings every 15 minutes during the mash makes the mash time pass very quickly (and screws up my nap time).

I'm looking forward to seeing the numbers from someone that sparges.....
WWBBD?
    • SVA Brewer With Over 100 Brews From United States of America

Post #6 made 6 years ago
90 minute mash followed by a mash-out.

Gravity at Mash End (90 minutes): 1.031
Gravity at Mash-Out (100 minutes): 1.032
Why is everyone talking about "Cheese"
    • SVA Brewer With Over 50 Brews From Great Britain

Post #7 made 6 years ago
:scratch: My sg's dropped every reading. :idiot: cooled in fridge to app 20c readings were with refrac and 2 hydros. :interesting:
I'm joining Bob in the "take no readings camp". :evil:
lylo
AWOL

Post #8 made 6 years ago
Did a stove top brew tonight ("hob"...right?)

Notes:
-units are in "American", you'll have to convert to that funny metric system yourself
-pure BIAB (full volume, no sparge)
-gravity reading taken with a refractometer, each sample was drawn into a pipette and pipette cooled with tap water
-refractometer reads in brix, I had to convert gravity readings

Data:

end of 90 minute mash: 7.8 brix/1.0298
end of 10 minute mashout (168F): 9.0 brix/1.0345
pre-boil (after pulling and squeezing bag): 9.2 brix/1.0353


---Todd
WWBBD?
    • SVA Brewer With Over 100 Brews From United States of America

Post #10 made 6 years ago
Probably no useful info here but,

I did a brew a week ago and took some samples to check - end of mash, after mash out and after squeezing my bag.
I put them in the fridge and forgot all about them til about 2300 that night. (So, I took no readings until it was in the fermenter! )
I couldn't be bothered heating them up to 20° to take readings so I just tasted them and I was over the moon with how malty they tasted :D
Also , the samples tasted progressively sweeter but that could be my mind playing tricks on me.

Here is the recipe

Next time I'll take better readings
Last edited by housecat on 15 Oct 2012, 14:06, edited 2 times in total.
Part of the NoAd brewers

My mum says I'm cool.

Post #13 made 6 years ago
Gravity at mash end (90 min) 1.051
Gravity at mash out (110 min) 1.057

This is a high gravity beer Grain bill 9.2kg 24L into fermenter
Why is everyone talking about "Cheese"
    • SVA Brewer With Over 50 Brews From Great Britain

Post #14 made 6 years ago
Gravity at mash end (90 min) 1.046 (Measured once at 20C, 2 hydrometers)
Gravity at mash out (126 min) 1.056 (Measured twice at 20C, 2 hydrometers)

1.068 gravity beer (Grain bill 7kg + 500 grams Treacle syrup). 21L into fermenter
    • SVA Brewer With Over 100 Brews From Swaziland

Post #15 made 6 years ago
Doing a high gravity double IPA (1.083 estimated OG) 1.5 gallon stovetop test batch:

end of 90 minute mash: 1.052/13.4 brix
end of 10 minute mashout: 1.056/14.3 brix

2.5 kg grain, 7 litre into fermenter (how's that PP?)


Edit: hit 1.081/20.4 brix OG. :thumbs:
WWBBD?
    • SVA Brewer With Over 100 Brews From United States of America

Post #19 made 6 years ago
American ale

90min mash 1.045 SG

mash out @ 170F 10 min 1.047 SG
"All I know is that the beer is good and people clamor for it. OK, it's free and that has something to do with it."
Bobbrews
    • BME Brewer With Over 5 Brews From United States of America

Post #22 made 6 years ago
Im preparing to brew again this next Monday. :)

I provided my previous end of mash and mash out Specific Gravity, and plan to again. I just spent some time looking at the readings of others and it appears we are not all doing an identical process. Is this a big deal for the info that Biabicus needs?

I heated to mash out temps (170F) held for 10 min and pulled. It looks like some are heating to mashout and immediately pulling, and some I cant really tell. I want to give the info that will help.

How should I (we) mashout so that we are giving relevant info? :scratch:
"All I know is that the beer is good and people clamor for it. OK, it's free and that has something to do with it."
Bobbrews
    • BME Brewer With Over 5 Brews From United States of America

Post #23 made 6 years ago
[All posts above are excellent as they are. Please keep them coming. If you have time, please read the below as there may be even more that you can contribute.]

Thanks to all of you.

2trout's post is very timely. (More re your questions below trout.)

Thanks so much to you all for taking the time and trouble to contribute your numbers here. This is an extremely important thread and to see it being regularly bumped by you with no feedback or encouragement makes a massive difference.

