Topping Up With Water

[nicklawmusic]

What's the deal with topping up a mini mash with water? I've read that you can't do it with all grain but you can with a mini mash. Why is that?

So, I have a stock pot that is 12 litres on total. Can I make a wort in this , boiling it off to around 10 litres and then top it up with water to 21 litres if I'm doing a mini mash? How do you work out the gravity without completely diluting the wort? And why can't it be done with all grain?


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

 

[chickypad]

You can top up with all grain, but most people don't because you want to collect all that as sparge water to get all you can from the grain. There are threads around by folks who mash a full grainbill in half the water then top up at the end due to boil kettle restrictions. With a mini mash you're only collecting part of your wort from mashing, the rest is made up of water and extract. You can only sparge so much, hence the reason there's usually some top up with a mini-mash.

 

[nicklawmusic]

So how do you calculate the starting gravity you want to reach?

For example, lets say I mash 2KG maris otter and boil 2.5 gallons wort, how would I know how much extract to add to reach, say, 1.040 and then accounting for the water dilution when topping up the wort at the end before pitching the yeast..... If that made sense.


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

 

[nicklawmusic]

I've brewed a couple of all grain beers, both of which I've been able to boil the full amount (2.5 gallon batches). However, I'm wanting to brew a five gallon batch without buying more equipment (for the time being).

I've heard that partial mash brewing is good if you need to top up your wort with water after the boil to reach 5 gallons, but can't seem to find much online about it.

Any suggestions?


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

 

[JohnSand]

I do the arithmetic, or use a calculator, like Brewer's Friend.
If your mash gives you 2.5gal of 1.048 wort, then you need to add 2.5gal of 1.032 wort to make 5gal of 1.040. That would be 1.9lbs DME, 2.2lbs LME. When I was doing this, I made calculations in advance, but usually made final adjustments after taking my OG measurement. A little water or a quick boil with some extract will adjust your gravity. But I also don't worry if it is close, say -2 to +4.

 

[nicklawmusic]

I'm terrible at maths. I have mathematical dyslexia so my brain can't compute figures.... But thanks for the advice.


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

 

[nicklawmusic]

How does adding gravity points together work? I can't get my head around 1.048 wort + 1.032 making 1.040. I'm sure I'm being thick but, as I said, Im numerically challenged.


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

 

[Yooper]

How does adding gravity points together work? I can't get my head around 1.048 wort + 1.032 making 1.040. I'm sure I'm being thick but, as I said, Im numerically challenged.


Emmanuales | #WhatWouldJesusBrew?
nick-law.com

When you add water plus extract, there is a dilution.

To make it easier, consider that you have 2.5 gallons of 1.050 wort from you mash. You want to end up with 5 gallons total, so you'll want 2.5 more gallons. Since you'll add extract, that will add some gravity points. So, if you take 2.5 gallons of 1.050 wort, and add 2.5 gallons of water (1.000), you'll end up with 5 gallons of 1.025 wort. That's simple dilution. Since dry extract will give 42 points per pound, a pound of it in 5 gallons will give about 8 gravity points.

So,

1.025 SG in 5 gallons. Add 3 pounds of DME and get approximately 24 more points= 1.049 (1.050).

This is much easier if you use something like Brewer's Friend, a free brewing calculator. I use it all the time. You put in the ingredients, and it tells you how much water to use and what the gravity points are.

 

[nicklawmusic]

Thanks. I understand it now. I've got BeerSmith on my iPhone but it's a bit too complex! I have used Brewers Friend; obviously didn't notice all the stuff about water.


Emmanuales | #WhatWouldJesusBrew?
nick-law.com