1.5 kw heating element

[davidgrace]

I want to convert a 20L stainless steel pan into an electric boiler for boiling my wort. Based on the size of my small batches there is likely to be about 14-15L in the pan. How long would it take for a 1.5 kw heating element to bring that volume to the boil and would it sustain a rolling boil for 60 minutes? The boil will start at 65C.

 

[ppsmith]

That's going to depend on a few factors - the initial water temperature, the rate at which heat is lost from the system etc.

This seems to give some idea of the maths needed - How to Calculate Time to Heat Water

Assuming 15L starting from a tap temperature of 10 degrees (i.e. needs to gain 90 degrees C)

Pt = (4.2 × L × T ) ÷ 3600
   = (4.2 x 15 x 90) ÷ 3600
   = 1.575 kWh

t = 1.575 kWh / 1.5 kW
  = 1.05 hours

That's a minimum time of 63 minutes to get to boiling, although in reality it'll take longer than that as heat will be lost from the pan as you bring it to the boil.

Once it's at a boil, I think you just need to make sure that the power you're putting into the system is equal to the amount which is being lost to the environment.

(Based on my poorly remembered physics lessons - happy to be corrected if not)

 

[davidgrace]

That's going to depend on a few factors - the initial water temperature, the rate at which heat is lost from the system etc.

This seems to give some idea of the maths needed - How to Calculate Time to Heat Water

Assuming 15L starting from a tap temperature of 10 degrees (i.e. needs to gain 90 degrees C)

Pt = (4.2 × L × T ) ÷ 3600
   = (4.2 x 15 x 90) ÷ 3600
   = 1.575 kWh

t = 1.575 kWh / 1.5 kW
  = 1.05 hours

That's a minimum time of 63 minutes to get to boiling, although in reality it'll take longer than that as heat will be lost from the pan as you bring it to the boil.

Once it's at a boil, I think you just need to make sure that the power you're putting into the system is equal to the amount which is being lost to the environment.

(Based on my poorly remembered physics lessons - happy to be corrected if not)

Would a 2.4kw Element be a big improvement over the 1.5 kw? Or would the 60 minute boil with this element be too vigorous resulting in too much liquid loss to boil off?

 

[Brew_DD2]

You'd maybe be better off with a pot and an induction stove. Kettle elements are fine but they have a high watt density and tend to scorch quite easily (learned the hard way). Induction stoves can be picked up pretty cheaply on Amazon.

What is it you're hoping to achieve with you new setup?

 

[davidgrace]

You'd maybe be better off with a pot and an induction stove. Kettle elements are fine but they have a high watt density and tend to scorch quite easily (learned the hard way). Induction stoves can be picked up pretty cheaply on Amazon.

What is it you're hoping to achieve with you new setup?

I was on the forum last week over the issue of my Peco boiler boiling off too much wort (3.5L). You gave me some helpful advice. I am settled on just adding extra water to resolve this problem, but a friend advised me to pursue the possibility of an electrical boiler using a 5L stainless steel pan that I already possess. The idea is that it may boil off less than the Peco. I think I would be boiling about 14L for my 11L batch and the boil would start at just under 65C as I would still use the Peco for mashing.
Would this be adequate? About half the price of others on Amazon. Single Hot Plate Portable Table Top 1000W Electric Cooker Stove Kitchen Utensils | eBay

 

[Brew_DD2]

I still don't understand why you're seeing boil off as an issue. It's just part and parcel of the brew process. It's not positive or negative, it just is. If you mash in or sparge with more water then you'll hit your targets. Changing your equipment won't change the dynamics of brewing.

I can see you were asking similar questions back in May and you were given good advice. I'd really suggest saving your cash and do a little reading/watching YouTube to develop a better understanding of the brewing process. Your pocket will thank you for it.

As I said in the previous thread, your process sounded fine, I just think you need to plug your numbers into some brewing software otherwise you'll never understand or be able to predict what your system does.

 

[davidgrace]

I still don't understand why you're seeing boil off as an issue. It's just part and parcel of the brew process. It's not positive or negative, it just is. If you mash in or sparge with more water then you'll hit your targets. Changing your equipment won't change the dynamics of brewing.

I can see you were asking similar questions back in May and you were given good advice. I'd really suggest saving your cash and do a little reading/watching YouTube to develop a better understanding of the brewing process. Your pocket will thank you for it.

