Water mineral profile adjustment for high proportional boil-off rates (small batches)

[Iggles]

Hi everyone,

My question is whether it is recommended to adjust the water mineral profile for boiling off proportionally large volumes during brew day, for example when brewing small batches? And if so, which minerals would you adjust?

As an example, if you are targeting a 1-gallon fermenter volume (including trub) and lose 0.7 gallon from boiling off, this would mean the initial 150 ppm SO4 becomes 255 ppm. In a 5-gallon setup, it changes only to 171 ppm. I am mostly thinking about Na, Cl and SO4 as the situation with other minerals seems to be more complicated (Mg originating mostly from the grains, HCO3 and Ca being partially lost to precipitation).

Any feedback is much appreciated!

 

[day_trippr]

Interesting question. I would love to hear @mabrungard's take on this and how it might apply to Bru'n Water.

Cheers!

 

[tracer bullet]

Sparging or not sparging becomes a question.

You'll of course have alkalinity and pH up front for mashing, then the various concentrations for the final product. 2 things to consider if it wasn't obvious (probably was obvious given the question being asked).

There's also the "don't boil off nearly half your water" aspect. You might want to lower the heat a bit!

 

[VikeMan]

There's also the "don't boil off nearly half your water" aspect. You might want to lower the heat a bit!

OP is starting with 1.7 gallons and losing 0.7 gallons. I would challenge anyone to lose less in 60 minutes and still have a rolling boil with an open kettle.

For a given kettle and constant boil "vigor," boiloff volume is more a constant than it is a percentage of starting volume. I don't know why some brewing software even offers a boiloff percentage parameter as an option, in regard to calculating pre to post boil volume.

Interesting question. I would love to hear @mabrungard's take on this and how it might apply to Bru'n Water.

Here's something he wrote about the issue.

Boil-Off Calculation: Does It Matter? | Bru'n Water

 

[AlexKay]

I lose nearly a gallon for my 1.25-gallon batches. I lose only ~0.4 gallon for my 0.5-gallon batches, but those I boil in an asparagus steamer (tall and thin pot.)

Here's a thread where I asked something similar (and Martin replied):
Less Salt for Long Boil?

Basically, make sure your calcium is >50 ppm for the mash, but for the flavor-relevant ions (sodium, sulfate, chloride) work with the final concentrations in the cases that they're very different from the initial.

 

[day_trippr]

Here's something he wrote about the issue.

Kinda saw that coming. Bru'n Water does not try to calculate the wort minerals & pH in the finished wort - ie what goes in the fermentors.
But it could, I think.

This is from Bru'n Water 5.5 "Help":

"Water Volumes: Enter the water volumes to be used in the brewing and production in the BLUE cells at the top of the Water Additions area. Enter the total volume of water that will be added to the mash tun as the Mash Water Volume. Enter the total volume of water that will be added for mash out and sparging as the Sparge Water Volume. Enter the total finished volume of the batch as the Total Batch Volume. The Total Batch Volume is only used to estimate the beer color (SRM) on the Grain Bill Input sheet. Note that the Total Batch Volume will be less than the mash plus sparge volume due to grain adsorption, evaporation, etc. "

I read that a few times and I'm still not sure what Martin wants me to enter for "Total Batch Volume" on the Water Adjustment sheet. I've been using Bru'n Water for years and always enter the "end of boil" volume for "Total Batch Volume" - before I subtract losses due to kettle hops and lautering losses. But reading the above makes me think he's actually looking for the "total pre-boil volume", which makes me sad if true.

"Got Guidance"? Maybe I can coax Martin @mabrungard to swing by

Cheers!

 

[Iggles]

Thanks for your answers and informative links, which generally seem to confirm my suspicions

The 1.7 -> 1.0 gal example was just an example of my very first brewing experiences. My boil-off rate is currently still high though because I need 2 brew pots for my 3-gallon batches (low-BTU kitchen stove is my only option at the moment).

I think I will keep with my current approach, which is to (1) choose a suitable water profile in Brewfather, (2) proportionally adjust for boil-off loss (allowing further tweaking specifically for Ca and HCO3) and (3) then do the salt addition calculations. I figure if I'm going to be micromanaging this, I would rather do it somewhat right.

 

[tracer bullet]

Thoughts, cause it's a forum, hah

I don't buy the "no boil" idea but I'd bet that a roiling boil isn't needed. Try a batch at a good simmer. Or whatever you want to call it. Have it steaming, have it moving, but don't boil so much off. Don't use 2 pots, just use 1. It's a small batch, give it a shot, see if you can taste any difference.

Or, set your water for mashing to be the right amount to have 1.0 gallons run off. Minerals to taste for final results but also with mash pH in mind. Sparge with 0.7 gallons RO water. Now you have 1.7 gallons thinned out. Boil down to 1.0 to be back to where you started and planned.