We envision quite a few more of these style threads in the future. The aim of such threads is to improve or create new default information given on the site either in official threads or in the BIABcus. A lot of the research thinking we are doing or intend to do here has never been done before. The results will definitely end up being copied onto other sites and into other software, hopefully with acknowledgement or permission, so, what you are doing here will make a big difference.

It's a very important thread.

In this thread, we are exploring the most basic of mash parameters. Does time make a difference? Already we can see that an increase in mash time indicates a difference. We need a lot more numbers to obtain a good average default, however, thanks to your input, we can already say that there is almost definitely a difference and probably a high one. This is extremely important. Why?...

No existing software recognises that time affects efficiency. Nor does any software recognise that gravity affects efficiency. And, we haven't even looked at the mash-out effect.

In other words, all existing software, except some spreadsheets you might find buried here, expect you to brew exactly the same gravity brew for any mash time and get the same result. Or, if you have a ridiculous amount of savvy, ask you to set up a different equipment profile for every gravity brew and mash method you use.

To an experienced brew mathematician, the above is a serious flaw. All the hard calculations have been ignored to date and, they have to be because the most basic data has never been gathered. That is what we are doing here.

What more data do we need in this thread?

This thread is a general thread. It's main aim is to test a general point of view we had and then work out what questions to ask next. 2trout's post above is excellent. It's not critical now but wherever you can, please write as much detail on your mashing methods as possible. Doing this will help us formulate the next questions we need to explore.

Basically, the more you write, the faster we can learn. BUT, we also know that taking measurements is annoying, hard and difficult. Just post what you can do easilly for now.

What you are actually doing here.

Behind the scenes on this site we have been working extremely hard to create a whole new model of brewing education, terminology and software. Very few brewers even realise there is a problem. If you are contributing here, you are making a difference in a bigger way than you are probably currently aware of. Your input here, and our work, will enable as many brewers as possible, of different levels of experience and equipment, to seamlessly come together. (And yes, that even means that a three-vessel, experienced, traditional brewer should love the BIABacus, simple spreadsheet that it is, and the terminology.)

Doing all this has been, and still is, very tricky and time-consuming but we are getting there.

Thanks again for those of you who have jumped in already on this thread with your figures. Hopefully we'll have enough posts here soon to add a time dimension into the BIABacus default auto-efficiency feature.

Cheers,
BB
Last edited by BIABrewer on 06 Dec 2012, 00:30, edited 2 times in total.

Post #24 made 6 years ago
thughes wrote:Notes:
-units are in "American", you'll have to convert to that funny metric system yourself
-pure BIAB (full volume, no sparge)
-gravity reading taken with a refractometer, each sample was drawn into a pipette and pipette cooled with tap water
-refractometer reads in brix, I used this to convert gravity readings

Here you go:

15 minutes: 7.4 brix/1.0282 (mash temp 154F)
30 minutes: 7.8 brix/1.0298 (mash temp 154F)
45 minutes: 8.6 brix/1.0329 (mash temp 154F)
60 minutes: 10.0 brix/1.0384 (mash temp 152F)
75 minutes: 10.5 brix/1.0404 (mash temp 150F)

I then ramped temp up to mashout (168F) over 15 minutes:

90 minutes: 11.2 brix/1.0432 (mash temp 168F)

I let it sit at mashout temp for 15 minutes:

105 minutes: 11.4 brix/1.0440 (mash temp 167F)

Pull bag and squeeze:

pre-boil: 11.5 brix/1.0444 (mash temp N/A)

So, it's only one set of data but it looks like the squeeze is a total waste of time other than getting my pre-boil volume where it needs to be (I only picked up .0004 gravity points). I think I'll just add a tiny bit more starting water and stop wasting my time squeezing!

This is why I no longer squeeze, just let gravity do all the work
Last edited by stux on 09 Dec 2012, 08:47, edited 2 times in total.
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 #25 made 6 years ago
Great to see a post from stux - it's been way too long :peace:.

Just wanted to say hi to Stu but in this thread, I suspect I'll have to post some figures as well so have dug up some very old ones.

All these were taken with a refractometer but have converted them.

20 mins = 1.025
26 mins = 1.032
36 mins = 1.034
46 mins = 1.035
56 mins = 1.037
66 mins = 1.037

Start to rise to mash out temp...

76 mins = 1.039
96 mins = 1.040

No idea why I did a 20 minute mash-out. As I said, these are very old figures :).
Last edited by PistolPatch on 10 Dec 2012, 20:31, edited 2 times in total.
If you have found the above or anything else of value on BIABrewer.info, consider supporting us by getting some BIPs!
    • SVA Brewer With Over 100 Brews From Australia
Post Reply

Return to “Measurement, Mathematics and Records”

Brewers Online

Brewers browsing this forum: No members and 2 guests