Eager to try out BIAB for a big Imperial Stout - new for me

[thehaze]

Hi,

I have been using a Grainfather ( 220V version - european ) for alomost 4 years now and it's been a treat: a little over 100 batches, never issues with pump, recirculation, heating element, temperatures, controller, etc. So from that point of view, this particular Grainfather unit I own, it's a great and reliable piece of quipment. I try push the limits of it, every batch - I've been able to package 24.5 ( 6.5 gallons ) liters of beer. I use Speidel HDPE fermenters - the 30 liters/8 gallons version.

Now, I wish to be able to brew a 10-12% Imperial... anything really, and 20-25 liters of it. Kind of hard with a Grainfather, due to its size. I've been doing som double mash batches, and they turned out great, but mashing twice or more, is a pain. So I'm thinking of getting a 55 liters/15 gallons stainless steel pot with a BIAB bag and do a big mash in there, for an Imperial Stout. The boiling will be undertaken in the Grainfather still, but seeing that I can fit 34 liters in it ( 9 gallons ), I hope to transfer around 7 gallons to the fermenter.

I can find a 15 gallons pot for the equivalent of 40 US dollars ( single wall - no reinforced bottom, but I will not be boiling the wort in it ) and a bag to fit it for 9-10 US dollars. Would this work? After the mash is done, I transfer the wort to my kettle and boil.

Any input is welcome. Thank you.

 

[ChiknNutz]

I don't have a lot to offer aside from saying that seems like it should work. I am also about to embark on a large Imperial Stout very similar to what you propose, so have an interest in this as well. I recently picked up a nice used 15G kettle (BrewBuilt with the thick bottom) and a new BIAB bag for this very purpose, since my 10G kettle would not support such a grain bill for a full volume mash.

 

[WNKbrew]

It will fit in a 15g pot but IMHO without sparging your efficiency will suffer. It will be 14g no sparge

 

[thehaze]

It will fit in a 15g pot but IMHO without sparging your efficiency will suffer. It will be 14g no sparge

Thank you for the reply. I don't wish to sparge, as this would defeat the purpose of mashing this way - I don't want to diluate and thin out first runnings. I also don't care about efficiency, because I'm not trying to use less malts to achieve a specific OG / ABV, on the contrary, I am using more malts and it is intended.

So it would work well? I would mash in the Grainfather and in the pot simultaneously, so my question is: will the cheaper SS pot work well to mash some extra grains?

 

[RM-MN]

I can find a 15 gallons pot for the equivalent of 40 US dollars ( single wall - no reinforced bottom, but I will not be boiling the wort in it ) and a bag to fit it for 9-10 US dollars. Would this work? After the mash is done, I transfer the wort to my kettle and boil.

That thin walled pot would work fine for mashing and boiling in. When you do a big beer you need to use more grain and that usually causes efficiency loss so you have to take that into account and add more grain. The other options include milling the grain finer and/or sparging. With BIAB you can mill the grain very fine without problems provided you do not recirculate. Recirculation will cause the fine particles to clog up the pores in the bag.

A suggestion for this batch is to do your no-sparge big beer and put that wort into your Grainfather for the boil, then pour some water over the bag of grains that you have set back into the thin walled pot as a sparge and collect those runnings as a "small beer". You will have left a lot of the sugars in that bag of grains and it would be shameful to just throw it all away. This would be a smaller batch, perhaps 10 to 15 liters. This is known as partigyle and is not uncommon.

 

[thehaze]

That thin walled pot would work fine for mashing and boiling in. When you do a big beer you need to use more grain and that usually causes efficiency loss so you have to take that into account and add more grain. The other options include milling the grain finer and/or sparging. With BIAB you can mill the grain very fine without problems provided you do not recirculate. Recirculation will cause the fine particles to clog up the pores in the bag.

A suggestion for this batch is to do your no-sparge big beer and put that wort into your Grainfather for the boil, then pour some water over the bag of grains that you have set back into the thin walled pot as a sparge and collect those runnings as a "small beer". You will have left a lot of the sugars in that bag of grains and it would be shameful to just throw it all away. This would be a smaller batch, perhaps 10 to 15 liters. This is known as partigyle and is not uncommon.

Thank you for your reply.

I've actually thought about partigyle every time I did a double mash, and never got to it - was either too tired, or didn't really have the disposition, the energy to do it, so I skipped it. But I might just do it with this batch. Could turn out to be a small, chuggable brown/Mild ale of sorts. I will not recirculate, but only let the malts steep for 60-90 minutes, so I will mill finer.

 

[Jayjay1976]

To figure out the max amount of grain you can mash, google biab volume calc. You can trade some water to give more space for grain, but as others have said, your efficiency will suffer real bad. It's not about saving money or being wasteful, it means you won't hit your target gravity and it isn't something you can easily predict. Sparging will help a bit, but in general it's not a good way to brew.

If your goal is a nice, high-gravity stout, replace some of the base malt in your recipe with LME/DME to make up the difference between what you can reasonably mash and your target gravity. I attempted an 1.126 bourbon county stout clone and ended up with only 1.110 or so. Wasn't prepared for that and didn't have any extract so I couldn't fix it. On subsequent brews I've used extra light LME without issues. Sounds counterintuitive in a dark beer but you're only replacing base malt. Amber would be okay too and adds flavor, but watch the SRM.

I'd bet that some smaller breweries use extract to boost wort gravity too, unless really big beers are their focus. Think of it as extending your capabilities without adding equipment.