Water To Grain Ratio

[Darren]

stiff mash means dough balls and tightly compacted grain/channelling!
To release the sugars well, a stiff mash would need to be stirred.
Just my experiences.
Stiff mashes are more likely to stick too!

 

[Tim]

You're right, they're not directly related. There is a correlation though, as high sugar concentration does inhibit enzyme action.

No it doesnt. Reaction kinetics specific to each enzyme are independent of sugar concentration. If anything, starch conversion will be faster in a thicker mash as there is more substrate available to the enzyme active site. I dont think the products of the conversion (sugars) are going to result in competitive inhibtion of the enzyme (which would result in a slower mash).

Anyone working in Biotech. or Mol. Bio. (ie Darren) care to do the experiment and publish the resultant lineweaver-burke plot??

 

[Ross]

stiff mash means dough balls and tightly compacted grain/channelling!
To release the sugars well, a stiff mash would need to be stirred.
Just my experiences.
Stiff mashes are more likely to stick too!

[post="58810"][/post]​

I don't see how the thickness of the initial mash has any bearing on the batch sparge... All mashes should be stirred well anyway, so really don't see any issue...

 

[Wortgames]

I thought mashes shouldn't be stirred?!

 

[homebrewworld.com]

Well, i would stir my mash so i can be sure i have even temp throughout the mash. No need to stir constantly, but you dont want scorching either if direct heating in a steel pot !
And it smells nice too if you have a whiff while stiring.

Oh.. I dont stir when brewing ( thanks to RIMS ! )
But i stir every opportunity i get, when not brewing !

 

[Kai]

You're right, they're not directly related. There is a correlation though, as high sugar concentration does inhibit enzyme action.

No it doesnt. Reaction kinetics specific to each enzyme are independent of sugar concentration. If anything, starch conversion will be faster in a thicker mash as there is more substrate available to the enzyme active site. I dont think the products of the conversion (sugars) are going to result in competitive inhibtion of the enzyme (which would result in a slower mash).

Anyone working in Biotech. or Mol. Bio. (ie Darren) care to do the experiment and publish the resultant lineweaver-burke plot??

[post="58812"][/post]​

I have read that sugars do act as competitive inhibitors in the mash, but my memory of bio classes is faulty as I spent most of them asleep.

 

[warrenlw63]

FWIW I usually mash (single temp) at a ratio of 3lt per kg. Seems to work quite well with good conversion etc.

Started doing this on the advice of Wes Smith. Can't remember the proper reasoning behind this other than the fact that Wes told me that a lot of commercial/micro operations do this. Care to elaborate Wes?

That said I used to mash at 2lt per kg with no real problems either. Main improvement with the thinner mash seems to be that it's far easier to dough in and my HLT is on the smallish side (at the moment). This allows me to use less sparge water. Plus a 38lt mash tun has the capacity for the higher L/G ratio.

Thinner mash also seems to give a more uniform temp across the grain bed and seems to reduce hot spots in the mash. Mind you this is purely empirical. I've got nothing to really substantiate this other than my experiences YMMV.

Warren -

 

[sluggerdog]

OK I am mashing again at the moment and it has been in there for 1 hour at 65C (water ratio 2:1) I have just done an iodine test and it seems I still have not converted the starches so I was wondering does anyone have any tips on how to improve this conversion?

- Do I need to mash for longer then 1 hour?
- Higher Temp?

- I am using Calcium Sulfate already

Thank You

 

[Jovial_Monk]

The iodine turned black or blue or red??

I suggest adding in some more hot water, stir and let it stand again

Jovial Monk

 

[sluggerdog]

Iodine turned black.


I have just added some a few litres of 80C water, will let it sit for 10 mins then I will re-iodine test.

 

[sluggerdog]

The 80C and 10 mins seemed to work, iodine test didn't turn black now, cheers JM!

 

[sosman]

OK I am mashing again at the moment and it has been in there for 1 hour at 65C (water ratio 2:1) I have just done an iodine test and it seems I still have not converted the starches so I was wondering does anyone have any tips on how to improve this conversion?

- Do I need to mash for longer then 1 hour?
- Higher Temp?

- I am using Calcium Sulfate already

[post="60139"][/post]​

Slugger - it is not super critical - 1 hour at 65 C should do the trick. Check your thermometer, if it is more than a few degrees out of whack that could help explain it.

Other things to check:

- iodine test: make sure you are getting a clear sample. I have some pics at http://brewiki.org/IodineTest but please read the notes from all the folk who actually know something about this.

- Grain bill. You need sufficient enzymes to convert the mash.

- Thermometer, already mentioned. Check that it is close.

 

[Jovial_Monk]

Hmm iodine turning black is not a good sign. You only used wort, not grains, in the iodine test?

JM

 

[Darren]

You're right, they're not directly related. There is a correlation though, as high sugar concentration does inhibit enzyme action.

No it doesnt. Reaction kinetics specific to each enzyme are independent of sugar concentration. If anything, starch conversion will be faster in a thicker mash as there is more substrate available to the enzyme active site. I dont think the products of the conversion (sugars) are going to result in competitive inhibtion of the enzyme (which would result in a slower mash).

Anyone working in Biotech. or Mol. Bio. (ie Darren) care to do the experiment and publish the resultant lineweaver-burke plot??

[post="58812"][/post]​

Nope not me! I have thought about it but there are so many variables (ie heat losses) and my lack of available time.
It would be an intersting experiment though I agree

 

[sluggerdog]

Thanks Jayse yeah I get ya... I think I will still try a thinner mash next time and see how things go.

Will try a 2.5:1kg

[post="58785"][/post]​

My second full mash with smaller boil is complete. I did use the 2.5:1 instead of the 2:1 and tried a few other things differently.

Last time I got 50% efficiency

This time I got 62%, I'm happy with these results, you learn as you go.

Thanks for all the input.

ADAM
SD :beer: