High gravity BIAB

Post #1 made 3 years ago
One of the frustrations I have found with BIAB was that I was struggling to make high gravity beers. This is only a minor concern as I rarely brew high gravity but from time to time the situation arises and I want to give it a go.

My current situation was that I have a yeast cake for a saison/Brett mix that has already made a saison so I was wanting to brew something big for the yeast cake. I also saw this as an opportunity to try a method for brewing high gravity that I thought would work and wanted to test in reality.

BIABacus already factors in that as the mash gets thicker the efficiency drops off so my hypothesis was that by mashing thinner and extending the boil it would be possible to hit the big numbers.

My plan was to make an imperial porter with a end of boil gravity of 1.100. So by extending the boil to 2 hours and 15 minutes it meant that I mashed in 11kg of grain to about 40L of water. BIABacus calculated a gravity into boil of 1.067 which was achieved. After the boil the gravity was very close to 1.100.

While this makes for a much slower brew day it is the best approach I have tried on brewing high gravity and what I will be using on the future for big beers.

It also left me pondering whether it would be possible to do a kind of partigyle BIAB when using this method.

I use a skyhook system and was measuring some of the wort draining out of the bag at 1.060 so I was wondering whether I could have put that grain aside, reheated some strike water, lowered he bag back in, given it a good stir and remashed to grain to make a small beer? I didn't have the time to do this yesterday but was wondering if anyone has ever tried this. If not I will give it a go next time I brew big.

Post #2 made 3 years ago
Contrarian, A few times I made a 1.080 Stout, I squeezed the *^&*( out of the Bags, and Put it in 2.5 Gallon oh 170F water.
After stirring and Squeezing the &^(%*^%^ out of the bag, I had 1.039Sg to 1.042Sg.

It made a Pretty Good Dark Session Ales, ABV around 3% or so.
Honest Officer, I swear to Drunk, I am Not God.
    • SVA Brewer With Over 100 Brews From United States of America

High gravity BIAB

Post #3 made 3 years ago
What was the initial grain bill and volume of the first mash?

Good to hear that it can be done, it felt like there would a way to do it but was thinking about maybe doing a second mash out so a 15-20 minute steep at 78C. Given I would have already done a mash out there shouldn't be additional conversion, just the rinsing of more sugars out of the mash.

Will definitely try this next time.

Post #4 made 3 years ago
The weight was 15Lbs(us)6.8Kg for 5 Gallon/19L VIB, with a 160 minute Boil to get the 1.080 GAW.

The Second Batch was 2.5 Gallon/12L Dunk Sparge.

You should recover about 40% of the GIB on the First Batch, for the second Half Batch
Honest Officer, I swear to Drunk, I am Not God.
    • SVA Brewer With Over 100 Brews From United States of America

Post #5 made 3 years ago
I tend to parti-gyle whenever I do a high gravity, so it does work no problem.
I don't have the numbers like Joshua, but all looks reasonable to me.

On the odd occasion I add more grain to the second gyle as well. Once I added rye malt to give a different twist, another occasion, roast barley to turn the pale high gravity beer into a normal/low gravity porter.

Your only downside (with only one kettle) is a long brewday. Fortunately for me I still have my original 40L Buffalo urn, that comes into use for those occasions.
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

High gravity BIAB

Post #6 made 3 years ago
My plan is to have a second kettle in the near future which will be a converted 50L keg, hopefully with an electric element so it should be easy to heat that up to whatever temp I am aiming for and just move the bag across.

It's always seemed like a bit of a waste using so much grain for 20L of beer so will be nice to extend it out a bit.

I also like the idea that you could do an IPA for example and then by adding some dark grains make a porter the same day. The possibilities are endless!

Post #7 made 3 years ago
Contrarian wrote:One of the frustrations I have found with BIAB was that I was struggling to make high gravity beers.
Contrarion, this is not a BIAB frustration but a general frustration of brewing high gravity beers. No matter what all-grain brewing method you use, unless you want to add extract, you do need to boil for a lot longer on high gravity brews. It is the only option, full-stop.

