15 replies to this topic

[Big Nake]

I have seen this mentioned on various sites and I just took this off of Kai's site. It's a relatively basic step infusion mash (145/158-ish) that is supposed to help with attenuation, head stability and mouthfeel. I'm a sucker for any German process that may improve the quality of my beers. Kai writes...Another stepped infusion mash that I want to highlight here is the Hochkurz mash. There is also a decoction version of this mash which is described in the Decoction Mashing article. Here we want to focus on the infusion version of this mash schedule. Hochkurz is the combination of 2 German words: hoch means high and kurz means short. It refers to the fact that the mash doughs in at a high temperature (above protein rest temperatures) and is fairly short (less than 2 hours). The Hochkurz mash has become the standard mashing schedule for beers brewed in Germany. Especially large breweries like it because it doesn’t require decoction and can be done in less than 2 hours which fits well with their desire to be able to mash a new batch every 2 hours. It uses 2 different sacharification rests; one for each group of amylase enzymes. A low temperature rest favors the beta amylase and sets the fermentbility of the wort. A high temperature rest favors the alpha amylase and completes the starch conversion. The temperature steps necessary for this mash schedule can be achieved through infusions of boiling water or direct heat. If boiling water will be used the mash should be doughed in with a water to grist ratio of about 2.5 – 3 l/kg (1.25 – 1.5 qt/lb). Don’t be afraid of thinning out the mash through the hot water infusions. It will become easier to handle and enzymes and gelatinization also work better in a thinner mash. If direct heat is used aim for a mash thickness of 3.5 – 4.5 l/kg (1.75 – 2.25 qt/lb). This is the mash thickness that is commonly used in Germany and it makes stirring the mash during the heating phases much easier. You should also aim for a dough-in temperature that is slightly lower than the first rest temperature since it is much easier ho heat the mash than to cool it in case the first rest temperature is not hit after dough-in. The first rest (maltose rest) should be held at or around 63C (145F) and it’s length is used to control the fermentability of the wort. A good starting point for its duration is 30 min. Longer for more fermentable wort and shorter for less fermentable wort. If even higher fermentability is desired an intermediate rest at 65C (150F) can be added. Due to its large volume the mash temperature should not drop much during that rest but you may wrap the pot into blankets to stabilize the mash temp even more. The dextrinization rest at 70-72C (158-172F) needs to be held until the mash is iodine negative but may be extended to 45-60 min. Many authors contribute head retention and mouthfeel benefits to extending this rest. Finally the mash may be raised to mash out temp and subsequently lautered. Anyone use this either sparingly or more often and have any insight to how well it works or what the benefits seem to be?

[denny]

I've done it several times and I'd be hard pressed to say it made a difference. But I haven't gotten around to doing a blind triangle tasting on beers made with it.

[Big Nake]

I've heard people say that the lower-temp mash ensures good fermentability and attenuation and then the higher-temp mash gives the beer some maltiness & mouthfeel. I'm intrigued by this because if there is a space between "single-infusion" and "decoction" that adds some depth to a beer, I'm all for it. The various things you can do during a mash always interest me but I always go back to the fact that many people say that these are things that brewers did over 100 years ago because they had to & because of heavily modified malts that are available today, we (as homebrewers) do not have to do these things.

[MtnBrewer]

I've heard people say that the lower-temp mash ensures good fermentability and attenuation and then the higher-temp mash gives the beer some maltiness & mouthfeel.

Mouthfeel, yes. Maltiness, no. You should get some body and mouthfeel from the higher rest but not maltiness.

I always go back to the fact that many people say that these are things that brewers did over 100 years ago because they had to & because of heavily modified malts that are available today, we (as homebrewers) do not have to do these things.

Exactly. Remember that mashing is just a continuation of the malting process. If malts are malted differently today than they were in the past, then they also require a different mash than what was once necessary.I've tried this mash (although I didn't know it had a name) and I'd have to agree with Denny. It would be hard to find a difference without a blind test. The first rest should convert the hell out of straight starch chains. The only dextrins left would be branched starches that the beta amylase couldn't get at. The higher rest then would break those chains and also fragment any long straight-chain dextrins left over from the first rest into randomly-sized straight chains. If you do a single infusion, you have both processes going on at once (at different rates) so when the branched dextrins get cleaved, the beta amylase can take those straight chains and turn them into maltose.

