First Partial Mash Brew

[shacked]

Hi guys,

After a bunch of kits & bits and extract brews I'm going to take the next step towards AG brewing by doing a partial mash.

My Mrs is away for the weekend, so I thought it was time to give it a go.

I was looking at adapting an AG Rye IPA recipe I found online and have a few questions about process.

Recipe
I wanted to use LDME as my base malt (3.85kg) and mash the specialty malts (about 2kgs):

RyePA (American IPA)

Original Gravity (OG): 1.060 (°P): 14.7
Final Gravity (FG): 1.015 (°P): 3.8
Alcohol (ABV): 5.89 %
Colour (SRM): 12.7 (EBC): 25.0
Bitterness (IBU): 60.7 (Average)

23L Total.

3.85Kg 66.51% Dry Malt Extract - Light
1.05kg 18% Rye Malt
0.5kg 8.49% Crystal 60
0.2kg 3.5% Carapils (Dextrine)
0.2kg 3.5% Wheat Malt

0.9 g/L Centennial (9.7% Alpha) @ 60 Minutes (Boil)
1.3 g/L Cascade (7.8% Alpha) @ 30 Minutes (Boil)
1.7 g/L Simcoe (12.2% Alpha) @ 15 Minutes (Boil)
1.1 g/L Simcoe (12.2% Alpha) @ 0 Minutes (Boil) [DRY]

0.7 g/L Whirlfloc Tablet @ 15 Minutes (Boil)

Single step Infusion at 66°C for 60 Minutes. Boil for 60 Minutes

Fermented at 20°C with Safale US-05 (active starter)

Process
Few rookie questions here:

1) I've done a few stove top experiments and with my 19L Big W pot and dodgy stove, it's hard to maintain a constant temp. I have a large techni ice esky that will fit the 19L pot, so I was thinking of going along the lines of Bribie G's Pimping a Coopers Kit post and lining my pot with a BIAB bag, adding 70C water and grain, then putting the lid on and placing the pot in the esky in a 66C water bath for 60 mins. Is this going to work?

2) To mash 2kgs of grain, is 5L enough water?

3) I was planning on sparging with another few litres of 66C water. Is this right?

4) After the mash, should I take a gravity reading to determine if my liquor is at 1.040 for the hop boil?

5) Is there anything else obvious that I'm missing?

Sorry for the basic beginner questions. Feedback really appreciated.

Cheers!!

 

[verysupple]

As I've yet to crack a good IPA recipe I won't comment on that. The process I'm much more familiar with...


1) Does your BigW pot fit in your oven? If so you can use that to help maintain the mash temp. I use a meat thermometer on top of the pot to monitor the oven temp. I find that a couple of degrees above the desired temp is about right to maintain the mash temp (assuming you hit your mash in temps, otherwise adjust prior to putting in the oven).

2) 5 L for 2 kg of grain is a pretty thick mash. It shouldn't be a problem if you're not applying direct heat (e.g. a direct fired step mash).

3) Sparging is up to you. It might help efficiency with the thick mash you're proposing, but be aware that you'll have to boil that extra volume. If you can't boil the extra amount then I wouldn't bother.

4) Taking a gravity reading is good for record keeping and understanding your system. That said, it won't be that important for you obtaining a reasonable boil gravity as your grain bill should give you plenty of sugars to not worry about astringency etc.

5) I can't think of anything obvious, but I sometimes overlook the basics so maybe wait for some other replies.

Happy brewing!

 

[Blind Dog]

1. Yes,if your esky can maintain temp. Not sure about the rye, wheat or carapils though. You need to make sure they have enough diastic power to convert themselves (ie extract the sugars). How are you milling / crushing the grains? Rye and wheat can be difficult; they're also sticky

2. As verysupple

3. Traditional storage would be with 76C ish water, but not higher. Lower is ok, it just seems to extract a little less

4. If you do remember to adjust for temp

5. If you've got the time to do a mini mash, I'd just bite the bullet and do a BIAB AG brew. Other than the bag (Swiss voile from spotlight; put it in your pot, smooth out the sides and cut it to give a decent overhang that won't burn; seal the edges with a gentle heat source (stove top lighter when I did it)) you're all set

 

[verysupple]

<snip>

5. If you've got the time to do a mini mash, I'd just bite the bullet and do a BIAB AG brew. Other than the bag (Swiss voile from spotlight; put it in your pot, smooth out the sides and cut it to give a decent overhang that won't burn; seal the edges with a gentle heat source (stove top lighter when I did it)) you're all set

I agree with Blind Dog if you're confident in what you're doing.

If not, I'd still go with a partial mash where ~50 % of your fermentables come from extract. I recommend this because you probably won't get very good efficiency on your first attempt so the extract works as a good backup. Also, partial mashes can taste great if the recipe is decent so there's no real compromise on flavour.

 

[shacked]

As I've yet to crack a good IPA recipe I won't comment on that. The process I'm much more familiar with...


1) Does your BigW pot fit in your oven? If so you can use that to help maintain the mash temp. I use a meat thermometer on top of the pot to monitor the oven temp. I find that a couple of degrees above the desired temp is about right to maintain the mash temp (assuming you hit your mash in temps, otherwise adjust prior to putting in the oven).

2) 5 L for 2 kg of grain is a pretty thick mash. It shouldn't be a problem if you're not applying direct heat (e.g. a direct fired step mash).

Thanks for the input mate.

The pot doesn't fit in the oven, hence the esky idea.

I can fit loads more water into the 19L pot. What's a good ratio to work to?

 

[shacked]

1. Yes,if your esky can maintain temp. Not sure about the rye, wheat or carapils though. You need to make sure they have enough diastic power to convert themselves (ie extract the sugars). How are you milling / crushing the grains? Rye and wheat can be difficult; they're also sticky

2. As verysupple

3. Traditional storage would be with 76C ish water, but not higher. Lower is ok, it just seems to extract a little less

4. If you do remember to adjust for temp

5. If you've got the time to do a mini mash, I'd just bite the bullet and do a BIAB AG brew. Other than the bag (Swiss voile from spotlight; put it in your pot, smooth out the sides and cut it to give a decent overhang that won't burn; seal the edges with a gentle heat source (stove top lighter when I did it)) you're all set

Cheers Blind Dog!

1) I was going to get the LHBS to sort out the milling/crushing to an appropriate spec. The idea behind the rye was driven by me liking Rye IPAs and not being able to make them with just extracts and steeping specialty grains! Should I go for something more straight forward for my first go?

3) Any guidance on volume?

5) I'm tempted but I still have a fair bit of extract in the cupboard!! If I do a 23L batch, do I need to do a full boil or can I get away with doing a 12-14L boil (in my 19L pot) and subsequently topping up with additional water before pitching?

Thanks for the feedback! Really appreciated.

 

[ootsby]

I've got a similar lack of equipment and I tend to work from a perspective of using as much grain as possible. I do BIAB with a 15L pot and usually mash around 3kg of grain in 10L of water. The pot goes in my oven to maintain temp. I normally mash for 90 minutes and give it a stir at around 60.

After the initial drain and squeeze the bag goes in my fermenter where I'll add 3L or so of 75C sparge water. While that's sitting I start heating the pot wort to a boil. By the time it's near boiling I can drain and squeeze the bag again and pour the resulting wort into the pot. Then the bag gets a final 2-3L of sparge water and that wort just goes in when there's room in the pot during the boil.

Using this method I get very high efficiency, maintain a 13L-ish boil volume and only need a single can of LME to hit 1.050+ OG at 23L when topped up with water.