Once I hit estimated preboil OG is mash over?

[Nubiwan]

Simple BIAB question. I usually mash for an hour, but if I take a gravity at 30 minutes, and my pre-boil OG is established, is there any harm in starting the boil?

Is preboil OG simply a function of the mash? Or does something else happen during the mash, that I need to concern mysefl with?

I took out a sample at 30 minutes today. I am going to have a look and see what SG it gives me.

 

[Bobby_M]

Gravity is a measure of dissolved sugar density so it's definitely not unconverted starch but you do not know if it's Glucose, Maltose, Maltotrios, or Dextrines. You MAY have a less fermentable mixture the moment you hit your desired OG. However, my guess is that if you hit it in 30 minutes, you probably were going for a moderate to low fermentability anyway with the higher mash temp.

 

[VikeMan]

Gravity is a measure of dissolved sugar density so it's definitely not unconverted starch but you do not know if it's Glucose, Maltose, Maltotrios, or Dextrines.

We generally treat gravity as a measure of dissolved sugar, but it's actually a measure of density (relative to water), which is affected by any dissolved solids. So soluble starches (if unconverted) would still contribute to wort's gravity.

Here's 2 oz of Dingemans Pilsner Malt, ground finely, added to 16 oz room temp distilled H20, shaken for about 30 seconds, strained with a kitchen strainer, and measured:

 

[Nubiwan]

Gravity is a measure of dissolved sugar density so it's definitely not unconverted starch but you do not know if it's Glucose, Maltose, Maltotrios, or Dextrines. You MAY have a less fermentable mixture the moment you hit your desired OG. However, my guess is that if you hit it in 30 minutes, you probably were going for a moderate to low fermentability anyway with the higher mash temp.

I took the sample at 30 to compare with a sample at 60, and it was different. Lower as you'd expect. Think they were 1.040 and 1.050. Significant difference. Of course, it was difficul;t rendering accurate temperatures to read with my hydrometer. Next time, I think I will do it with greater control.

 

[day_trippr]

Ugh. Hopefully nobody's gonna see that hydro pic and run out to create a "White NEIPA"...

Cheers!

 

[grampamark]

Ugh. Hopefully nobody's gonna see that hydro pic and run out to create a "White NEIPA"...

Cheers!

Heading over to the recipe forum in 3...2...

 

[day_trippr]

lol!

 

[VikeMan]

Ugh. Hopefully nobody's gonna see that hydro pic and run out to create a "White NEIPA"...

Why not? Plus, there's no need to measure FG!

 

[kevin58]

There is a Youtube channel called the homebrew challenge where the host is brewing 99 BJCP beer styles in 99 weeks so of course he is looking to make his brew days as efficient as possible. Calling his mash finished once he has reached his desired post mash gravity is one of the things he does to achieve that. So yes, once you have reached the gravity you expect to achieve move on to the next step.

 

[Bobby_M]

We generally treat gravity as a measure of dissolved sugar, but it's actually a measure of density (relative to water), which is affected by any dissolved solids. So soluble starches (if unconverted) would still contribute to wort's gravity.

Here's 2 oz of Dingemans Pilsner Malt, ground finely, added to 16 oz room temp distilled H20, shaken for about 30 seconds, strained with a kitchen strainer, and measured:

Thanks for that. I honestly didn't know there was that much soluble starch available at room temp. I figured you'd need a small amount of gelatinization to get there.

 

[RM-MN]

Simple BIAB question. I usually mash for an hour, but if I take a gravity at 30 minutes, and my pre-boil OG is established, is there any harm in starting the boil?

Is preboil OG simply a function of the mash? Or does something else happen during the mash, that I need to concern mysefl with?

I took out a sample at 30 minutes today. I am going to have a look and see what SG it gives me.

If your grain is milled to near flour you may find the the OG is stable in less than half an hour and that the final gravity that your beer may reach does not change but it still takes time to extract the flavors so don't cut the mash too short. I don't recommend less than half an hour mash because of that.

 

[Vale71]

Thanks for that. I honestly didn't know there was that much soluble starch available at room temp. I figured you'd need a small amount of gelatinization to get there.

There's sugars already available in malt even without further conversion too.

 

[Vale71]

I'm surprised nobody has mentioned it yet. If you want to ensure full conversion which is paramount to the quality of your beer you need to be performing a iodine test each and every time to confirm conversion. Any other method is unreliable and not to be trusted.
If on the other hand you want to do "short and shoddy" and don't care about quality because you're trying to beat some silly record or something then all bets are off and you could even refrain from measuring OG or anything else for that matter...

 

[bracconiere]

We generally treat gravity as a measure of dissolved sugar, but it's actually a measure of density (relative to water), which is affected by any dissolved solids. So soluble starches (if unconverted) would still contribute to wort's gravity.

