Question about rests

I'm looking at the SNPA clone on the recipe section here and I was just wondering about the different rests.

Saccharification Rest: 153 60 Min
Mash-out Rest: 168 15 Min
Sparge: 170 60 Min

The saccharification rest makes sense to me and seems to be the typical single infusion type mash. What does the mash out rest do?

Since I am going to be doing my first AG batch this weekend, what do I have to gain by hitting that the mash out rest and can I skip it, and what will I expect to be different?

Thanks!

If you are batch sparging, you can safely skip it. If you are fly sparging, it has a two-fold purpose: reduce the viscosity of the mash to aid in lautering, and to raise the temperature of the mash so the enzymes are denatured/deactivated to halt conversion.

I'll be batch sparging. I figure that's a good first step. Thanks!

I'd agree with FlyGuy about the theoretical purpose of a mash out, but there is one other thing to consider. Raising the temperature of the mash also makes the sugars generated by the mash more soluble. If the first batch of sparge water is hot enough to raise the temperature of the grain up to 170, the sugars will be dissolved more easily and you should achieve better efficiency.

-a.

So if you were to do a batch sparge and at the end of the 60 minutes do you put in X amount of water at near boil temps to bring the mash/water up to 168 then after 15 minutes drain and put in the 170* water to sparge?

FSR402 said:

So if you were to do a batch sparge and at the end of the 60 minutes do you put in X amount of water at near boil temps to bring the mash/water up to 168 then after 15 minutes drain and put in the 170* water to sparge?

Click to expand...

Exactly. Depending on your batch size, temps and cooler size, sometimes it's hard to add enough water for the mashout without either overflowing your cooler or messing up your batch volumes...I'll sometimes pull an all-liquid decoction to make sure the temp hit 168 or so.

Also, I generally go a little high on the second batch sparge water temp (maybe 175) since the grain bed will cool below 170 as you drain the first batch.