Mash times

[VikeMan]

What size breweries are we talking about?

Batch sizes were between 15 gallons and 15 barrels.

 

[oakbarn]

If the solids give a positive starch response with iodine, that means the solids (grits) still contain starch. If this is the case, then conversion is not complete.

Brew on

I agree with only checking the liquid. Even after a 90 min mash, a grain will turn black with iodine. I used to test but no longer do as it can be misleading. I simply use Temperature and Time (and I do use a modified HERMS, for the Mash. I cut one Mash short using the Iodine Test and I obviously misread the results. Most of the time, we mash for 90 minutes.

 

[Vale71]

Batch sizes were between 15 gallons and 15 barrels.

Ok so probably just lazy then...

 

[Vale71]

I agree with only checking the liquid. Even after a 90 min mash, a grain will turn black with iodine.

I'm not hundred percent sure but I think iodine will react strongly with non-soluble, non convertible polysaccharides that will stay behind in the spent grains so that basically a iodine test with solid particles will always show positive no matter how long you wait.

 

[RM-MN]

The grain particles will only turn blue/black if there is starch left which then implies incomplete conversion. I have tested this with my own milled grains and will get no color change with the iodine. To achieve this the particles of grain must be small, much smaller than can be used in a conventional mash tun without a filter bag.

 

[Vale71]

Those very small particles are just made of fiber (husk material) which is why they don't react. Endosperm fragments will always react with iodine which does not imply incomplete conversion.

 

[RM-MN]

So check the solids or liquid or both?

Do you want to check for complete conversion (not easily achieved for most people) or do you want to check to see if you have unconverted starch in the wort? Your original question was, "How do I tell when the conversion of the starch are complete?" That doesn't matter in the context of making beer from a recipe. You want sufficient conversion, enough to get the OG of the recipe which was likely written with about 70% brewhouse efficiency. That doesn't require complete conversion, it requires that you get enough so that when you extract the sugars from the grain by draining the mash tun (probably followed by a sparge to get some more sugars) you hit the desired OG.

 

[RM-MN]

Those very small particles are just made of fiber (husk material) which is why they don't react. Endosperm fragments will always react with iodine which does not imply incomplete conversion.

Nope. If that were the case I would always get a color change from the iodine being applied to the grist. Since I don't, that can't be the case.

 

[tommy24a]

Do you want to check for complete conversion (not easily achieved for most people) or do you want to check to see if you have unconverted starch in the wort? Your original question was, "How do I tell when the conversion of the starch are complete?" That doesn't matter in the context of making beer from a recipe. You want sufficient conversion, enough to get the OG of the recipe which was likely written with about 70% brewhouse efficiency. That doesn't require complete conversion, it requires that you get enough so that when you extract the sugars from the grain by draining the mash tun (probably followed by a sparge to get some more sugars) you hit the desired OG.

You are correct, my original question was how do I tell if I have let it mash enough time. My recipe calls for 75mins mash time but my equipment process guide says 30 to 45 mins is sufficient due to the efficiency of the MT.

 

[RM-MN]

You are correct, my original question was how do I tell if I have let it mash enough time. My recipe calls for 75mins mash time but my equipment process guide says 30 to 45 mins is sufficient due to the efficiency of the MT.

You won't really know until you have done a few batches and checked how close your OG comes to the recipe's OG. Most people achieve this with a "standard" 60 minute mash. If your grains are milled more coarsely a 75 to 90 minute mash may be needed. If the grains are milled really fine, less time is fine. Do not go less than 30 minutes as the flavor takes longer to extract than does conversion with finely milled grains.

 

[tommy24a]

You won't really know until you have done a few batches and checked how close your OG comes to the recipe's OG. Most people achieve this with a "standard" 60 minute mash. If your grains are milled more coarsely a 75 to 90 minute mash may be needed. If the grains are milled really fine, less time is fine. Do not go less than 30 minutes as the flavor takes longer to extract than does conversion with finely milled grains.

Thanks for your input!
☺

 

[jdudek]

You won't really know until you have done a few batches and checked how close your OG comes to the recipe's OG

your OG will also depend on grain absorption and boil off rate. If you're interested in your conversion efficiency, you need to test it against your pre-boil gravity.

 

[oakbarn]

When I see all the "faith" some have in the "science" you can go crazy with this hobby:

https://www.cdrfoodlab.com/foods-beverages-analysis/analysis-starch-beer/
And an article for understanding the process:

https://www.braukaiser.com/wiki/index.php/Starch_Conversion
My advice: Follow the Recipe.

 

[tommy24a]

When I see all the "faith" some have in the "science" you can go crazy with this hobby:

https://www.cdrfoodlab.com/foods-beverages-analysis/analysis-starch-beer/

Nice price..$6k lol