Using Megapot as BIAB

[nwbrewing32]

Hey everyone,

How well do you think a Megapot 1.2 (8) Gallon kettle would work for BIAB? I would do full volume mashes (BIAB as well) so it'd only be filled to maybe 5.5 gallons.

Is this this too much headspace? Would it hold temp for an hour?

 

[MaxStout]

There are people who successfully brew 5 gallon BIAB batches in 8 gallon kettles, so it CAN be done. That said, it's a tight fit. Go to one of the online calculators and see how much volume you need. You must account for boiloff, grain absorption, trub, etc.

Do you already have the kettle? If not, give serious thought to a 10 or even 15 gallon BK.

 

[LLBeanJ]

8 gallons is going to be tight for full volume, but doable some of the time. Bigger beers (i.e., bigger grain bills) and longer than 60 minute boils are going to push the envelope and require a sparge step. If you already have the pot, go for it, but just be aware it won't always hold all the water and grain needed for a full volume mash. If you are contemplating buying one, go for a 15 gallon kettle instead and thank me later. FWIW, I started out with an 8 gallon pot and used it for nearly 3 years, but was mostly doing 3-5 gallon brews. I had to do a sparge most of the time when doing 5 gallon recipes due to exceeding the available volume. I recently upgraded to a 15 gallon Megapot 1.2 and have been doing 6 gallon recipes with no issues. I still do a small sparge to coax a few more gravity points from the mash, but could easily do full volume if I wanted to.

 

[ZebulonBrewer]

This is a pretty great calculator that I've used once or twice. Works well.

http://pricelessbrewing.github.io/BiabCalc/

Plug it all in and if the numbers make sense, have at it.

 

[Gavin C]

I have a 10 gallon Megapot. It would hold 11gallons. I use it for 5.5 gallon batches. With 90 minute boils I start with 7.5 gallons. Mashing bigger beers would be doable in an 8 gal Megapot (probably 9 galon capacity) by incorporating a sparge to reach your desired preboil.

Head space will certainly not be a concern.

For the beer I like (ie not big DIPA RIS etc) my 10 g Megapot is more than adequate for my needs.

 

[nwbrewing32]

Sorry I should've mentioned I'm doing three gallon batches so it will have 3 gallons headspace roughly

 

[nwbrewing32]

And I'm mostly concerned about holding temp

 

[Gavin C]

If doing 3 gallon batches 8g would be plenty.

You will have a 9 gallon capacity approx in the Megapot. Probably about 5 gallons of volume after adding grain. even a massive beer with a long boil you would not go much over 6 gallons of volume.

Sounds like the right job.

Just a heads up if you are looking at the pot with the thermometer and valve from NB. I wouldn't bother with the thermometer as the one they supply is not great and you can get the valve cheaper elsewhere along with any other fittings you might need.

I do like having the valve.

This is my 10g pot in action.

Insulation helps keep temps stable.

A typical full volume mash for 5.5 gallon batch

 

[nwbrewing32]

But will mine hold temperature for an hour without adding heat?

 

[wilserbrewer]

An 8 gallon pot may fit in your oven, on a low setting this works great to hold mash temps.

 

[LLBeanJ]

But will mine hold temperature for an hour without adding heat?

Probably not unless you can mash in the oven as suggested by wilserbrewer or you insulate it real well like Gavin's pictures show. I add heat every 15-20 minutes. I tried insulating and found it to be more of a hassle than just firing up the burner a few times for a minute or three during the mash. Also, I have no empirical evidence to back this up, but I like to believe that the stirring that takes place while heating helps with conversion.

 

[wilserbrewer]

Holding heat will likely be a bit tricky with only 3 gallon batches.

With larger batches, even modest insulation works well enough, but with such a small mass of grain you may need to add some heat. Also, IMO don't let losing a few degrees deter you....just make adjustments and mash higher anticipating the temp loss.

 

[Gavin C]

Also based on some recent posts by @RM-MN with fine milling, much if not all of the conversion will occur in the first 10 minutes or so. That is not to say the mash is complete but that the most important phase of it relating to temperature control may be the most important and be over pretty quickly.

Mashing in the oven is a great idea. I did it once on one of my first BIAB brews. I have a hold warm setting so can set the oven to 145F if needed. Check the oven first as the setting may be hotter than it tells you.

The dimensions of the pots are on the NB website. Measure the oven and see if it fits.

A little heat loss is no major drama however. Insulation is easy and cheap to setup. Comes on and off as needed in seconds. Alternatively a winter coat or a blanket work too.

Makeshift insulation

 

[wobdee]

I've got the 8 gal mega pot and brew 3 gal BIAB batches and it works great. Plenty of room and little chance of boil over. I double wrap reflectix insulation around the kettle and lose about 1° in about 45 min during mashing.