Beer boiling or simmering

[Cellar_Rat]

This may be an old chestnut – but here goes anyway

Does anyone know - or - has anyone done any tests to prove whether beer needs to be continuously boiling are or just simmering?

The reason I ask, is continuously boiling is quite hard to achieve electrically. Most boilers control the temperature by cutting in and out (albeit very quickly). The result being an intermittent boil.

If you use a gas boiler however, you can turn it down until you get a continuous rolling boil.

Has anyone established if it makes a difference.

The reason I ask is because my boiler is a bit small but I'm trying to establish what the best way forward is.............

[lockwood1956]

Most boilers control the temperature by cutting in and out (albeit very quickly). The result being an intermittent boil

If you set it to 105Deg C it will give a rolling boil, the thermostat can be tweaked (Karl is your man in this regard, he used to make his living with such stuff)

everything i have read says it needs to be a rolling boil, but I have yet to see anywhere that tells me why!

regards
bob

[Cellar_Rat]

Yes. Rolling boil is where I am, and you are absolutely right if you can tweak your stat to 105.
But even @ 105 that's not a continuously rolling boil if it is electric

There is a bit in Graham Wheeler's book, touching on it being required for hop oil extraction, the question I'm really trying to answer is should I be using gas (less convenient but potentially better end product) or electric far more convenient and cheaper to run but at the cost of quality.

[lockwood1956]

I get a continuous rolling boil from my lidl boiler....not sure what the temp of stat is set to, as i tweaked it, but the wort boils in a rolling manner

[rjb222]

The way the boiling process was explained to me went like this. The conversion to the hop oils to bittering acids and flavoring acids this requires maintained temperatures. The separation of the proteins from the malts. The addition of Irish moss will aid in the drop out of the separated proteins.

[Cellar_Rat]

I feel some more reading coming on.............

[Delmonteman]

Rolling boil, lid off. You are also trying to drive off undesirable compounds such as di-methyl sulphide and its precursor whose name escapes me... Whereas DMS goes pretty easily you need to boil the QUACK!QUACK!QUACK!QUACK! off the one that comes before it which needs to get above 100C to be driven off... Simmering just doesn't cut it...

[Rich]

I've got an immersion heater in my boiler, thermostat bypassed. With the bent over end of the immersion in the middle of the pan it creates an almost volcanic effect in the middle. This is a little tamer on very cold days (I boil outside) but is helped by insulating the outside of the pan with a couple of layers of silver bubble wrap type insulation.

I'll try and get a pic of it next week if I remember.

[Cellar_Rat]

Where DMS and its friend, come from in the first place?

[rjb222]

Here is some material for you Cellar Rat. http://bavarianbrewerytech.com/news/boilhops.htm I hope this will help satisfy your questions. I am the same way I have to know why not just because every one else does it that way.

[Cellar_Rat]

Thanks for the link, I will have a read. I sometimes think it's a bit of an affliction I always have to 'know-why' not just the 'know-how'

[Cellar_Rat]

Although wasn't a bad read. I still don't have the answers I want. I think it is fair to say we need a good boil to extract the necessary hop oils, further it helps with sterilisation, tannin extraction from the whole, sugar inversion and PH stabilisation.

But I am beginning to think there is an no answer to this question of 'rolling boil' or 'thermostatic max boil' but a lot of Myth & misnomer

This extract refers to"Rapid boiling drives out oxygen, which can become very harmful in the process: it can change the color to darker than desired, and it can help serious infections to develop in the beer." ...... which I struggle with, given that we know yeast must have oxygen to work properly. Indeed after the boil the wort is chilled and then aerated before yeast is added!

Thanks for this link it has been a good read ... but the search continues ...

[rjb222]

Ok I do not know how answer the Thermostatic Question. The oxygen thing is I think easily answer like this. Above 80 deg. F the oxidation process is a major problem for beer. Oxidation and oxygen are different. Oxidation is actually the same process where ever it happens " IE" rusting metal. Oxygen is some thing that is needed for most things to live. So when he talks about boiling off the oxygen so the wort does not oxidize it is for the prevention of the Oxidization above 80 deg F. We then after the boil is done and the wort is below 80 deg F add the oxygen back for the yeast to use. This is done though stirring or an air stone some brave folks actually have a chart and use pure oxygen through a stone This one you have to be very careful with otherwise you again can oxidize your wort by adding too much oxygen. I hope this is what you were looking for.

[Cellar_Rat]

Oxidation is something that happens (normally browning -like cut apples) when something is in the presence of oxygen. Removing the oxygen stops oxidation.

I think the thermostaic question is going to be harder to answer

[Delmonteman]

S-methylmethionine is the precursor I was on about. It's produced from the kilning of malt.