Can you explain this mash schedule?

[pwnshop]

Hi guys,

Im going to be brewing a hefeweizen (my first one) tonight and i was wondering about the mash schedule in this wiki article:

http://braukaiser.com/wiki/index.php?title=Weissbier_Hell

it details a "maltose" rest at 145 degrees followed by a "dextrinization rest" at 160. I have done a little googling of those terms and I wasnt really able to find any clarification.
Typically when i see a step mash schedule the first rest is really low like 122 degrees or something like that.
Ultimately I would like to know if this is a good mash schedule for a hefe and what the two steps will achieve. Would like the end result to be full bodied.

If anyone has any suggestions for a better mash schedule maybe you can suggest it here? I will be doing water infusions as my mash tun doesnt have a heat source and I really dont feel like doing a decoction (unless it turns out it is hands down the best for a hefe?). I batch sparge.

Thanks guys!

 

[Oginme]

There are two main enzymes which produce fermentable sugars from the starches contained within your typical malts. The first is beta-amylase and the second is alpha-amylase. Each of these has a specific temperature range within which they are the most efficient.

The first rest cited as a 'maltose' rest, is at 145F which is near the peak of activity for the beta-amylase enzyme. This enzyme bites off groups of two sugar molecules (maltose) from the ends of the starch chains. This enzyme is most active from about 131F to 149F. It has activity beyond 149F, but its efficiency diminishes beyond the 149F as the enzyme denatures faster at these temperatures.

The second rest is at the high peak for alpha amylase. This enzyme randomly cleaves larger chains of starch molecules into smaller chains. It is more effective at the higher temperatures, though there is some activity at the 145F temperature rest. Since it works on longer chain starches, it will reduce them to smaller chains of sugar, but is generally ineffective at creating fermentable sugars, instead leaving more dextrins which are sugar chains of 3+ sugar molecules long.

You can design a multiple infusion mash system to get you these temperature rests, if that is your desire.

 

[bigdongsr94]

https://missionarybrewer.files.wordpress.com/2012/02/enzyme_activity_one_hour_mash.jpg

 

[pwnshop]

Awesome information.

Thanks man, that was a really helpful explanation! In the context of a hefewiezen does this mash schedule make sense? The only place I have seen this schedule is on this wiki article!

 

[Oginme]

Kai's instructions usually tend to be along traditional German brewing techniques. It certainly looks to fit that bill and should work just fine.

Since he states that this can be brewed with decoction or infusion mashing, I would suspect that there is not a lot of melanoidin development in the finished beer flavor. Since I fit my brewing to a busy schedule, I would simplify it to a single infusion, probably at about 148F or 150F to balance towards a little more fermentability and call it good. If I had plenty of time, it would be fun to do this as a decoction. Either should work fine.

 

[pwnshop]

Kai's instructions usually tend to be along traditional German brewing techniques. It certainly looks to fit that bill and should work just fine.

Since he states that this can be brewed with decoction or infusion mashing, I would suspect that there is not a lot of melanoidin development in the finished beer flavor. Since I fit my brewing to a busy schedule, I would simplify it to a single infusion, probably at about 148F or 150F to balance towards a little more fermentability and call it good. If I had plenty of time, it would be fun to do this as a decoction. Either should work fine.

thanks for taking the time to explain. cheers!

 

[Cyclman]

Kai is definitely a German beer jedi, I am sure if he posted a recipe, it'll be great.

 

[pwnshop]

OK an update:

I did this mash schedule last night and it went pretty well. My only issue was that apparently the beersmith calculation for the infusion to hit 160 was off? I ended up at 157 as opposed to 160.. I boiled some additional water and dumped it in and stirred but that only raised it to just above 158 (i have never been able to recover well from undershooting mash temps).

Im wondering if the second step sitting at 157 - 158 as opposed to 160 will have any kind of negative impact? conversion was completed and I hit all my numbers right on, that was the only hiccup.

 

[Oginme]

Don't worry, it will be beer! I've had the same issue with trying step mashes and decoctions. The problem, IMHE, is that there is generally no real good way to account for a drop of 2 to 3 degrees in temperature in the main mash kettle due to the opening, stirring and removing (in the case of the decoction mashes) some of the wort. The program works with the information it is given and cannot fully model my real life process in these particular circumstances. Mind that it is spot on with single infusion mashes. To compensate, I've changed my boiling temperature for decoctions to about 206F (vs. actual which is 211F at my altitude) and it seems to get much closer to reality. BeerSmith then calculated that I needed to take out more of the mash for decoction to raise the temperature to reach target.

With multiple infusions (and honestly I've only done a few), I heat up a bit more water a few degrees higher than calculated and add most of the water, stir until the temperature is settled and then add more if needed. When I do this, I calculate my mash profile with a fairly generous sparge which I can then subtract any extra water I've used in the infusion steps.