Double mash

[Josh Hughes]

I’m planning to brew a 5 gallon batch, I usually do 3.

Think I’m going to double mash Saturday so I can do a 5 gallon batch. My biab kettle doesn’t hold the grain for 5 gallons without spilling the good stuff.

I figured I would use the salts for the full mash and put 6 gallons of water in the kettle. Mash half the grain. Pull the bag drain and then put the other half of the grain in for a second mash. I’ll sparge with a gallon of water rinsing the second bag.

Can you foresee any concerns?

 

[J A]

I wouldn't do that...your mash thickness would be very weak and you risk not keeping enzymes in contact with starches. Mash as you normally would with half the liquor and the first bag and drain off the runnings into your boil kettle. Repeat with the second bag. If it was me, I'd do a dunk sparge/rinse and use the same sparge water for both bags.

I have to split mashes when I do a 20 gallon batch and it makes for a long brew day. I have to go all the way through the full mash and fly-sparge process twice.

 

[Josh Hughes]

I mash and brew in the same kettle. So in my situation you would mash as normal empty the runnings then mash the rest of the grain and water? Then add all running back to kettle for the boil?

 

[Josh Hughes]

I have a small electric BIAB, a giga wort I haven’t used in a few years since due to its ability to brew an all grain batch above 2 gallons was a mess. I may just mash 2-3 pounds of grain in there and the rest as normal on my propane kettle. I can even bring it to a boil for a decoction if I’m paying attention.

This would save me an hour.

 

[The Brew Mentor]

Do you have 2- 6.5 gallon brew buckets?
You could make up a ZapPap lauter tun pretty quickly.
Man does this go WAYYYYY back!
I still have my original one from 17 years ago.
Cheers
Brian

 

[Josh Hughes]

Do you have 2- 6.5 gallon brew buckets?
You could make up a ZapPap lauter tun pretty quickly.
Man does this go WAYYYYY back!
I still have my original one from 17 years ago.
Cheers
Brian

No

 

[J A]

I have a small electric BIAB, a giga wort I haven’t used in a few years since due to its ability to brew an all grain batch above 2 gallons was a mess. I may just mash 2-3 pounds of grain in there and the rest as normal on my propane kettle. I can even bring it to a boil for a decoction if I’m paying attention.

This would save me an hour.

That could work... I acquired a really good 10-gallon infusion tun that I've been using for 5-gallon batches. If I need to run a big batch in the future, I plan to run as much as possible in my 15 gallon HERMS tun and fill up the infusion tun to make up the difference. That allows running mashes simultaneously and saves a lot of time - for me at least 2 hours.

 

[J A]

I mash and brew in the same kettle. So in my situation you would mash as normal empty the runnings then mash the rest of the grain and water? Then add all running back to kettle for the boil?

I realized that it might be possible, depending on your volumes that you could run the first mash in half your liquor or as much of it as would give a decent mash thickness and then use the same wort for mash liquor on the second half. That way your active enzymes are using the same grain to liquid ratio and should be pretty efficient. You'd have a partial volume of strong wort and then you can use your remaining mash water to sparge/rinse both bags. It requires a separate sparge vessel but would save handling and liquid transfer overall.

 

[HighVoltageMan!]

I’m planning to brew a 5 gallon batch, I usually do 3.

Think I’m going to double mash Saturday so I can do a 5 gallon batch. My biab kettle doesn’t hold the grain for 5 gallons without spilling the good stuff.

I figured I would use the salts for the full mash and put 6 gallons of water in the kettle. Mash half the grain. Pull the bag drain and then put the other half of the grain in for a second mash. I’ll sparge with a gallon of water rinsing the second bag.

Can you foresee any concerns?

This is completely doable. The dilution of enzymes is not a concern. This method can also be used for high gravity beers.

I see no reason your first plan won’t work. Some people will mash one batch and then collect, add new grain and add back in the wort from the first batch. It’s been known to work well. Your idea is a variation this method.

 

[Donoroto]

I’m planning to brew a 5 gallon batch, I usually do 3.

Think I’m going to double mash Saturday so I can do a 5 gallon batch. My biab kettle doesn’t hold the grain for 5 gallons without spilling the good stuff.

I figured I would use the salts for the full mash and put 6 gallons of water in the kettle. Mash half the grain. Pull the bag drain and then put the other half of the grain in for a second mash. I’ll sparge with a gallon of water rinsing the second bag.

Can you foresee any concerns?

Sounds like a solid plan.

Your second mash will be slightly less efficient because the wort already has some sugars in it, but no cause for worry.

Only alternative would be two identical mashes with 3 gallons each. Sounds like more work though.