As I said in the previous thread, your process sounded fine, I just think you need to plug your numbers into some brewing software otherwise you'll never understand or be able to predict what your system does.

I was settled on the route you are advising but two things happened to unsettle me. 1. To make progress I watched videos on using brewfather. I then started getting into brewfather scaling a recipe for 11L, but the hops were were wrong. People on the brewfather Facebook group discussed this and concluded that it was due to my unusual boil off at 3.5L. 2. A friend advised me convert a 20L pan I gave to a smaller capacity element to reduce the boil off. I feel a little embarrassed discussing this same issue with you, but the two masters above have thrown me. I know boil off is just part of brewing but mine seems unusually high.

 

[Brew_DD2]

I was settled on the route you are advising but two things happened to unsettle me. 1. To make progress I watched videos on using brewfather. I then started getting into brewfather scaling a recipe for 11L, but the hops were were wrong. People on the brewfather Facebook group discussed this and concluded that it was due to my unusual boil off at 3.5L. 2. A friend advised me convert a 20L pan I gave to a smaller capacity element to reduce the boil off. I feel a little embarrassed discussing this same issue with you, but the two masters above have thrown me. I know boil off is just part of brewing but mine seems unusually high.

3.5l of boil off in a hour isn't unusual. My boil off is 4.4l/hr. It's great to get advice, but I'd caution against taking anyone's advice as gospel (including me obviously).

I would say the advice you've been given isn't sound. Scale a recipe and then tweak it as you see fit to match the original recipe. You'll never clone a beer exactly, but where's the fun in that anyway? You're going to make a great beer regardless. We've all got lost in the weeds when trying to solve something we perceive to be a problem.

Going by what you've said in the other thread, your process is absolutely fine, it was just your water volumes were off. It's an easy fix and something you'll resolve through getting to know you're system, and not at all a problem you need to solve through equipment changes etc.

 

[Gerryjo]

As @Brew_DD2 says boil off is part and parcel of brewing and an induction hob would be a better alternative as that way you have control of your boil rate,no faffing about installing elements and the fact that you can decrease the power to a less vigorous boil which will help to reduce your boil off.Besidesbthe more you boil off you can liquor back to your original estimate of which there are plenty of calculators to help with this.

 

[Brew_DD2]

FWIW I brewed on a Peco for years and it served me really well. The only reason I eventually changed was because I seemingly turned into a magpie and wanted something shiny. The Peco is still going strong and had been kept as a backup.

 

[davidgrace]

As @Brew_DD2 says boil off is part and parcel of brewing and an induction hob would be a better alternative as that way you have control of your boil rate,no faffing about installing elements and the fact that you can decrease the power to a less vigorous boil which will help to reduce your boil off.Besidesbthe more you boil off you can liquor back to your original estimate of which there are plenty of calculators to help with this.

What do you mean by liquor back to your original estimate? Are you simply referring to adding water to reach the correct volume? And can you direct me to calculators to help with this?

 

[Gerryjo]

What do you mean by liquor back to your original estimate? Are you simply referring to adding water to reach the correct volume? And can you direct me to calculators to help with this?

Exactly as you say by adding water.if you have a higher boil off rate than your software profile is estimating it means you will have less wort with a higher gravity which then allows you to add back to the original gravity simply by topping up with water.
Try using this calculator as it's quite reliable and use it by checking your gravity with a hydrometer preferably.

 

[Nicks90]

What everyone else has said.
If you want 15l of wort in your FV, plug the numbers in and get it made.
If your boil is too vigorous and you only get 13l, then check the Og and water it down by However much a dilution calculator tells you - hopefully by 2l if your process follows your normal efficiency and numbers.

Regularly happens to me, as I have a 2.4kw tea urn and the boil is 'enthusiastic'
I keep thinking about adding a switch, as the elements under the urn are a 1.4kw and 1kw element in series. Idea was to add a switch to kill the 1kw element when it hits rolling boil, but never got round to it.

Now there is a difference in hop utilisation depending on gravity and volume, but you're talking tiny differences in the grand scheme of things when you are only back liquoring 10%. I bet you would be extremely hard pressed to notice any difference.

 

[Michael Burnley]

@davidgrace On brew day using brewfather there is a 'fermenter top up' option, this will work it all out for you