[Big Nake]

I'm not sure that I would make two batches of the same beer, one with a single-infusion and one with the Hochkurz mash but I could see that being a decent experiment. I like they way he says that adding boiling water can help raise the mash temp and not to worry about thinning out the mash. I do not have a direct-fired method for raising the mash temp so boiling water is the way I would do it. That said, it seems pretty easy to try and the extra time would be minimal. I was thinking of making something that has 55% pilsner malt, about 38% vienna, 5% CaraFoam and about 3% Acid malt, all Tettnanger hops (1½ oz for FWH and another ounce at 5 minutes), Wyeast 2001 Urquell and all distilled water with additions. I could do one with a Hochkurz and another single-infusion at 150-151° and then compare the two... eventually.

[MtnBrewer]

I disagree with the "don't worry about thinning out the mash" part. If you mash in at a high water/grist ratio (2-ish qt./lb.), then it's going to take an additional 2+ gallons to reach the dextrinization rest. That leaves you less than 2 gallons to sparge with and I think that's going to kill your efficiency.

[shaggaroo]

Isn't that why he says 1.25 - 1.5 qts/lb to start?

[MtnBrewer]

Isn't that why he says 1.25 - 1.5 qts/lb to start?

Yeah, I saw 1.75 - 2.25 but that was for direct heat.

[shaggaroo]

Yeah, I saw 1.75 - 2.25 but that was for direct heat.

No worries... I may have to try this, just to see how it goes.

[Big Nake]

I usually mash with less water anyway so I would go with a thicker mash for the first mash and then add boiling water until I reached the second mash temp. I made a German Pilsner last month where the mash called for 4.50 gallons of water for 10lbs of grain which is 1.8 qts/lb which is quite a bit higher than I would normally go. I read someplace that Germans use a thinner mash consistency. I don't know but again, seems easy enough to try it out to see what the results might be. I will post back if I try it.

[MtnBrewer]

I usually mash with less water anyway so I would go with a thicker mash for the first mash and then add boiling water until I reached the second mash temp. I made a German Pilsner last month where the mash called for 4.50 gallons of water for 10lbs of grain which is 1.8 qts/lb which is quite a bit higher than I would normally go. I read someplace that Germans use a thinner mash consistency. I don't know but again, seems easy enough to try it out to see what the results might be. I will post back if I try it.

I know traditional pilsners (with a decoction) are brewed with a thin mash. I think this is so the mash will maintain its heat and not lose temperature when a big chunk of the mash is removed for the decoction. But yeah, if you're trying to do a step infusion, start out as stiff as you can.

[Brauer]

This is the mash schedule I usually follow, though I vary the first step between 145°F and 150°F depending on the beer I want to make (148°F is typical, for me). I calculate it to hit around 2-2.25 qts/# (though I don't worry about hitting a specific thickness, very much) after the infusion. My experience has been that these beers finish with less residual sweetness, but still maintain some body, a character I always had trouble hitting with single infusion, which seems to leave me with too sweet a finish for my taste. I've never done the experiment to really test this, but I've been very happy with my beers since I switched to this mash schedule. I think it works similarly to a 90' mash, "setting the fermentability", or whatever that phrase is.It doesn't add any time to my brew day, because it occurs in the middle of the mash. You do have to go through the effort of heating up the step water, but I skip the mashout, so it all comes out in the wash. As to the thin mash, it helps with conversion efficiency, as does the step, so you may see a gain in overall efficiency. I get very high efficiency with this technique. I don't think there's anything particularly magical about this schedule, and any flavor differences are pretty subtle, but I like the results and it's a virtually effortless change from a single infusion with a mashout.

[Big Nake]

The only other question is where to put that second (dextrinization) rest. I assume there is a typo on that page of Kai's because it says 70-72c (158-172f) which I know cannot be right. So if I went with 145°f for 30 minutes, I should go to WHERE for the last 60 minutes? Around 160°? Cheers guys.

[Brauer]

Actually, 70-72°C is 158-162°F, which is a good range for the Alpha Amylase rest, so 160°F is fine.

[weave]

Wasn't this mash sequence made up by some guy named Mike? You know, Mike Hochkurz. Awww c'mon. Someone had to do it. I couldn't read the title of the thread one more time without doing something about it.

[Big Nake]

Wasn't this mash sequence made up by some guy named Mike? You know, Mike Hochkurz. Awww c'mon. Someone had to do it. I couldn't read the title of the thread one more time without doing something about it.

I'm surprised it took THIS long.