An alternative way of doing BIAB?

[kzlc]

Hi there,

I'm a newbie both in this forum and brewing.

I live in Turkey and we don't have any homebrew stores here. So, I have to start with all-grain and even with malting. It's quite discouraging but, anyway, I have to deal with it.

The main problem I face with is the very low efficiency of the mash. The O.G. I get is around 1020 to 1025, If I don't boost it with adjuncts. I am tended to put the part of blame on the quality of barley (which is also a usual concern of large-scale brewers in Turkey) but I still have some hope that I can better results by doing a more efficient mash.

This is my question: To my knowledge, each enzyme has a temperature range. The point of doing decoction mash is to catch the correct range for every enzyme (right?). So, if we're doing BIAB, instead of trying to hold the temperature constant, why don't we start with a relatively lower temperature (as low as 50 C) and increase it up to 71 C in one hour, until the enzymes are deactivated?

My question may sound naive, but I guess that being a beginner is a good excuse.

Thanks

 

[MalFet]

Decoctions have more complicated impacts than that. What you're describing is basically a step-mash. It works fine, though it would probably be worth the effort to figure out what exactly is going on with your barley to make sure you're hitting the right targets. I suspect your malt is undermodified and possibly high in protein. There are different rest temperatures that will help with those situations.

Check out Kaiser's website (braukaiser.com) for some great background to the mashing process. Palmer's book (1st edition - howtobrew.com) has some good info too, though I find his metaphors extremely hard to follow. If you can get books shipped in form overseas, Greg Noonan's book "New Brewing Lager Beer" is great.

 

[TopherM]

You could certainly do a step mash, just like in traditional AG brewing, but the whole point of BIAB is maximizing the brewday with the simplest methods possible to still produce good beers, so a step mash BIAB kinda goes against that spirit.

That said, there are lots of much easier methods to increase efficiency without doing a step mash.

1) First and foremost for BIAB, you can grind your grain pretty much as fine as you want. More surface area exposed to the enzymes = higher efficiency. You don't really want your grain to be flour, but really just a micron or two above the size of the holes in your bag would be ideal, so you want a pretty fine crush. I typically crush just a bit lower than my mill's factory preset, but I always send the grain through twice. You can seriously expect a very big jump in efficiency just from a fine crush.

2) If crush isn't your problem, another easy way to get your efficiency up is to simply use more grain. If you are getting 1.025 OGs that are supposed to be more like 1.05 OGs, then with ALL OTHER FACTORS BEING EQUAL, you could scale your recipe with 100% more grain and get up to to the 1.05 OG at your current efficiency levels. Not ideal, but it would work perfectly.

3) I find that a mashout adds about 3-5% to my efficiency rate on my system. After your mash, ramp up your temps from the 146-156F mash temps to 170F mashout temp over a 10 minute period, being sure to stir the mash pretty much the whole 10 minutes. This both stops enzyme activity and flushes extra sugars from the grains.

4) SQUEEZE THE CRAP OUT OF THE BAG!! The absolute most concentrated wort stays saturated in the grain bag after you pull it. The more you can squeeze out of the grains into your wort, the more you are upping your efficiency. If you aren't squeezing the bag, you will gain some serious gravity points just by getting 40-60% of the wort out of the grains after your mashout. Get some brewers gloves or some other gloves that will insulate your hands from the heat of the grains so you can really get into the squeeze.

One, all, or a combination of these things will drastically up your efficiency and OG!

 

[kzlc]

Many thanks for the replies.
I'll definitely try your suggestions.

 

[GoldenShowerGladiator]

doesn't squeezing the bag release tannins?

 

[MalFet]

doesn't squeezing the bag release tannins?

In a word, nope.

 

[JeepDiver]

If you have a way to keep the bag off the bottom of the kettle, then step mashes work perfectly fine with BIAB, and with undermodified grain it may give you a few more points.

 

[kingwood-kid]

You malt your own grain? Wow. Assuming that the problem is a lack of enzymes, you could just order some amylase powder and add a little to the mash. I don't know what it costs to ship to Turkey, but amylase costs next to nothing.

 

[kzlc]

You malt your own grain? Wow. Assuming that the problem is a lack of enzymes, you could just order some amylase powder and add a little to the mash. I don't know what it costs to ship to Turkey, but amylase costs next to nothing.

Yes, I'm not happy with that but I have to malt.
I also made some thinking about using alpha-amylase. It's also accessible in Turkey. But in his book, Papazian doesn't recommend that. He says that the use of exogenous enzymes is not very controllable. I also think that there should be something undesired in the use of exogenous amylase. Otherwise the whole process of malting would become obsolete, right?

 

[kingwood-kid]

From Brew Your Own Magazine:
The corn or rice used in American Pilsners is not malted, so it contributes no starch-degrading enzymes to the mash. The corn or rice starch is degraded by amylase enzymes from the malt or, in the case of very high adjunct rates — as when making a malt liquor — by enzyme preparations added to the mash.


Adding alpha-amylase alone will skew its ratio with beta-amylase. This will favor the production of dextrins over fermentable sugars. You would have to mash lower & longer (or use some simple sugars) to make up for it.