Thoughts on this old porter recipe

[Zephyr259]

The following is from the durden park beer circle''s website. A couple of folks spoke about the recipe on these forums back in 2008 and said it was awesome, but neither member has been active for at least a year.

Plugging the details into brewers friend gives an og of 1.102 and 94 IBUs! I figure the higher gravity is due to BF assuming proper sparing where the recipe advises only using the first running. But the bitterness seems a bit OTT.

Any thoughts?

Original Porter (circa 1750)
O.G. 90

For 1 gallon (4.5lt):
3.5 lbs (1600g) Pale Malt
8 oz (226g) Brown Malt
8 oz (226g) Crystal Malt
4 oz (112g) Black Malt
1.5 oz (42g) Fuggles hops (4.5%)


Using a very stiff mash, mash grain for 3 hours at 150º F (66±1º C). Raise temperature to 170º F (77º C) for 30 minutes.

Sparge slowly with hot water at 180 - 185º F (82 - 85º C) to O.G. or required volume.

The first runnings from the sparge are best used for this beer (i.e. the highest gravity) in order to attain OG90. The further runnings can be used to make a lower gravity beer.

Boil with hops for 90 minutes.

Cool and ferment with a good quality ale yeast.

Mature for at least 6 months.

 

[Paddyg84]

Sounds interesting. Why mash for so long? And Yeh I think the bitterness seems a little high but it will need decent bitterness to balance the malt flavour.

 

[Zephyr259]

Sounds interesting. Why mash for so long? And Yeh I think the bitterness seems a little high but it will need decent bitterness to balance the malt flavour.

From their website:

Mash time. We often get queries regarding our mash times of up to 3 hours. It may seem strange at first, but it's all to do with quantity of scale.

Commercial brewers use very large volume mash tuns. They appear to mash for up to 2 hours and then start sparging with a very fine spray. Because of the time it takes for the spray to percolate down through their large mash volume, this is in fact a continuation of the mash for a further 1 or 2 hours, albeit at a higher temperature (170degs F).

We however, are only using comparatively small quantities, and the effective height of our mash is such, that the sparging liquid goes through it very quickly. So consequently we have increased the mash time, to imitate the length of time the grist is in contact with the sparge water. Sometimes we also suggest raising the mash temperature for the last hour, again to imitate the higher sparge temperature.

Although our archive research shows that commercial brewers had a much shorter mash time than the mash time given in our recipes, in order to re-create these beers as close as possible to how we believe they were, we devised this longer mash period for our small scale brewing.

I'm dubious as to the benefit of this, from my limited research, conversion is conversion, as i'll be using a grainfather from now on I'd just be mashing in that as normal.

 

[Hoppyland]

Well, I can't be bothered to put the volume & hop bill into a calculator, but I'd be very surprised if you'd get 94 IBUs out of that.
The long mash time goes against everything I've read. If the temperature is right, and the mash is thoroughly mixed, then surely you'd get good extraction way quicker!
Plus, if you leave it much longer, don't you start to extract things you wouldn't want - tannins etc??

 

[Zephyr259]

That's what I'm thinking too regarding the long mash, and just a bit of a waste of time when it'll be converted in an hour.

42g of 4.5% hops in 4.5L final volume (7.5 pre-boil) for 90 min boil gives 94 IBUs according to brewer's friend.

It also looks like a lot of speciality malts for 4.5L, especially the black malt...