Taking SG, TG in Grain-In Mash

[KBFreeRange]

We run grain in our mash all the way through the process (cooking-distillation) and have a question about taking specific gravity and terminal gravity readings with this type of mash. Do the mash solids in the liquid distort the readings when using a typical SG hydrometer? If so, is there a reliable way to remove the solids so an accurate reading can be taken?

[Brian]

Although not particularly scientific, you could use a paper towel as a filter and get most of the solids out.....its seems to me like it is more about the relative difference from start to finish in a mash. Probably more betterer to just perform your tests the same way all the time....you will get a sense of your conversion....there are some easy to use pH test strips...check for starch conversion with iodine...you can get over the top about technique....but I would say that consistent is good....make notes....keep a record and you will start to see trends worth chasing and some not so much...

B

[nuffield]

You won't get an accurate reading with a hydrometer. I use a refractometer to get a brix reading and convert it to SG. This is the easiest and very quick.

[JohninWV]

I take Brix readings with an electronic meter like this:

http://www.novatech-usa.com/Products/Atago-Brix-Refractometers/3810-PAL-1

As discussed in another email, iodine readings aren't real trustworthy with grain mashes. I wonder if I'm getting false readings on my Brix due to doing these readings with the grain in the test sample?

[coop]

I take Brix readings with an electronic meter like this:

http://www.novatech-usa.com/Products/Atago-Brix-Refractometers/3810-PAL-1

As discussed in another email, iodine readings aren't real trustworthy with grain mashes. I wonder if I'm getting false readings on my Brix due to doing these readings with the grain in the test sample?

I use a refractometer also. I use it at the end of my mash run after conversion with malted barley. Mine reads brix on one side of the scale and possible alcohol on the other side. This lets me know if I have a complete conversion of the starches and just how much starch i am really getting cooked out. It only takes a drop of liquid to work and you can always get a clean drop. Coop

[JohnD]

I may be wrong here but these refractometers give an indication of simple sugars in the mash, but have no way of quantifying starch left in the mash. You know that you are getting hydrolysis, but have no way of knowing whether you are hydrolyzing completely. I'd say if you want to remove solids invest in a small centrifuge.

[coop]

[quote name='JohnD' date='14 May 2010 - 06:53 PM' timestamp='1273884788' post='5556']

I may be wrong here but these refractometers give an indication of simple sugars in the mash, but have no way of quantifying starch left in the mash. You know that you are getting hydrolysis, but have no way of knowing whether you are hydrolyzing completely. I'd say if you want to remove solids invest in a small centrifuge.

If a person is mashing up any thing, grain,fruits whatever they should already know what amounts of starch or sugars are available from that product. The TTB does. That is why you have to record all purchases and uses and report it every month. That way the TTB can see if you are claiming the right amount of alcohol produced from those products. There are charts that show the maximum amount of sugars available in what ever you are using. Say you are using three different kinds of grain. Each one has a value. You take the total of all three and divide it by three, that gives you a % amount that you should be shooting for. So if that value adds up to say 7.5 % and after converting all available starches to sugar and you use a refractometer that shows both brix and value of alcohol, your reading should be close to the 7.5% available. If you get a reading of say 4% available then you did not get all the starches either converted or cooked out of the mash. when I start to get about .5% to .75% lower than I should be getting it is usually that my grind of the grains is not small enough to get the starch cooked out of the grain in the allotted cooking time. I either have to cook longer or grind a little smaller. I know that it is that my grinder needs to be set a little smaller then it goes right back up to where it should be. The brix reading on the left does away with any particulates that would effect a specific gravity reading making the process much easier. Coop

[JohninWV]

Where are these charts, coop?

What refractometer are you using?

[coop]

Where are these charts, coop?

What refractometer are you using?

I am an old man, 62 now and memory not at good as 3 years ago when I used it. I will try to find it and when I get back to the shop on Tuesday will send you info on refractometer. I think it only cost me around $40.00. Coop

[delaware_phoenix]

Novatech has a number of different handheld refractometers for under $100. Look for one that covers the ºBrix range you want and to what accuracy. The Atago brand has both digital and analog version, many with automatic temperature correction.

http://www.novatech-usa.com/Products/Vee-Gee-Handheld-Refractometers

http://www.novatech-usa.com/Products/Atago-Brix-Refractometers

[coop]

Novatech has a number of different handheld refractometers for under $100. Look for one that covers the ºBrix range you want and to what accuracy. The Atago brand has both digital and analog version, many with automatic temperature correction.

http://www.novatech-usa.com/Products/Vee-Gee-Handheld-Refractometers

http://www.novatech-usa.com/Products/Atago-Brix-Refractometers

OK have not been able to find my chart but will keep looking. As for the refractometer is is a model ATC 513. I purchased it from G.W.Kent, their item 1729 for $39.00

[JohnD]

OK have not been able to find my chart but will keep looking. As for the refractometer is is a model ATC 513. I purchased it from G.W.Kent, their item 1729 for $39.00

Thanks Coop, I've been wondering how folks use those to get good numbers. Looking for one of those charts now. I'll post it if I find one.

Best,

John