Water To Grain Calculation ?

[Renegade]

You also need to allow for the extra trub generated by BIAB, somewhere in the order of 4 litres overall should cover that.

Hang on, are you suggesting that post-fermentation trub would be to the 4 litre mark ? That would bury my tap !

 

[rupal]

Thank you everyone for the great help. I might do a test boil as "Thirsty Boy" suggested, and hopefully do my brew over the weekend. I will post back & maybe with some pics.

Rupa

 

[Thirsty Boy]

I notice that some people (including you IIRC) measure evaporation in L/hr, whereas beersmith has %/hr. The former makes a lot more sense to me. Why use the latter?

T.

Almost the opposite - I am one of the few defenders of the % evaporation rate.

The reason its used in all the brewing software, is that % evaporation rate is one of the traditional ways of measuring your boil's effectiveness - not for calculating your volumes. You might have read that your boil off should be somewhere between 10 & 15% ?? those are the usual figures quoted.

That is per hour - and its a way of helping you to make sure that your boil is vigorous enough and doing everything its supposed to. Its not particularly about calculating your volumes.

What you do is - you do a boil, adjust it so things look right to you - and measure how much you boil of in an hour. If that amount is between 10&15% of your starting volume - then you are (likely to be) good to go and now the only figure you need to worry about is the actual amount in litres. If its less than 10% or more than 15 .. you might want to think about adding or subtracting heat.

If you only ever brew the same volume of beer (or within a few litres) then you never need to worry about it again - but if you change the size of your boild drastically, like going to double batches, then its something you might want to re-visit.

I change batch sizes reasonably regularly and I try to make sure that no matter what size batch I am making, I boil off around 15% of the starting volume - I will adjust my flame, adjust my effective surface area and change my pot if need be, to make sure I do.

Boil intensity is something I want consistent in my brewing - I can control it and I want to... the % boil off figure is one of the tools I use to effect that control.

 

[Nick JD]

Do these numbers make sense for a mini BIAB AG?

In a 15L kettle, mash 1.5kg of grain with 10.5L of water to end up with a 7L wort?

If I add more grain, I'd get a higher gravity and a higher alc% - at what point would I lose efficiency? At some point will I just be leaving maltose-logged grain behind?

(I know it probably sounds nuts to do such a little brew, but I like variety/experimenting and lack the equipment/space to go bigger)

 

[smollocks]

Nick - That's about right, you'll probably lose 1L to grain, 1L to trub, and 2L to evaporation. You might actually end up with less than 7L, but that doesn't matter - measure the gravity of the wort at the end, and if it's higher than your target you can simply add water to adjust. Beersmith can tell you how much water to add.

I'm starting to realise that starting water estimates are just that, they don't really need to be highly accurate. If you start with not enough water (i.e. ending up with high gravity wort), you just add water at the end to adjust to your target gravity. If you start with too much water (i.e. ending up with low gravity wort), you just extend the boil a bit longer to evaporate more water.

If your water is out by an order of magnitude you will of course affect your hop utilisation, but as long as you're in the ballpark it will be fine. Take notes of evaporation rates and trub losses, and your predictions will improve over time.

 

[Nick JD]

Nick - That's about right, you'll probably lose 1L to grain, 1L to trub, and 2L to evaporation. You might actually end up with less than 7L, but that doesn't matter - measure the gravity of the wort at the end, and if it's higher than your target you can simply add water to adjust. Beersmith can tell you how much water to add.

I'm starting to realise that starting water estimates are just that, they don't really need to be highly accurate. If you start with not enough water (i.e. ending up with high gravity wort), you just add water at the end to adjust to your target gravity. If you start with too much water (i.e. ending up with low gravity wort), you just extend the boil a bit longer to evaporate more water.

If your water is out by an order of magnitude you will of course affect your hop utilisation, but as long as you're in the ballpark it will be fine. Take notes of evaporation rates and trub losses, and your predictions will improve over time.

Thanks mate! I don't want to be chucking precious wort away because my little no chill vessel is too small. I'll adjust it for the second brew if it's over.

Whether the missus can get used to little bubbling fermenters littering the house is the next issue .

 

[drtomc]

Almost the opposite - I am one of the few defenders of the % evaporation rate.

Ah. Well.

Thanks for the informative reply.

 

[rupal]

I finally did my BIAB brew over the weekend. I did a mini sparge (as i described in my earlier post) & ended up with about 23l at end of boil. The SG was 1.085 & my Beersmith estimate was 1.095 (with 75% efficiency) So i got around 67% efficiency. One thing i noticed when i was draining the wort into the fermenter is that it's full of tiny white sedimenty stuff floating\suspended all through the wart, is that normal ?

 

[rupal]

AnyOne ???

 

[flattop]

Sounds like protein break material or something similar, i filter my wort from the urn to the no chill vessel as it's easy to get the boil trub passing from one vessel to another.

 

[Thirsty Boy]

I finally did my BIAB brew over the weekend. I did a mini sparge (as i described in my earlier post) & ended up with about 23l at end of boil. The SG was 1.085 & my Beersmith estimate was 1.095 (with 75% efficiency) So i got around 67% efficiency. One thing i noticed when i was draining the wort into the fermenter is that it's full of tiny white sedimenty stuff floating\suspended all through the wart, is that normal ?

67% efficiency isn't all that bad for a high gravity BIAB - you were never going to get 75% with a grain bill big nough to give you 1.095. I'm impressed you did as well as you did.

BIAB does result in more sediment and trub than brewing with a mash tun/lauter tun. Some people dont worry, but its my opinion that on the way to the fermenter isn't where you should notice it - you should notice it in the ketle after the boil... and leave it there along with the hot break and hops.

Thats one of the trade offs of BIAB - you get (in general) uch better efficiency than you would think for a no-sparge technique - but you lose a little more to kettle trub than other methods. It still balances in your favour over all, but there is a little cost to the benefit.

The only reason I would be concerned at all - it will mostly all settle out in the fermenter anyway, dont worry - is that with a beer of that strength, you will need to age it before its much good no matter what. And dirty wort into the fermenter is an issue for aging beers.

So - in general - no probs, everything is good. BUT in future, when you are making a beer you know you are going to have to leave around for a while before you can drink - its worth taking extra care to be really really clean and careful to only rack very clear wort to your fermenter. You don't want your beer to stale before its even matured. Sure, you lose a bit extra on the way - but this is a long term high value investment we are talking about... don't be stingy.

But remember - it'll all be ok for now, no need to stress at all.

tb

 

[flattop]

TB is right, i did a "dunk sparge" for my first few brews and got a worse efficiency than with no sparge, i changed my stirring paddle to a Bunnings paint stirrer and increased my efficiency heaps, I'm talking about the potato masher kind of stirrer. IMHO Stirring the grain well and regularly will actually make for a better extraction in BIAB than a sparge.
Efficiencies seem to be slightly less in BIAB than traditional but don't sweat it, taste the beer, if it's good don't worry about numbers.

 

[rupal]

Thanks. I actually noticed the sediment floating through the wort when i was racking it into the no-chill cube (as i was looking into the kettle). I racked into fermenter & pitched starter Yesterday arvo, & by around 7:30 pm the blow-out pipe\air-lock was already bubbling away. When i took a gravity reading this morning (1.055), i noticed the sedimenty stuff was still there, it seems to be suspended in the wart without sinking....... I think i might brew something a bit more simple soon like a WitBeer, as the "Westvleteren 12 Clone" i just did will take a long time to mature.

cheers - Rupa