Reiterated Mashing

[Brewmasher]

For some reason, it took me this long to discover reiterated mashing. My question, is it beneficial to use the liquor from the first mash as the strike water for the second mash?

My plan is to mash and sparge the first time to half of my kettle volume. My kettle (grainfather) is 8 gallons, so I mash half my grain bill, then fly sparge until I reach 4 gallons. Then drain the (now mash tun), dump the spent grain, and mash the second half of the grain bill with fresh strike water, and sparge for another 4 gallons. I will then add my first runnings to the kettle, and boil as usual.

To me, this would be the most efficient way, unless somehow the enzymes of the first runnings provides a more efficient second mash. It doesn’t make sense to me to forego sparging on the first half of grains, and saturate the second grain hulls with sugar laden liquor, that is, unless it makes a difference.

Any thoughts?

 

[Zemillard90]

Wow, I can't believe I'm just learning about this now, thanks for posting!

I did find another thread about this saying neither mash was sparged.

https://www.homebrewtalk.com/threads/my-reiterated-mash-experience.659513/
Hope this helps! Cheers!

 

[Brewmasher]

I can see when brewing in a bag where sparging would be impossible or difficult. Wouldn’t it be more efficient to sparge and use fresh water for the second mash if your system will allow it?

 

[Zemillard90]

As you described above, you are draining the mash tun into the boil kettle after the first mash and essentially repeating the process? Sorry if I am misunderstanding your proposal.
But, if that is the case I think you just end up with 8 gallons of wort with half the gravity you want. If you wanted to make a 1.080 (preboil) wort using your process, I think you just end up with 8 gallons of 1.040 (for example, or whatever you get from the first mash) wort. You are essential not using reiterated mashing, but doing a single mash twice.
When you use the wort from the first mash as strike water for the second you are already starting with 1.040 (in this case) wort and whatever sugars are extracted in the second mash will add to that for your boil.
I am sure some efficiency may be lost. Perhaps a sparge after the second mash could be beneficial, but I do not know much about this process. Thanks for bringing it up, I finally have a way to do a barleywine!!

 

[Brewmasher]

Not really. For a 20# total grain bill for 8 gallons pre boil, that would be 2- 10# mashes yielding 4 gallons of wort ea. At 70% efficiency, that would be a pre- boil gravity of 1.065

I’m going to try it tomorrow. I’ll post my results.

 

[ike8228]

But wouldn’t there be some level of saturation by using the first mash as a strike. I’m still learning all grain my self but I would think if the water is saturated (unable to dissolve more sugars into the volume, think sugar at the bottom of a glass of lemonade), you wouldn’t be extracting the sugars from the second batch as well. Perhaps if sparging more than normal. Again I’m still learning and it may not be a factor, but it’s the first thing that popped in my mind.

 

[Brewmasher]

I’m thinking not sparging the first run is going to waste sugars soaked in the husk. Then more sugars will be absorbed into the second mash, but at least those will be somewhat sparged out.

 

[doug293cz]

But wouldn’t there be some level of saturation by using the first mash as a strike. I’m still learning all grain my self but I would think if the water is saturated (unable to dissolve more sugars into the volume, think sugar at the bottom of a glass of lemonade), you wouldn’t be extracting the sugars from the second batch as well. Perhaps if sparging more than normal. Again I’m still learning and it may not be a factor, but it’s the first thing that popped in my mind.

At mash temp you can dissolve enough sugar to get your SG over 1.300. There is no practical way to saturate the wort with sugar by mashing.

Brew on

 

[doug293cz]

I’m thinking not sparging the first run is going to waste sugars soaked in the husk. Then more sugars will be absorbed into the second mash, but at least those will be somewhat sparged out.

The only way to get really high gravity pre-boil wort is by cutting down on your lauter efficiency. If that bothers you, then sparge, but don't combine the initial runnings with the sparge runnings. Ferment the sparged wort separately. This is what a partygyle is all about.

Reiterated mashing is useful when trying for very high pre-boil gravity, but you can't get all of the grain and water needed in your mash tun.

For example, to get 6.5 gal of 1.100 pre-boil wort, you would have to mash 33.2 lb of grain in 10.66 gal of water, giving a mash volume of 13.3 gal. If you have a 10 gal MLT, this is a no go. By mashing half the grain, and then mashing the second half of the grain in the first runnings of the first mash, you can reduce your mash volume to fit your MLT.

Brew on

 

[Brewmasher]

Brewed yesterday using reiterated mash. The new brew shop in town crushed my grains way too fine. I had a hopelessly stuck lauter/ sparge. 20 years of brewing, I have never had a grain bed stuck this bad, even using adjuncts. Still splitting up a 20# mash was easier to manage. I was able to rescue a 60% efficiency. At least I had a worst case scenario practice run.

 

[Zemillard90]

How did you end up doing it? Sparge or no sparge? And did your gravity come out ok?

 

[Brewmasher]

The stuck grain bed really reduced the session to a practice run. When I lifted the grain basket out of the Grainfather to drain/ sparge, the wort only dropped less than a 1/4" in a half hour! The only way I could collect the wort was to stir the bottom of the basket with my grain paddle to produce a path for the wort to drain

I used 3 gallons of strike water for 10# of grain. After draining the basket, I meant to sparge with 2 gallons to get me around a 4 gallon yield. Again it was hopelessly stuck. Basically a hybrid batch sparge, I added the water, and stirred so it could drain. I got 4 gallons of 1.065 wort, only about 60% efficiency.

I added 3.5 gallons to the grain to sparge my second strike water. I got a 1.012 running off the second sparge.

Second mash went about the same. I yielded a total of 8 gallons of 1.065 wort, about 60 % efficiency. Not what I was hoping for, but I'm sure the compacted grain bed had a terrible lauter, if any at all. I'm sure it would have been much worse, and a total pain in the ass if I mashed the entire 20# grain bill all at once. Next time I will remember to condition my grain before crushing, and make sure it is not crushed too fine. I have never had a stuck grain bed that bad in 20 years of brewing. Even using adjuncts like oats and wheat.

The good news is the Kriek yeast is chomping away at the wort like a beast! I added some sugar to boost the gravity to 1.073. Plan is to ferment at the highest temp naturally possible. This brew is to see what kind of flavors I get off of Kviek.