And as you've already gathered, there is a lot of 'sugar' left over in the grist. Hopefully, you have read the jeans analogy somewhere here on the site. You will not get a filthy pair of jeans clean with one bucket of water. The first bucket will come out really filthy (high gravity) whilst the second will come out lower gravity but still be quite filthy (sugary).

I tried to do the numbers on this a few years ago and include it in the BIABacus (as current partigyle calculators make several false assumptions) but I think I ran out of time, or nore liekly, room inThe BIABacus to accommodate the calcs. Maybe I'll have another look because...

I like your idea of adding specialty grains to the "second grist" to make a completely different style. I haven't heard of that idea before but it is excellent :peace:.

A few things to note on the partigyle....

1. You won't need to do a second mash as the "second grist" has already been mashed. Specialty grains do not need mashing.
2. With an absence of good partigyle estimates, and given the above, what you could do is slowly add hot liquor until you reach a pre-boil gravity* that will result in your desired OG given the lowest evaporation rate you expect. (The latter ensures that you won't be caught out with a too weak wort. Ask questions if this is not clear.)
3. Let me know of your results if you do try this and I'll see if I can come up with a partigyle calculator that is reality-based.


* This is a good example of where a refractometer can be handy as you will need to take quite a few samples and therefore, won't be relying on just one or two samples.
Last edited by PistolPatch on 27 Jan 2016, 22:26, edited 1 time in total.
If you have found the above or anything else of value on BIABrewer.info, consider supporting us by getting some BIPs!
    • SVA Brewer With Over 100 Brews From Australia

Post #8 made 3 years ago
PP, The PartiGyge system, started with Gravity at 1.111, for the First Batch, That was diluted to the Gravity for the "BEST" product!

The remaining Grains(Starting at 1.111) were sparged to Recover (1.045) for a strong Ale,

and then was Spraged to 1.020 for a "Wee" Ale.

The purpose was to get enough Sweet Liquor, to make and get the "Best Product".

During that Time they Floated things like Raw eggs and cooked eggs to determine Gravity.

The 2nd and 3rd Batches were just "Profit".
Honest Officer, I swear to Drunk, I am Not God.
    • SVA Brewer With Over 100 Brews From United States of America

High gravity BIAB

Post #9 made 3 years ago
It was mally that suggested adding additional grain to the second batch, I was just following that thought along!

Will definitely give this a go next time I brew. I am thinking that it would be possible to do an IPA and a mild on the same day by adding some chocolate malt and maybe some abbey to the second rinse.

I get that the second rinse doesn't need to be mashed so there are 2 ways you could go. One is to start with an estimate of the water required and boil to a target gravity, the other would be to 'sparge' by adding water until you have a desired pre boil gravity.

My hunch is that it would be easier to estimate the water required and boil down with my set up than the other way around.

I am also assuming that mash out temp water would be better at rinsing the grain as it would make the sugar less viscous but would it be possible to rinse the grain with tap water and some kind of spray nozzle?

My jumping off point will be to aim for a 20L cube of IPA at around 1.065-70 and a 15L cube of mild at around 1.030.

I use a refractometer so can take a few measurements along the way so I will record and post back here. Am keen to try it this weekend now but will need to make sure that I have enough spare cubes and it fits in with the family!

Post #10 made 3 years ago
I had planned on doing something similar a while back adding base and specialty grains into the bag for the second beer. I never had the time on the planned day so it never happened. I am definitely going keep an eye on this to see how things progress.
Some people are like slinkies. Not good for much, but bring a smile to your face when pushed down the stairs.

    • SVA Brewer With Over 20 Brews From Canada
Post Reply

Return to “BIABrewer Old Hands”

Brewers Online

Brewers browsing this forum: No members and 6 guests