Complete starch coversion?

[jstrausss]

I see a lot of receipts that say Mash until starch coversion is complete. Is there an easy way to know when that would be?

[O2 Mash]

Originally posted by jstrausss
I see a lot of receipts that say Mash until starch coversion is complete. Is there an easy way to know when that would be?

Yes, there is a very easy way. Buy a small (1oz) bottle of iodine. When you take a drop of your mash and add a drop of iodine to it, it will turn black or purple if there is still starch. If your conversion is complete, the iodine will stay the same color.

[jstrausss]

O - Man thats awsome - Thanks so much

[brewmonkey]

Make sure that if you use the iodine test, you take the sample away from the mash tun. Even a small amount of ioding into the mash will spell trouble.

[Caffinehog]

Don't worry about it. Have a homebrew. If you don't know if it's converted, give it more time. All-grain is about patience. Can you wait an hour to convert the grain? Can you add a half hour if you aren't confident it's done? Many people make delicous all-grain brews without ever checking to see if conversion is complete. Think the brewers of old-time checked? Heck, they didn't even have thermometers! (Hence decoction mashes...)

[MrMethane]

Originally posted by Caffinehog
Don't worry about it. Have a homebrew. If you don't know if it's converted, give it more time. All-grain is about patience. Can you wait an hour to convert the grain? Can you add a half hour if you aren't confident it's done? I don't do all grain yet so forgive me if this is a stupid question, but can't mashing for too long cause the wort to pick up excess tannins from the husks? Or does that happen from mashing with water thats too hot?

[brewmonkey]

Originally posted by Caffinehog
Don't worry about it. Have a homebrew. If you don't know if it's converted, give it more time. All-grain is about patience. Can you wait an hour to convert the grain? Can you add a half hour if you aren't confident it's done? Many people make delicous all-grain brews without ever checking to see if conversion is complete. Think the brewers of old-time checked? Heck, they didn't even have thermometers! (Hence decoction mashes...)

With the modification of modern malts this is the truth. I rarely ever checked for conversion as I don't keep iodophor around and I always hit gravity.

[O2 Mash]

Originally posted by MrMethane
I don't do all grain yet so forgive me if this is a stupid question, but can't mashing for too long cause the wort to pick up excess tannins from the husks? Or does that happen from mashing with water thats too hot?

Yes, I believe you are correct on BOTH accounts, but I believe this question might be better answered by Brewmonkey or Stodbrew.....O2

[brewmonkey]

Originally posted by O2 Mash
Yes, I believe you are correct on BOTH accounts, but I believe this question might be better answered by Brewmonkey or Stodbrew.....O2

Yes, both are possible. To long and to hot will cause problems. The modification of todays malts (expressed as DP on most malts) is such that most have converted in 15-30 minutes.


Going in to hot or running your sparge to hot will cause tannins to leach giving off an astringent flavor.

[toneyc]

I am finding it hit or miss on making my gravities. For example, I made a Blonde Ale on Friday. The recipe called for 9 pounds of two row and I tossed in an extra pound. Mashed for 60 minutes right at 152*F, and *still* missed the 9 pound gravity target by .005. The week before, I made a Mild Ale and overshot the gravity by .003. Should I be adjusting my temps, or mashing longer, or what?

Edit: Should I stir the mash during the 60 minutes, or just leave it alone?

:eek:
Toney.

[brewmonkey]

Are you adjusting your recipes based upon the malt specs for the maly you are using? Well they are all in the ballpark they will be different. The extract of American Klages or Harrington is certainly going to be different then that of a British Golden Promise. Over the course of a 9lb bill though it would be enough to throw a recipe off by 1-1.5P.

The mash should be throughly mixed but once that occurs it can be left alone. I don't think mashing longer will help extract either.

Some factors in extract potential:

Grind of the grist. Were both batches the same base malt? Where they milled to the same specs (on the same mill)?

When you started to lauter/sparge did you first bring the mash up to mash out temps to decrease wort viscosity? Doing so will allow for a better run off and add in the gravity issues.

Was the pH of the mash optimum? This is probably one of the biggest killers I run into when mashing. The pH should be in the 5.1-5.3 range and above 5.5 you can run into some serious efficiency problems.

If the pH is the problem it can be fixed through the addition of acid, I prefer to adjust my strike water for this but it can be done in the tun as well. Food grade phosphoric acid (85%) can be added, in a home brew tun I would think using an eye dropper drop by drop until pH is achieved will suffice. Citric or Lactic acid will also work.

The other method to drop pH is either incorporate an acid rest at 95F for 15 minutes before heading to saccharification rest or you can add a dose of acidulated malt. About a lb should do the trick to most grain bills. You treat it like any other 2 row but it will help keep mash pH in check. Weyermanns makes an acid malt under the name Sauer Malz.

The last thing would be just plain luck. I am usually within my target range and when I am not as long as it is not more then .75P either side (.003) of the target I don't worry to much as it might just be the way the planets aligned this morning.

[Fast_Eddy]

Yeah - I'll kick in with brewmonkey here especially about the pH. I've been super steady on hitting my gravities since I've become very particular about mash and sparge pH over the last 1.5 years or so. The beers, IMO, wind up with a cleaner, more well defined taste too.


I guess one other pH adjuster(used in hard water with darker ales) that wasn't mentioned and can be used for a drop of a few .X's of pH is gypsum. Added into the kettle it reacts with the phosphates in darker malts and precipitates out in solution HCO3, thereby lower mash pH. Also adds sulfate which contributes a little to having a crisper hop bitterness.

A tip I picked up recently for adding gypsum, CaCl, CaCO3, etc - is to dissolve it in a cup of (pH adjusted) water before adding to the mash. You get much more even distribution.

[toneyc]

OK, PH and sparge water temp may both have a role to play in my situation. The Mild is very dark, almost as dark as the Stouts I've made, but the Blonde was not dark. And my water usually measures about 8 ph. Next time, I'll adjust the ph. And my sparge water may have been a few degrees low, too. Thanks, guys!

:)
Toney.