Biggest Boil Volume You Have Done In A 40l Urn.

[chadjaja]

The topic title says it all. I've done a search and still didn't the the answers I was after.

I have a 40L Birko urn and yesterday did a 32L boil which is a bit more than normal as I normally only brew keg size volumes. The urn still had a lot of headspace and if you are on the watch with a spray bottle and spoon boil overs can be avoided with a bit more in it. After the first point of bringing it to boil it should be fine from then on.

So how far have you pushed it in an urn?

Lastly I get a really good rolling boil with my camping mat on too, in fact I get a lot of evaporation so that shouldn't be a problem either imo.

 

[seemax]

Out of interest, does the Birko have a 2.2 or 2.4kW element?

Insulation (especially with Melb now in winter) is critical !

 

[Phoney]

8.2kgs of grain for a ~21L batch is about the biggest ive done. Of course, as with all batches over about 6kgs I reserve a few litres of strike water, heat it up on the stove and sparge the grains in a bucket with that reserve water - otherwise it wouldnt all fit in the urn during the mash.

 

[samhaldane]

I've been wondering about this too.

I'd love to be able to do double batches, brewing over gravity and ending up with 2 x 15L cubes (adding 5L in the fermenter).

I guess I'd need to start with 35L at the start of the boil (I get 3L evaporation over an hour, and leave about 2L in the bottom of the urn).

Has anyone done a boil that size successfully?

 

[chadjaja]

Sorry I should of pointed out I do 3V not biab....

And as far as the element I'm not sure but judging by yesterdays boil in a freezing garage I shouldn't have any trouble pushing it a few more litres.

 

[Bribie G]

Get yourself a bag, do a big grain bill then sparge in a bucket and add that back into the urn:

 

[C-MOR]

I have just acquired an urn (Vacola) and I am super excited about about my first ag batch.

I did a practice the otherday with water, it can safely boil 27L although i did ask my self 'what if i want more?.(27 becomes 25 ish after an hour, if my paying attention to the right info?)

How about topping up the boil as the volume reduces, with the kitchen kettle? (compensate for extra water in calcs)

then your final boil volume will be as much as you can possibly fit in the vessel, safely.

ps whats the spray bottle for?

 

[bignath]

I have just acquired an urn (Vacola) and I am super excited about about my first ag batch.

I did a practice the otherday with water, it can safely boil 27L although i did ask my self 'what if i want more?.(27 becomes 25 ish after an hour, if my paying attention to the right info?)

How about topping up the boil as the volume reduces, with the kitchen kettle? (compensate for extra water in calcs)

then your final boil volume will be as much as you can possibly fit in the vessel, safely.

ps whats the spray bottle for?

Not wanting to stray too far from the OP, but you'll be fine with 27l boil volume in your vacola.

My boiler is a 50lt keg (want to start doing double batches soon), but at the moment am only doing singles. My preboil volume is 25-26L and this gets me 20-22 litres cooled, into the fermenter. This is for beers around 4-5% ABV (starting gravity is usually around 1.048-1.052 - nothing crazy...)

Spary bottle of water helps with boilovers as the hot break is reached. Quick squirt as it starts climbing the walls can help control it from going over the sides. Not something i've had a problem with though obviously given my equipment.

 

[chadjaja]

I've been wondering about this too.

I'd love to be able to do double batches, brewing over gravity and ending up with 2 x 15L cubes (adding 5L in the fermenter).

I guess I'd need to start with 35L at the start of the boil (I get 3L evaporation over an hour, and leave about 2L in the bottom of the urn).

Has anyone done a boil that size successfully?

This is EXACTLY what I want to do. End up with two kegs worth for the same amount of time for one brew. Just got to work brewsmith to get the IBU's right for the hop utilisation taking into account the higher boil gravity and dilution at the end.

For picthing rates I'll just do a normal brew and then split the trub into two and pitch using that to get around a larger starter than my stir plate can hold.

If it was just 35L's I'd be fine but I get a much larger evaporation rate with my urn over the hour. Turning it down doesn't really work as it just turns on and off too much.

 

[trussyd]

I pretty consistently get a 26.5L batch out of a 30L urn. Pre-boil I just about have the wort to the brim, maybe about 10mm of head room. I occasionally make a bit of a mess but I'm doing it outside so it isn't too much of a problem, but it really doesn't happen as often as you'd think. By the end of a 60min boil Ive got enough to fill up a 25L cube and am able to get another 1-1.5L out of the trub for a starter.

35L out of a 40L urn should be doable enough.

 

[Goofinder]

I start with 31L preboil in my 30L urn which gives me about 26L after a 1 hour boil which is enough to get 22L into the fermenter after cubing. 31L in my 30L urn is just below the top opening for the sight glass, maybe 3cm from the top of the urn. The boil isn't particularly vigorous but it does the job. I have to watch it and scrape off the foam as it comes to the boil but once I've done that I can just leave it be and it won't boil over.

Or I should say that I used to do that, until I got my shiny new 70L kettle last week.

 

[Thirsty Boy]

The person who suggested topping up has it.

I would design your brew so your actual "pre-boil" volume and gravity equal what you mentally want your post boil volume and gravity to be. That is, a little over gravity, but by keeping the the pre-boil where you want the post boil to be... There are no mental gymnastics required during the boil... You are just aiming to finish where you started.

So say you want to finish the boil with 37L of 1.050 wort. Design your mash so you collect 37L of 1.050 wort in your kettle pre-boil. Note where it comes up to. If you think you need to, dip a little out into a jug/bucket while you get things boiling and the boil is settling down. Start your boil and as the liquid boils away, add back the reserved wort. Make sure all your wort gets boiled for at least 20mins though. Once you are out of wort, add boiling water... At the end of 60 mins, make sure the kettle is filled to the same height it was before you started... And you are left with 37L of 1.050 wort exactly the same as you started with.

Its just a way to do an over gravity boil - by using the post boil targets as your pre-boil, you both eliminate the need to do any fancy working out and you also know that you are being relatively conservative with the over gravity thing, so you aren't likely to bump into any quality issues as a result.

TB

 

[samhaldane]

If it was just 35L's I'd be fine but I get a much larger evaporation rate with my urn over the hour. Turning it down doesn't really work as it just turns on and off too much.

I used to get way more evaporation too until I ditched my camping mat, mainly because it kept getting sticky (I was doing BIAB then) and was a PITA to clean.

Have you tried without the mat?

 

[chadjaja]

Great idea Thirsty boy. Thanks for that thought and process. Might give both ways a try and decide on the easiest one to do.

I've been playing with beersmith and think I've worked out the process for the higher gravity boil ending with 30L's post boil of 1062 and dilute into two fermenters with 5L each to end with a SG of 1046 in each.

Still your way removes all the work to get to that point with the hop amounts and changed grain bill etc etc.

And yeah in summer I removed the mat as I lost too much to evaporation and had to top up post boil. Thinking I need it now in winter though and knowing exactly what I'll end up with post boil is a bonus. The first boil without it is a little like flying blind but for this process of getting the most out of my urn as far as volume wise its probably the thing to do. Having it on whilst bringing it to boil and then taking it off might be the answer.