60 Vs 90 Minute Mash

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big d

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ive tried both so what is the advantage of one over the other.?
is sixty better than ninety or vise versa?
my mash books are very very limited.

big d B)
Ive only heard that a 90 min boil ensures that all the bittering to be got from the hops is completed.This apparently done around the 60 min mark so the 90 makes sure of it.

those who know for sure will be along soon!!! ^_^
i've always understood the whole reason you boil for 90minutes is so that you can get the hot break over and done woth before you start you hop additions.
Big D,
I asked a similar question on another forum and most people said that you get full extraction of fermentables at 90 mins where you dont get that happening at 60 mins.
I changed from 60 to 90 and I get at least 75% from each of my mashes, however I cant say exactly how much I gained because I changed the rollers on my mill, and from a false bottom to a manifold in the tun and as well as I played around with sparge temperatures all at the same time.
You know how it is when you first start grain brewing, you are flooded with information and until you get it all sorted out it is difficult to assess exactly what effect each change has on your beer.
Sorry i thought you where asking about the reason for a 90min boil ;)

As the belly said :p It has everything to do with extraction essentially the longer the mash the greater percentage of extraction. Except for the longer the mash the greater the chance of tannins appearing in your beer.

You can mash for 90 mins and still get no tanins. Perhaps you can mash longer but.............
Isn't mash duration determined by conversion state? i.e. we mash to convert starch to sugar.

If there are variables determining conversion rate, then time taken during one mash may be different to conversion time during another mash. (variables may include mash temperature??)

Wes Smith has written elsewhere about using diluted iodine tincture to measure conversion state. It's a good way to see what's happening in the mash.

Personally I always mash for 90 minutes to ensure full conversion. I don't test with Iodine and I am always within 2 points of my SG determined by Beersmith.
I have read that Barrett and Burston malt converts bloody quickly according to someone on OzCB, about 20 minutes I think IIRC.

My thougts and understandings are.... A 90min mash is more important when using malts with low enzymatic power and a low level of modicication (read: slower at converting starches to sugars). Most Australian base malts are high in enzymatic power and fairly highly modified malts. These latter malts convert quickly and can be done sometimes in 20mins (hence the need to hit your mash temp quickly, because if you stuff around for 10mins sometimes half the conversion can be already done and was it at your target temp?).

Longer mashes tend to be used with less modified malts and those with low enzymatic power, or in mashes with a lot of adjucts (the adjuncts contribute nothing in the lines of enzymes, hence fewer enzymes and a longer time for them to convert).

My understaning is that once conversion is complete, as viewed by the iodine starch test your mash is pretty much done but it's nice to leave it for a bit longer just to make sure you've got them all. Using a 60min mash with Australian base malts is plenty of time. I'm yet to have a mash not fully converted within this time using Aussie malts.

This isn't the gospel but I'm pretty sure this is the idea.

Cheers, Justin
That Nailed it Justin!

Hey TDA, Why don't you do a starch end point test?

Well it looks like back to the 60 min mash for me and I'll try the iodine test,
Any time saved on brewday is a bonus!


Oh fucken derr me...90 MASH not boil

I'll just shut up and sit in my corner

Go the saints( in both comps)
thanks justin
the reason behind my question was basically looking back over my ag brew notes the most stand out brew i have done so far was a 60 minute mash.the rest have been 90 minutes.the brew using amarillo hops as a trial done the other day was a 60 minute mash.knowing that aust malts are highly modified i reckon i will now use 60 as my main mash period.

big d
Mash time will vary according to the what your mashing, mash temp and grain to liquor ratio. Thinner mashes will convert more quickly than thicker mashes - they also favour beta over alpha activity.

Mashes at less than 65 deg need to be run for at least 90 mins, preferably more as the starch is not gelatinised and is not as accessible to the enzymes.

Generally the more kilned a malt is the less its diastatic power - it will take longer to convert. Of course a grain bill which contains a lot of unmalted material will need longer.

So, for me partial mashes with a grain to water ratio of 1:7 (no sparge) get 45 - 60 mins, full mashes with a ratio of 1:3 get about 75 mins for pilsner malt and about 90 for ale, Munich and Vienna malts.

Barret Burstons "Galaxy" malt is a very pale pilsner malt exported to East Asia. It has a very high diastatic power as it is meant to be used with a fair bit of rice I believe.

Iodine testing will also tell you what kind of sugars are in the sweet wort. No change in colour indicates short chain sugars, where deep reds and mahoganies indicate dextrins


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