Pre sparge gravity

Hi!

I don't know if this is the right place for this topic, so feel free to move my post if it's in the wrong forum.

I'm using a braumeister and one thing that i really miss (maybe there already is this feature but i haven't found it) is pre sparge gravity, both expected and measured.

Thanks!
/Bernt

What exactly is pre-sparge gravity?  The SG of the mash in the MLT before lautering?  I used to measure that to confirm conversion was complete (stable readings indicates it maxed out), but don't recall seeing it in BSmith.  I'd think your water volume would have to be precise for an Estimate to be accurate. 

bhe said:

I'm using a braumeister and one thing that i really miss (maybe there already is this feature but i haven't found it) is pre sparge gravity, both expected and measured.

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By "miss" do you mean it's in another program?

I'm assuming you mean your conversion gravity? As ML said, predicting it depends on a very precise liquor to grist ratio. It's also very incidental.

However, you can use a chart far more easily on brew day. You don't have to be as precise. One caveat is that in some cases, the gravity can exceed the target. It depends on the malt batch.

Attached is the conversion chart from Kai Troester. Kai has done a lot more experiments than I ever will and his data is highly reliable.

Hi and thanks for the answers.

While brewing i take SG Readings several times. I'm using a braumeister and often have a pretty high efficiency, which is depending on how much malt i use. If i use a lot of malt the efficiency goes down a little since it's quite packed in the malt pipe. So your table does only work for a normally packed maltpipe.

In order to hit my wanted pre boil gravity, i try to adjust with more or less sparge water.

Since i entered the volume of water and weight of grain in BS it should be possible for the software to predict a pre-sparge SG, right? There is an expected pre-boil gravity, so why not a pre-sparge?

I understand that people who use the infusion technique wouldn't have use of a pre sparge SG value, but as a BM user i would appreciate such a value since i can easily take SG readings during the complete brew.

Thanks!

bhe said:

If i use a lot of malt the efficiency goes down a little since it's quite packed in the malt pipe. So your table does only work for a normally packed maltpipe.

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I think you don't understand the chart, then. This isn't a mash efficiency chart, it's conversion, based on pale malt. With accurate strike water volumes, you should be able to see first wort gravities at or close to those numbers. Besides incomplete conversion, the only reasons for a lower number is poor milling or grains that have a lower than nominal yield (~80%).

In order to hit my wanted pre boil gravity, i try to adjust with more or less sparge water.

Click to expand...

You shouldn't have to, if you're using the word sparge correctly (water washed through the grain to rinse sugar). If proper conversion is achieved and the sparge is effective, the preboil gravity is spot on. The Braumeister hoists the grain above the kettle, so it's pretty much a BIAB method, where water can be poured through, but doesn't pick up as much sugar as other methods.

If you're simply adding water to dilute the kettle, that's not sparging in an effective sense. Sorry to sound so pedantic, but brewing terms are vague, but have contextual meaning and I want to be clear.

Since i entered the volume of water and weight of grain in BS it should be possible for the software to predict a pre-sparge SG, right? There is an expected pre-boil gravity, so why not a pre-sparge?

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It does, but it's embedded. It'd follow the chart I showed you. Recording the number is important to see how different grists vary. However, it's a needless calculation that creates a culture of pseudo accuracy and intimidates newer brewers. There's already enough of that going on with IBUs and pH.

Sorry for mixing dilute and sparge (even though i would dilute during the sparge), english is not my native language since i'm from sweden.

Yes I do understand the table. But the braumeister have a limited space for the malt and if i use a "normal" (around 5,5 kg) wheight of malt the table is working. But if i really stuff the braumeister with malt (lets say 7 kg) conversion wont be as efficient since the flow of water (during mash) within the maltpipe will be heavily reduced and therefore the conversion will suffer.

And since the mash and boil is programmed in the braumeister before the boil, it's tricky to change the program during the brew. But if i want to prioritize the FG instead of the batch size a expected pre-sparge SG would be great for me, since i then can add some extra sparge water if SG is high and remove som sparge water if SG is low.

The other way around for me is to create lots of equipment profiles with different efficiencies based on how much malt i aim to use which is what i'm doing today. But it takes time to build a library of profiles.

bhe said:

english is not my native language since i'm from Sweden.

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Ah! I'll take that context into consideration.

Yes I do understand the table. ... But if i really stuff the braumeister with malt (lets say 7 kg) conversion wont be as efficient since the flow of water (during mash) within the maltpipe will be heavily reduced and therefore the conversion will suffer.

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That really shouldn't be a factor. I don't know why it is. A traditional mash doesn't move water at all and the conversion rate is the same no matter what the grain weight. The difference is in how much more water is absorbed and how well the grain drains. The gravity should be relative to the water to grain ratio during the mash.

The sparge isn't as effective as it would be with lighter grain bills. This is due to the weight of the grain compacting a bit more and the greater amount of sugar being pulled into the same amount of water.

But if i want to prioritize the FG instead of the batch size an expected pre-sparge SG would be great for me, since I then can add some extra sparge water if SG is high and remove some sparge water if SG is low.

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Here's where you confuse me. You don't need a sparge calculation, you need the dilution tool.

Sparge assumes you're rinsing more sugar into the kettle as you gain volume. Sparge starts as high as 26% sugar and ends as low as 2%, s although some dilution happens, extraction efficiency goes up and the run off always has some sugar content. Dilution is simply adding water to get the desired gravity/volume based on first runnings.

The other way around for me is to create lots of equipment profiles with different efficiencies based on how much malt i aim to use which is what i'm doing today. But it takes time to build a library of profiles.

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Yes! But not that much time. You can always modify the profile as you brew based on your observations. Then rename the profile and click the disc icon next to the name in the recipe view. The profile will be saved to the database under the new name and the old one will be there, as well. As fast as you learn your brewing system, you'll create appropriate profiles for each situation.

I guess you know how a braumeister looks inside, right.

Consider this (sliiightly exegerated though):
Lets say you have 4 kg of malt that you squeeze to the size of an orange. You then throw that malt-orange into your, lets say 25 litres, water and run the mash. And during the complete mash the malt will have the size of an orange. Du you think you will have the same conversion as if the malt was allowed the spread evenly among the water? Nope...

In a BM you have a fixed space for the malt, which is a lot less space then what the water and malt have together. The BM depends on circulating the water through the mash-pipe with the mash within it. So when using more mash the circulation will be slower than normal. The preasure from the pum will also form channels in the malt where the water flows a little easier and the malt closest to the channels will have better conversion while the malt further away from the channels will have a little more poor conversion. Speidel have partially solved this with have pump pauses which makes the malt fall down in the malt pipe and build new channels when the pump restarts. But with plenty of malt, the malt will not collapse down during a pump pause.
This problem is partly solved by pausing the BM unscrew a hot wingnut, remove the top filters and stir the malt. I do this a number of times during each rest. And i also take SG readings during each rest. If i had a the pre sparge SG value i would know if i'm closing in to the expected SG and then could skip the stirring (and burning fingers ).

When it comes to the sparge/dilution. Sure that might be fine if the wort actually needed på be diluted after a sparge, but what if the wort needed to be thickened? Then I have already sparged way too much. Du you get it? There are good reasons to have a expected pre sparge value. Then you probably say "But you can boil down the wort", but that isn't very conveniant when you already have a program running on the BM with a set time of boil and several hop additions in the BM timer.

Profiles then. Yup it's easy to create different profiles, but it takes lots of experimental brewdays until you have a nice set of profiles.

Well, well. No matter what you say, a expected pre sparge SG value would make me a little happier
And thanks for putting down effort with my question, it's appreciated.