Scaling quantities - "liquor" and "makes" volumes

[Dulwich North]

I am trying to scale down a recipe for my 11L pan and just need a bit of guidance about "liquor" and "makes" volumes. Maybe I have understood, or maybe I need pointing in the right direction....

Since it's a popular book, I'll say that I am scaling down the Belgian Tripel recipe in the 2019 edition of Greg Hughes Home Brew Beer. I see that it makes 23 litres, I6.3 litres is shown as the mash liquor and 27 litres for the boil liquor. So what I think I understand is that after mashing with 16.3L, I would use up to 10.7L sparging water to get up to the 27L to begin boiling. Right so far?

In my 7 brews to date, I am seeing about a third of the volume being lost in boiling - I'm doing 60 mins in an open pan. So that 27L would head down to 18L, well short of the 23L that the recipe makes. So at this stage would I just be making up the difference with boiled water or topping up the fermentation vessel. I must be missing something here!

 

[jMac]

One thing I will say is that I had much larger, proportional boil off losses when I was doing small batch brews in an 11L pan than I do now doing full length brews in a 32L kettle.

Essentially, what I’m saying is that your system losses can only be accurately measured by you on your own equipment, brewing to whatever length you are doing. The GH book is just making an assumption on an average sort of boil off rate based on the sort of standard equipment someone brewing 23L might be using. If you want to reproduce any recipe exactly they will need recalculating based upon your own equipment/system profile/brew length.

 

[Dulwich North]

Thanks. So as I'm losing a third, to get to that final 23L I'd be boiling 34.5L. Is that any better than topping up at the end of boiling or into the FV?

 

[MmmBeer]

The quantity of mash liquor is based on a ratio of liquor to grain, in this example 2.5 litres of liquor per kg of grain (anything up to 3 l/kg is common).

Your total losses are a combination of what is absorbed by the grain, the boil evaporation, the hop absorption and anything left in pipes, pumps, vessels etc. (which is probably negligible in your case).

For what you are trying to do, the easiest solution is to halve all quantities and aim for 11.5 litres, but allow say a half litre extra sparge liquor to compensate for additional losses. Then when you transfer to your FV, note how much wort you have and as necessary adjust in future brews.

Regarding topping up in the FV, this is not ideal, adding additional mash or sparge liquor will extract more sugars form your grain, adding it later achieve nothing and reduce your efficiency.

 

[jMac]

Thanks. So as I'm losing a third, to get to that final 23L I'd be boiling 34.5L. Is that any better than topping up at the end of boiling or into the FV?

Yes, as @MmmBeer says, if your losses are that high, it’s best to aim for a greater pre-boil volume by sparging until you have collected what you need - you should then, after your boil losses, end up with the correct post-boil volume in the FV at the correct OG. Topping up during the boil or after is just going to dilute your beer.

However, I don’t think you’d find your losses to be that high if doing a full length 23L brew. What is your brew length btw? You’re using an 11L pot, so are brewing small batch 4/5L? Do you use any brewing software? That makes it so much easier to scale a recipe taking into account your personal equipment profile.

 

[Dulwich North]

Thank you, both. That pre-boil logic makes sense. So assuming I still lose slightly more during boiling, is a slightly stronger beer the worst that can happen? I can live with that outcome.

I've done a couple of 9L batches in the pan and will probably do that for this Tripel. As for brewing software, not yet, though I have been looking at Brewfather and Brewers Friend to see how they might help. I suspect I'll find them useful once I've got a bit further on, but right now I'm still trying to get some basic concepts.

 

[terrym]

Thank you, both. That pre-boil logic makes sense. So assuming I still lose slightly more during boiling, is a slightly stronger beer the worst that can happen? I can live with that outcome.

I've done a couple of 9L batches in the pan and will probably do that for this Tripel. As for brewing software, not yet, though I have been looking at Brewfather and Brewers Friend to see how they might help. I suspect I'll find them useful once I've got a bit further on, but right now I'm still trying to get some basic concepts.

If its any help I have an 11 litre pot which I use for mashing and the boil. The pot just fits in my kitchen oven and I can control mash temperatures really well using a low setting on the oven. I batch sparge in a separate 15l FV. The boil volume is 9 litres and I just top up any evaporation losses as the boil progresses.

 

[jMac]

If its any help I have an 11 litre pot which I use for mashing and the boil. The pot just fits in my kitchen oven and I can control mash temperatures really well using a low setting on the oven. I batch sparge in a separate 15l FV. The boil volume is 9 litres and I just top up any evaporation losses as the boil progresses.

So, do you just maintain the 9L for the duration of the boil, so your gravity doesn’t change but you get the hop utilisation? I’ve heard of kettle top-ups, but never really understood them.

 

[terrym]

So, do you just maintain the 9L for the duration of the boil, so your gravity doesn’t change but you get the hop utilisation? I’ve heard of kettle top-ups, but never really understood them.

That's exactly what I do. Prior to brewday I punch all the recipe numbers into the BF calculator adjusting the hop quantities to achieve the IBUs I am looking for. And its further complicated by the fact that about half of my brews are partial mash so I dilute the wort in the FV with water and some or all of the DME. It might not be for the purists but it works for me.

 

[Dulwich North]

The boil volume is 9 litres and I just top up any evaporation losses as the boil progresses.

Thanks, that sounds like a plan. With this ale's long conditioning period coinciding with Christmas, I'm keen to get it going.