Clearly not as easy as it sounds but...

 

[BeerAndTele]

I recall asking this same question some time ago, because I brew small batches too.

In an average batch for me, I have ~3.5 gallons pre-boil and 2.6 after the boil. So in these cases, I'm boiling off ~26% ... and therefore my concentration of ions are up 35% from the values after the mash (which my water calculator gives me). In your case (1.7g down to 1.0), you're boiling off 41% and therefore your concentrations are up ~70%.

My thinking - and I could be wrong - is that most calculators don't worry about post-boil concentrations because an average brewer boiling off a gallon to land on a 5 gallon post-boil volume is only boiling off 17% and therefore ion concentrations are only up ~20% ... less for larger batches ... so the difference isn't appreciable. But your 70% change could be more noticeable.

As a result, my approach FWIW is to take a less-is-more approach ... 1. Because I generally brew lighter styles that benefit from softer water, and 2. because I figure I'm seeing a greater increase in concentrations as a result of the boil than a guy brewing a 5 gallon batch.

At the same time, I'll admit that it's entirely possible that I'm over-thinking it and I'd never detect the higher concentrations anyway.

Cheers.

 

[day_trippr]

Well, if anything, I'd be most likely to over-think this.
In fact, who the heck brought this up to begin with?

 

[ScrewyBrewer]

Hi everyone,

My question is whether it is recommended to adjust the water mineral profile for boiling off proportionally large volumes during brew day, for example when brewing small batches? And if so, which minerals would you adjust?

As an example, if you are targeting a 1-gallon fermenter volume (including trub) and lose 0.7 gallon from boiling off, this would mean the initial 150 ppm SO4 becomes 255 ppm. In a 5-gallon setup, it changes only to 171 ppm. I am mostly thinking about Na, Cl and SO4 as the situation with other minerals seems to be more complicated (Mg originating mostly from the grains, HCO3 and Ca being partially lost to precipitation).

Any feedback is much appreciated!

I calculate the total strike and sparge water volumes needed to produce enough wort to fill a keg up to my target volume, then treat that total strike water volume to match a water profile. Of course, before knowing just how to treat the total strike water volume, you also must know which grains and their weight will be used in the recipe.

 

[mabrungard]

I read that a few times and I'm still not sure what Martin wants me to enter for "Total Batch Volume" on the Water Adjustment sheet.

As the comment text said, its only used for beer color estimating. Don't read too much into that volume.

Regarding the OP's original question; Yes, excessive boil off can be a serious issue for small batch brewers. You definitely don't want to produce that excessive boil off since it overconcentrates the wort and any constituents in it.

While you may need to perform a long boil duration to convert the DMS precursor (SMM) to DMS, it does not require an open or vigorous boil to be completely effective at that chemical process. The kettle can be completely covered and the heat turned down so that the wort is only lightly moving within the kettle. However, ejecting all that DMS from the wort is necessary at the end of the boil and that is accomplished by uncovering the kettle and boosting the heat until the wort is moving somewhat briskly (not volcanic) so that all of the wort circulates across that wort surface where it can eject the DMS into the air. That open boiling period only needs to last a half hour or so in order to get good DMS removal. This covered and then uncovered kettle procedure is how any brewer can keep their wort from incurring excessive volume loss. You want to limit the volume loss to about 5 to 10 % of the total starting wort volume. I aim for around 8% myself.

 

[Iggles]

As the comment text said, its only used for beer color estimating. Don't read too much into that volume.

Regarding the OP's original question; Yes, excessive boil off can be a serious issue for small batch brewers. You definitely don't want to produce that excessive boil off since it overconcentrates the wort and any constituents in it.

While you may need to perform a long boil duration to convert the DMS precursor (SMM) to DMS, it does not require an open or vigorous boil to be completely effective at that chemical process. The kettle can be completely covered and the heat turned down so that the wort is only lightly moving within the kettle. However, ejecting all that DMS from the wort is necessary at the end of the boil and that is accomplished by uncovering the kettle and boosting the heat until the wort is moving somewhat briskly (not volcanic) so that all of the wort circulates across that wort surface where it can eject the DMS into the air. That open boiling period only needs to last a half hour or so in order to get good DMS removal. This covered and then uncovered kettle procedure is how any brewer can keep their wort from incurring excessive volume loss. You want to limit the volume loss to about 5 to 10 % of the total starting wort volume. I aim for around 8% myself.

Thanks for the feedback, Martin: I will follow your advice to minimize boil-off during the first half of the boil. I do always make sure that grain bill and hop additions are adjusted to final postboil volume, but I will rethink my current very convoluted boil setup that's taking away some of the fun of brew day.