30 min mash conversion

Did an experimant this weekend while brewing my all gain stout. I did an iodine test every 10 while mashing to see when conversion took place....30 min is what I got with the maris otter that I used. I use the BIAB method. Just wondered if anybody else has timed their conversion time, and if the thickness of the mash was a contributing factor? It was only around an 8lb grain bill for 5 gal. and mashed at 158?

This is not surprising....modern malts are so well modified that conversion can happen very quickly. Higher temps will also speed up the process.

I have been thinking about going to a shorter mash to get some more body in my beers. I've measured complete conversion at 10 minutes, before, so I think a 30 minute mash isn't out of line. I know many professional breweries have very short mash times.

I checked at 10 and 20, but really wasn't satisfied that it converted, but the 30 min was a definite...when I went to clean up as it started to boil, the equipment was good and sticky, so I know there were sugars present....also my fingers stuck together! LOL

Anybody recall the BYO/BBR experiment a year or so ago? They found that although you can get indications from a starch test in 20-30 min., a longer mash actually made a better beer. My own experience is that I far prefer beers made with a 60-90 min. mash.

http://www.basicbrewing.com/index.php?page=basic-brewing-radio-2011

well I guess we'll see, since this is a recipe I've made several times.

I think perhaps with the thin wort, the higher temps that I mashed at the the style of beer I'm brewing, that the short mash time would work. With other styles, such as belgians, I definitely think the longer mash is beneficial.
I normally do mash for 60 min, but I like to try different techniques, because to me, saying something won't work, just because the book written 20 years ago said it wouldn't isn't convincing to me. ok..truth be known, I'm a stubborn ass! LOL

I'm the same way, which is why I tried a short mash a few times. I'm back to 60-90 min. based on the results of my trials.

If conversion is complete at 30 min but a higher quality wort is produced at 60 then I see two things that happen. Either additional enzymatic activity occurs taht affects the sugar/starch or other flavor compounds, proteins, are extracted after 30 min. I think the latter is quite significant but much more difficult to quantify compared to conversion.

Enymatic breakdown continues well past 30 min.

Denny said:

Enymatic breakdown continues well past 30 min.

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Indeed. Which is why I'm guessing (not an expert) that the only result of a long mash is a more fermentable wort. There's no enzyme in wort that's chaining small sugars back together. If you're going for a more full bodied dixtrinous wort, a short mash could be desireable.

I don't think a longer mash= a more fermentable wort, isn't it the mash temp? I mean if you mash at 158 for an hour versus 30 minutes won't you get the same body(FG) in the end product. And (I too am no expert) if you mash at 158 until a negative starch test, you pretty much have your fermentability and final gravity set in place, you can't then mash for longer while the temperature in the mash drops and expect to get a lower final gravity. True?

somedudefromguam said:

I don't think a longer mash= a more fermentable wort, isn't it the mash temp? I mean if you mash at 158 for an hour versus 30 minutes won't you get the same body(FG) in the end product. And (I too am no expert) if you mash at 158 until a negative starch test, you pretty much have your fermentability and final gravity set in place, you can't then mash for longer while the temperature in the mash drops and expect to get a lower final gravity. True?

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Not necessarily. It's important to have an idea of how the two saccharification enzymes work together to make wort sugars out of starch in the grain.

Some beta amylase will still be active at higher temperatures, and add to that the fact that alpha amylase is still working and you'll get more and more fermentable wort.

Let's say you have complete conversion of the starch to sugar in 30 minutes. That means you probably have a lot of long chain sugars, some of which are shorter (more fermentable than others). Neither enzyme can make a sugar longer, but both can cut up the existing long chain sugars FURTHER into smaller and smaller sugars. Therefore, longer mash= more fermentable wort.

Temperature definitely is a major factor, as it tips the balance between one enzyme and the other, but time is another important factor.

I know this beer was chugging away about two hours after I pitched the yeast.