Why a 90 min Mash vs a 60 min Mash?

[RukusDM]

Yesterday I brewed a Harp Clone from a book of Clone recipes my daughter gave me for Christmas.

The recipe called for a 90 Min Mash and a 90 Min boil. This is the first time I've seen that.

What might the reason be to have a recipe that uses a 90 min mash and boil, verses a 60 Min?

I did this BIAB and my efficiency was about 76%, so it did help in my situation, but for the more experienced guys here using good equipment, I don't understand how it might help them.

 

[Carter1932]

My experience has been that calls for longer mashes generally mean you are simply taking a bit of extra time to try to extract every last simple sugar from the mash.

90 min boils are usually called for when a recipe calls for Pilsner malt. The extra 30 minutes allows the boil to push off DMS (dimethyl sulfide). DMS is common side effect of using Pilsner malt. Without the extra boil time the beer might end up with some sulfur smell and taste.

 

[jldc]

90 min mash is to create a more fermentable wort. 90 min boils are usually used with Pilsner malt to boil off DMS, although some people like them for everything (it may just work better for your system).

L

 

[stevedasleeve]

DMS. If you don't like this flavor (I don't) you'll do a 90 minute boil most of the time and always for light colored beers.

 

[FatherJack]

I'm about to jump into all grain brewing, and starting off with a lighter ale for my maiden AG brew.

Would it be wise if I did a 90 minute mash and boil with it? I haven't put my grain bill together completely, but it is going to be a rather pale ale.

 

[RukusDM]

Thanks guys for clearing this up for me.

I just noticed that I had entered the wrong OG value into Beersmith. I actually got a 80% efficiency. I've never had a efficiency above 75% before and it appears that a 90 Min mash would also help me with my BIAB method.

I also did a Iodine test after the mash and that showed that I got good conversion.

I may elect to do 90 / 90 all the time until I get my cooler setup as a mash / lauter tun.

Thanks again

 

[Carter1932]

A 90 boil really isn't needed when Pilsner isn't a part of the mash, unless you are doing so to obtain a prescribed OG or net volume of wort.

 

[Yooper]

I'm about to jump into all grain brewing, and starting off with a lighter ale for my maiden AG brew.

Would it be wise if I did a 90 minute mash and boil with it? I haven't put my grain bill together completely, but it is going to be a rather pale ale.

No- you'll just make a more fermentable wort and you'll risk a darkening of the wort in a 90 minute boil.

90 minute mashes aren't very common for me- but for some beers with lots of adjuncts, you may need a longer mash. Or if you mash at cooler temperatures- like 147, it might be a good idea to let it sit for 90 minutes. Otherwise, 60 minutes is more than enough.

For the boil, if you're not using a ton of pilsner malt (with the DMS issue) and you're not trying to boil down a huge volume, in most cases 60 minute boils are sufficient.

 

[WhiskeySix]

I'm glad I read this. I just ordered my first all grain kit from NB. It's their Limited Edition Biere de Table. 8 lbs Pilsner, 1/2 lb Gambrinus Honey Malt. I will boil for 90 minutes.

 

[RukusDM]

No- you'll just make a more fermentable wort and you'll risk a darkening of the wort in a 90 minute boil.

90 minute mashes aren't very common for me- but for some beers with lots of adjuncts, you may need a longer mash. Or if you mash at cooler temperatures- like 147, it might be a good idea to let it sit for 90 minutes. Otherwise, 60 minutes is more than enough.

For the boil, if you're not using a ton of pilsner malt (with the DMS issue) and you're not trying to boil down a huge volume, in most cases 60 minute boils are sufficient.

Yooper, I have a few other recipes that call for a Lager Malt. Does that also have the DMS issue like the Pilsner malt?

 

[davesrose]

I think it should also be mentioned that 90 minute boils aren't just used for driving off DMS: it's also used for hop utiltization. It isn't just Dogfish Head IPAs that go above 60 minutes for their hop boils, but I've also had German recipes that call for a 120 minute boil with their bittering hops. I suspect this is a way to make the bittering hops to become more mellow and help accentuate some crispness: I haven't done an IPA yet that calls for 120 minutes....but I have had several that start at 90 minutes.

As far as malts, though, I'm not sure if a 120 or 90 minute boil does much with a typical modified malt bill. I could see maybe unmodified malts that might need more duration to clear up some proteins (but then you have an issue of if you did a protein rest with those...).

 

[RukusDM]

Thanks

 

[bob1852]

I believe it was the great EdWort that says he sometimes does 90-minute mashes because it gives him more time to do other stuff.....(maybe not beer related; aka, adjust the smoker, clean the garage, etc.).

I sometimes do 90-minute mashes if I don't get my sparge heated up quick enough, or if I am doing other stuff....

 

[bullinachinashop]

The longer mash will also give you higher attenuation.

Very beneficial for a dry beer.

Bull

 

[stevedasleeve]

I think it should also be mentioned that 90 minute boils aren't just used for driving off DMS: it's also used for hop utiltization.

Well you can always up the hops to get the same IBUs at (say) 60 mins. At least if you believe bitterness calculators (I don't) ...!

 

[bh10]

The longer mash will also give you higher attenuation.

Very beneficial for a dry beer.

Bull

Ive heard a couple times before.

 

[sjbeerman]

90 minute mashes are generally required for mash temps less than 150 F to allow full conversion. For mash temps equal to or greater than 150 F, the conversion is usually complete in 45-60 min.

 

[RukusDM]

90 minute mashes are generally required for mash temps less than 150 F to allow full conversion. For mash temps equal to or greater than 150 F, the conversion is usually complete in 45-60 min.

This recipe from the Book wanted a 152 Deg Mash for 90 Min. I didn't think to do a iodine test prior to the 90 min. I did do one after the 90 min Mash though and it showed good conversion.

 

[RM-MN]

The thickness of your crush also plays into this as it takes more time for the enzymes to work on thicker grain. As you crush finer and finer, conversion happens faster but then you have the problem of a stuck sparge as you have such fine particles that they clog the strainer.

If you work more with brew in a bag, you can crush or even grind the grain quite fine and get your conversion quicker but still get the liquid separated from the grain as you have a large area of very fine mesh for it to seep from. Try a fine grind sometime and check your conversion after 15 minutes. I did my last for 30 minutes and did a small sparge through my bag of grain and still got 78 % efficiency. I tasted the mash at 15 minutes and it was already quite sweet.

 

[ArcaneXor]

Yooper, I have a few other recipes that call for a Lager Malt. Does that also have the DMS issue like the Pilsner malt?

Most common lager styles are Pilsner-based, so maybe that's what they mean by lager malt.

 

[RukusDM]

Most common lager styles are Pilsner-based, so maybe that's what they mean by lager malt.

Thanks, I hadn't seen a malt called "Lager Malt", only Pilsners at my local.