90 Minute Boil

[boydak]

I am seeing some recipes that call for 90 minute boils. Some you don't add hops until the wort has boiled for 30 minutes. What is the reason for a 90 minute boil?

 

[balrog]

It does a couple of things, primarily reducing water, increasing SG. Longer boils are traditional for Pilsner malt heavy recipes, traditionally thought to drive off the increased DMS (canned corn) precursors that Pilsner malt has over std 2-row or 6-row malt. Also, 90m boils are good for getting more maillard reactions and makes porters/stouts richer.

 

[VikeMan]

Longer boils are traditional for Pilsner malt heavy recipes, traditionally thought to drive off the increased DMS (canned corn) precursors that Pilsner malt has over std 2-row or 6-row malt.

Just a nit... it's not the precursor (SMM) that's driven off, it's the actual DMS. The heat converts the (non-volatile) precursor to (volatile) DMS, which then boils off.

 

[boydak]

I found an American Wheat recipe that calls for 90 minutes, does that make sense? 20% of the grain bill is Pilsner.

 

[davidabcd]

It does a couple of things, primarily reducing water, increasing SG. Longer boils are traditional for Pilsner malt heavy recipes, traditionally thought to drive off the increased DMS (canned corn) precursors that Pilsner malt has over std 2-row or 6-row malt. Also, 90m boils are good for getting more maillard reactions and makes porters/stouts richer.

Squeeze in an extra beer in that thirty minutes as well.

 

[VikeMan]

I found an American Wheat recipe that calls for 90 minutes, does that make sense? 20% of the grain bill is Pilsner.

You could certainly reduce that to 60 minutes. Keep in mind that a shorter boil means using less total water and therefore having a lower mash efficiency (compared to what it would have been with more water in the mash/sparge), thus needing a larger grain bill.

Of course, this is all relative... if the recipe you are looking at lists specific grains weights (instead of percentages), you'd want to convert for your own expected efficiency even if you weren't changing the boil length.

 

[balrog]

My first reaction is same as Vikeman, I'd def do a 60m boil.

 

[cire]

90 minutes is still the norm at many UK breweries. Before nodern malts it was 2 hours. Some breweries boil for 60 minutes, but were in a minority until recent times.

60 minutes duration is usual when boiling under pressure with superheated steam as the power source. In those cases the boil is turbulent at the start and sometimes the end, but mostly only a simmer, although at a much higher temperature than at normal atmospheric pressure and restrained venting.

 

[Francus]

It also boils off polyphenols which can give a band-aid sort of taste to the beer. Make sure you boil with the lid off or most of the nasties you are boiling off just fall right back into the wort. I almost never do less than a 2 hour boil and never less than 90 minutes. And as mentioned above, it allows you to squeeze in an extra beer while waiting. I usually don't do my first hop addition until 60 minutes are left on the boil.

 

[VikeMan]

It also boils off polyphenols which can give a band-aid sort of taste to the beer.

Polyphenols are non-volatile and don't boil off.

 

[Francus]

Either way, that is what I was told by a brewer 30 years ago. And lots of nasties do boil off if not that one. And I am not convinced they don't boil off. I will have to do some research.

 

[VikeMan]

And lots of nasties do boil off if not that one.

DMS does. Some aldehydes do. Hydrocarbons (hop aroma compounds) do, but that's not generally considered a good thing.

 

[BrewnWKopperKat]

I found an American Wheat recipe that calls for 90 minutes

If the recipe is from a source you trust, consider following the recipe the first time you brew it.

Also, 90m boils are good for getting more maillard reactions and makes porters/stouts richer.

FWIW, I have a couple of dark / malt forward recipes where I played with boil time. For my taste, longer boils for these recipes resulted in more enjoyable beer.

For hop forward styles and shorter boil times, I wonder if one could make an enjoyable clear-ish beer using just brewers crystals . It could be an interesting "no-boil"/"hop sampler"/"malt sampler" exBEERiment .

 

[balrog]

There's entire rafts of threads on such no-boil hoppy things. DME only w cold water; all-grain heated just to 170 to pasteurize then whirlpool; etc.

 

[BrewnWKopperKat]

But I haven't seen one where just brewers crystals were used. Don't know if it's a good (or bad) idea. Might be something to brew "on they side" during a long mash / long boil brew day.

 

[Vale71]

It also boils off polyphenols which can give a band-aid sort of taste to the beer.

It's actually clorophenols and since they have boiling points that lie around 200°C I doubt you'll be able to boil them off unless you're boiling in an autoclave at an extremely high pressure/temperature combination.

 

[porterguy]

... which can give a band-aid sort of taste to the beer.

Okay, how many people out there have really tasted band-aids? Ahh, I see the same hands as those that have smelled (and tasted?) "horse blanket".

 

[mashpaddled]

A lot of homebrewing lore began by taking advice from pro brewers or pro brewing books without modification for our smaller size and evolution of the ingredients available. One of those subjects is that pilsner malt requires a ninety minute boil to boil out SMM to prevent DMS.

The length of the boil is an issue to ensure sufficient time to volatilize the SMM and sufficient movement of the wort to get the volatilized SMM driven out of the wort. A large commercial boil needs more than a six gallon boil to accomplish that. With well modified pilsner malt that is even less of an issue. Unless you have a particularly large brewing system or you are using primarily undermodified pilsner malt I wouldn't even think about wasting time with the extra thirty minutes. An extra thirty minutes of boil time doesn't add that much to a brewday but it's unnecessary.

 

[day_trippr]

"Context matters"
A 90 minute prescribed boil time could simply be an efficiency thing.
Gathering up more sparged wort and all then boiling the heck out of it to hit the numbers...

Cheers!

 

[bracconiere]

"Context matters"
A 90 minute prescribed boil time could simply be an efficiency thing.
Gathering up more sparged wort and all then boiling the heck out of it to hit the numbers...

Cheers!

pretty much what i do, i boil for three hours......my next batch i'm going to boil for 3 hours and just do a 15 minute hop addition, at the end....

 

[VikeMan]

The length of the boil is an issue to ensure sufficient time to volatilize the SMM and sufficient movement of the wort to get the volatilized SMM driven out of the wort.

Just one pedantic nit...

It's not SMM that's boiled off. The heat from the boil converts (non-volatile) SMM to (volatile) DMS, which then boils off.

 

[yeastseeker]

I think that the 90 minute boil is a relic of the past that needs to go away. A 60 minute boil with about a 5% boil off rate will do everything you need it to without subjecting your wort to excessive thermal stress.

 

[Vale71]

A lot of homebrewing lore began by taking advice from pro brewers or pro brewing books without modification for our smaller size and evolution of the ingredients available. One of those subjects is that pilsner malt requires a ninety minute boil to boil out SMM to prevent DMS.

You won't find mention of 90-minute boils in any pro brewing book (well, not anything that was published after 1960 or thereabouts) so I'm guessing you might have got it backwards. The recommendation probably originated from pioneer homebrewers having inadequate systems that barely brought the wort to a boil, ending in poor hot break and possibly DMS off-flavors.

 

[InspectorJon]

Ask the LODO guys about long boils...but not here please.