Can I top up with all-grain recipie?

[Rosshedley]

Hi Brewers,

I am thinking of purchasing a 2 gallon brewing batch kit (all-grain). It recommends 20 Litre pot to brew in, but I only have 11L. Could I brew in this (obviously adding all ingredients) and then just top up required amount of water when adding to fermentation vessel and pitching yeast?

Cheers,

Ross

 

[balrog]

Absolutely.
There are some slight hop utilization changes when boiling a higher gravity wort, as doing a "partial boil" method, which is what you are talking about. You'd mash with enough water so that grains & water fit the 11L pot without overflowing (see several online calculators to help, I like Pricesless, but I also like BIAB), then maybe sparge a little so you boil as much as you can leaving space for first hot break, without boil over (this can be mitigated some by using FermCap type anti-foaming agent) then add the water necessary to make the desired OG.

 

[Rosshedley]

Great - yes I would be looking to boil in bag. I will look for one of those calculators to determine starting water volume of brew then. As I am using BIAB method (and therefore not sparging) will calculator account for that and leave me enough room for hot break without boil over?

Thanks,

Ross

 

[pvpeacock]

Yes. From time to time, I like to brew 10 gallons even though I only have a 7 gallon brew kettle. I just use a 10 gallon recipe for grains and hops, but use less water in the mash and boil to brew essentially a high gravity beer. Then, I split the wort between my two fermenters and top each off to 5 1/2 gallons. Many commercial brewers do something like this -- they brew and ferment a high gravity beer and then dilute it with water at packaging to increase the volume, reduce the alcohol and adjust the flavor. Coors used to ship high gravity beer fermented in Golden, CO by rail to Virginia to be blended with Virginia water and bottled/canned/kegged. However, to avoid oxidation as a home brewer, it is better to top off before fermentation.

 

[McKnuckle]

Mashing with full volume takes more space than boiling. So if you are planning to do a full volume mash in this 11L kettle for a 2 gallon batch, you will not fit it in there.

I'm going to just throw some numbers out, and you can use one of those calculators to see for yourself how it works.

If you want to end up with 2 gallons in the fermenter, factor in grain absorption and evaporation to come up with your total water. Let's say your kit has 4.5 lbs of grain. It will absorb about 0.4 gallons of water. Your small kettle on the stove, for example, may evaporate about 0.5 gallons per hour.

So you are losing 0.9 gallons during the brew. Add that to the batch volume of 2 gallons, and you have 2.9 gallons of total water required to brew the beer. That's essentially 11L. So even the water alone won't fit.

The grain itself will occupy about 0.36 gallons of volume in the mash. So a full volume mash for this situation will require 3.26 gallons of volume. You're way over.

If you reserve a small amount of the water - exact amount is NOT the least bit critical, just enough to make the mash fit without a mess - you can do a pour-over sparge at the end. After mashing, you would lift the bag out, place it in a colander placed over the kettle, and pour the reserved water over it into the kettle, rinsing the grains.

Then you'd be ready to boil. However, you will have about 2.5 gallons in the kettle. It'll be too darn close for most of us. Boilovers suck, especially on a stove. So you should probably withhold that water for AFTER the boil INSTEAD of doing the pour-over sparge. You would keep it cold, and just add it to the hot wort at the end to help chill it.

It is useful to work through the options using real numbers. I hope this helps a bit.

 

[balrog]

What @McKnuckle did with numbers is what I went quickly through with the Priceless calc.
You have to know your boil off when you use YOUR pot with how vigorous YOU boil. Keep in mind that a rolling boil is sufficient, if the water keeps rolling a bit, it's a rolling boil. No volcanoes required.

I would personally aim for having a good 6-8cm space left above liquid in the pot
And just have a spray bottle with water handy as the wort comes to a boil, spraying the foam to knock it down.

But the water calc, and there are many, will help you find what you need for water, and show you the total volume of mash water and grains that will fit in 11L. And don't fill it to the rim. You will regret it. With the priceless calc, just put in the boil off rate you have (you will have to test this to find it; boil with pot as full as you plan to fill it in reality, boil 30m, find what evaporated, double to get 60m boil off), put in the amount of grains, then adjust the sparge amount until the mash water and grains will fit. That sparge water is the amount to withhold from the total water. You'll either rinse as per @McKnuckle , or top up the fermenter with that amount after the boil. Even refrigerate that amount and add it to help chill the boil faster.

 

[Rosshedley]

Thanks everyone - super helpful as ever! I have just realised I do have a 20L pot...d’oh! But good to know the above anyway!

Thanks again!

Ross