How do mashes work?

If i mash at 157*F for an hour and have a complete starch conversion and then let it sit for 3 hours at 149*F, does the 3 additional hours change the wort much?



Also which beer would be more fermentable:

A- mash at 148 for 1 hour
B- mash at 152 for 30 minutes then continue 1 hour at 149

grathan said:

If i mash at 157*F for an hour and have a complete starch conversion and then let it sit for 3 hours at 149*F, does the 3 additional hours change the wort much?



Also which beer would be more fermentable:

A- mash at 148 for 1 hour
B- mash at 152 for 30 minutes then continue 1 hour at 149

Click to expand...

Answers:

No. 157F is a very hot mash, and will result in a wort with low fermentability. Time after that at a lower temp won't help as the enzyme conversions are complete. You should try a good book on this topic, or search for a resource on wort temps as a function of fermentability.

A. Lower mash temps make for a more fermentable wort. Again, read up on alpha vs. beta amylase conversions.

http://braukaiser.com/wiki/index.php/Braukaiser.com

My go-to for technical questions.

Yea you can go up in temp to step up, but can't go down. Say do a 15-20 min mash at 145 and then go up to 157 for the rest of the hour. The goal is not to get all converted at 145 though, otherwise like is said above very watery beer.

Reason you can't go down is because two enzymes are at work that have different heat ranges, and because they are just enzymes, they have no protection from the heat. Once you go past their tolerance they turn into spaghetti (called denaturing) and are useless.

Palmer's website how to brew explains as well. Most people pick one temp where both work, between 150-156ish, and then each one competes with the other and gives you the desired effect. I'm pretty sure it makes the conversion slower though, because both are not operating in each's sweet temp spot.

Thanks guys. Palmer flat out says beta amylase is denatured at 154*-162* and since the braukaiser enzymes page only mentions "hypothetical enzymes" we'll have to accept Palmer's statement as being factual.

So basically I've denatured the beta amylase at 157*f so it makes no difference if I further mash at a lower temperature.

So let's just focus on my second question of which wort would be more fermentable. Palmer states that the Alpha Amylase breaks down the starches into simple straight chains that the Beta Amylase can now convert to maltose. So... If a mash sits for 20 minutes at temperature that favors Alpha Amylase 154*F and it breaks down complex starch chains that the beta amylase normally couldn't handle and then the temperature swing downwards to favor the beta amylase I would think this would create an even more fermentable wort than just sitting at 148*f for the whole time no?

According to Palmer:

"Alpha amylase is instrumental in breaking up large amylopectins into smaller amylopectins and amyloses, creating more ends for beta amylase to work on."

So yea I would say in a given amount of time you probably get quicker conversion that way. I would guess that Alpha is still working even at 148, just slowly, for the well modified malts we use.

Happens all the time in my $hitty mash tun, probably done mashing in 30 minutes after I mash in for 10 minutes at 154 and I end up at about 148 for the other 50:cross:

I have a feeling that is why we homebrewers use more crystal than we really need if we had a proper insulating mash tun.