Here's 2 oz of Dingemans Pilsner Malt, ground finely, added to 16 oz room temp distilled H20, shaken for about 30 seconds, strained with a kitchen strainer, and measured:

i've tried floating my hydro in gel'd gravy, and given enough time it sinks to 1.000....i think the stuf has to be in solution to actually effect the hydro.....

 

[VikeMan]

There's sugars already available in malt even without further conversion too.

For a base malt, about 1% or less.

 

[VikeMan]

i've tried floating my hydro in gel'd gravy, and given enough time it sinks to 1.000....

I'm not going to ask. So why... Nope, not going to ask.

i think the stuf has to be in solution to actually effect the hydro.....

Soluble starches are, well, soluble.

 

[bracconiere]

Soluble starches are, well, soluble.

not really, it's my understanding their as soluble as a sponge in water....the starch when heated springs open and traps water but isn't actually dissolved in water?

 

[VikeMan]

i think the stuf has to be in solution to actually effect the hydro.....

not really, it's my understanding their as soluble as a sponge in water....

What do you think caused the hydrometer to float so high? (It was the same an hour later, when I dumped it.)

 

[bracconiere]

I'm not going to ask. So why... Nope, not going to ask.

in my early days of trying to use raw barley....i got paste, and had to leave the hydro in it for a day or two....

 

[bracconiere]

What do you think caused the hydrometer to float so high? (It was the same an hour later, when I dumped it.)

it's malted barley....? at room temp the starch wouldn't gel and be soluble....

 

[Vale71]

For a base malt, about 1% or less.

It can actually be as high as 10%.

https://books.google.it/books?id=bH...oECAoQAQ#v=onepage&q=malt composition&f=false
You've then got 8 to 11% protein of which 35 to 42% is soluble (according to the Kolbach Zahl) and then you've got soluble pentosans and lipids and minerals, most of which will go into solution without further enzymatic action.

EDIT: you have to scroll down to table 4.2, sorry.

 

[VikeMan]

EDIT: you have to scroll down to table 4.2, sorry.

There's no table 4.2 visible in the preview when I click the link and scroll. Can you take a screen shot?

 

[bracconiere]

i just double checked the gravy thing and boiled some wheat flour, diluted with cool water to room temp....got 1.000? not sure....there was an episode of Good Eats where he had the visual aid of spring loaded things poping open.....think that's what i'm going by....

 

[Vale71]

There's no table 4.2 visible in the preview when I click the link and scroll. Can you take a screen shot?

Just scroll down to page 65? I can display the table with no issue.

 

[VikeMan]

Just scroll down to page 65? I can display the table with no issue.

"Pages 64 to 65 are not shown in this preview."

 

[Nubiwan]

I'm surprised nobody has mentioned it yet. If you want to ensure full conversion which is paramount to the quality of your beer you need to be performing a iodine test each and every time to confirm conversion. Any other method is unreliable and not to be trusted.
If on the other hand you want to do "short and shoddy" and don't care about quality because you're trying to beat some silly record or something then all bets are off and you could even refrain from measuring OG or anything else for that matter...

Got a wife and 4 kids. My time spent brewing, even though I love it, is short and shoddy and, I value breathing.

Seriously though, I am able to make my kids lunches, throw some laundry in the washer and dryer, and empty my dishwasher. All at times when I'm either waiting for water to heat up, 1 hour mash, and even my boil. Not like I want to sit and watch beer boil.

So my question is more one of efficiency vs redundancy. If I can achieve in half hour what is supposed to take an hour, the I am all for it.

 

[Nubiwan]

There is a Youtube channel called the homebrew challenge where the host is brewing 99 BJCP beer styles in 99 weeks so of course he is looking to make his brew days as efficient as possible. Calling his mash finished once he has reached his desired post mash gravity is one of the things he does to achieve that. So yes, once you have reached the gravity you expect to achieve move on to the next step.

Doesn't really answer my question though, or does it! I've read people increase their grain bill in order to improve efficiency, but that's not really what they are doing. They are just getting to their post mash Gravity with more grain. So my question remains, what else happens - can happen - once estimated post mash Gravity has been attained?

 

[RM-MN]

Doesn't really answer my question though, or does it! I've read people increase their grain bill in order to improve efficiency, but that's not really what they are doing. They are just getting to their post mash Gravity with more grain. So my question remains, what else happens - can happen - once estimated post mash Gravity has been attained?

Increasing the grain bill may improve time efficiency but not conversion efficiency. Usually the larger the grain bill the lower the conversion efficiency.

What I have found is that it takes more time to extract the flavors from the grain than for conversion. Mill your grain to near flour and you get conversion extremely quickly and if you then start heating that wort towards a boil immediately you will get an alcoholic "beer" that has the alcohol content but is pretty flavorless. You might want to try it once but I will bet you won't want to try it twice.

 

[VikeMan]

Usually the larger the grain bill the lower the conversion efficiency.

Generally speaking ("all other things being equal"), mash efficiency is lower with larger grain bills, due to total water being smaller in relation to the grain bill size. But why would conversion efficiency be lower, assuming same mash thickness?