Bottle fermentation over - time for cooling

After 48 hours at 6°C

The beer has now been bottle fermenting (what you'd call Nachgärung in german) for a week at about 22°C (in my office). In case you missed the previous post, the idea of the bottle fermentation is that the beer builds up CO2 in a closed environment. The CO2 can't escape (it's in a bottle), so the beer gets fizzy. And how do you create the CO2? Well, when yeast is fed with sugar it breaks the sugar down into alcohol and CO2 (in about equal parts). So when the main fermentation (in the keg) is over, you basically have flat beer (as the CO2 escapes). When bottling each bottle gets a little sugar and the remaining yeast (in suspension) in the beer takes care of the rest. The aim is that you can decide beforehand how fizzy the beer should be (Weizenbier is typically fizzier than, say Kellerbier) and going on the temperature you can figure out how much sugar you need per litre of beer. More experienced brewers don't use sugar at all - they tap off Jungbier before it is finished fermenting (i.e. there is still sugar in it which can be coverted to alcohol and CO2) and keep it separately, in the fridge. In german it is called the Speise. Before bottling, the Jungbier is piped onto the Speise and mixed in. This is actually how it is supposed to be done. The method with sugar is a bit of a workaround (incidentally, the new Reinheitsgebot actually allows this for top fermenting beers). There is also a method called Grünschlauchen, which means bottling before the beer is finished fermenting in the keg. Grünschlauchen means you really have to keep an eye on the rest sugar though - and you run the risk of either flat beer or (worse) bottle bombs (where there is too much sugar left in the Jungbier).

My beer is now in the fridge since yesterday, at about 6°C. One bottle was in since the day before, for testing. I tried some of it last night (the glass in the picture is 100ml - perfect for testing). It still has a bit of a wild taste and definitely needs a couple of weeks in the cold. I was also quite surprised to see how much CO2 it had developed. I'm not sure that a Klosterbier should be fizzy - it seems like a beer that should be drunk out of a Steinkrug and shouldn't have that much gas. It was good to see that between yesterday and today the foam got a bit more stable. It's too soon yet to decide if the foam didn't work out (I'd need to check the log of the mashing to see why).

Other than that, there is now nothing to do except wait. From the 500ml bottle I kept as a sampler, I'll try 100ml every night. Next weekend, the beer should have settled down somewhat, though I expect it will be at least two weeks before it will be properly 'drinkable'.

Bottled and ready

Yesterday, we bottled the beer that had been fermenting since the previous Sunday. The rule of thumb to adhere to before bottling is that the main fermentation should be over as evidenced by no activity in the fermentation keg for at least three days. 'Activity' could be seen as CO2 escape (the blubbering) or, to be more exact, the rest sugar level. To determine the rest sugar in the beer you can use either a hygrometer (the archimedes principle) or you can use a refractometer. I bought a refractometer because it means you lose less beer. If you use a hygrometer you have to tap off 200ml of beer every time (a couple of times a day). With a refractometer you only need a drop or two. The refractometer measures how refraction of light as it passes from one material into another. It is measured in Brix (after the guy who invented it). Since last Wednesday my rest sugar level was 7.2 Brix (which works out at about 2,4°P after a rather complicated mathematical excursion which eliminates the effect that the alcohol in the beer has on the refraction).

So, there you have it - about 20l of home made beer "Klosterbier". It turned out to be a darker kind of beer (probably because I dumped the Farbmalz in right at the beginning rather than 10 minutes before the end of the mashing) - not full a 'dunkles' but certainly in that direction. It will also be Naturtrüb (cloudy) - I don't think it is possible to get a really clear Klosterbier. Now, the beer ferments again at 20°C in the bottles, for about a week. This "recreates" the CO2 in the beer (I want about 5g/l). Then the beer goes into the fridge at as close to 0°C as possible, to diffuse the CO2 into liquid (the colder, the better). After at least a week, (the longer the better), the beer can be moved into a normal fridge, somewhere around 6-8°C.

Spindelprobe after one day

Yesterday, after consultation with one of the colleagues at work who has been brewing beer for a couple of years, I decided to stretch the beer. You might have seen from the previous post that I had a Stammwürze of about 15,6° Plato before the yeast went in. That is a bit too high. The recipe said that it should be about 13° Plato (which tends to end up as a beer with about 5,2% ABV). If I didn't intervene I'd end up with about 19l of a strong Vollbier - almost Bockbier. There's nothing bad to be said about a good Bockbier, but 19l of it is too much. I wanted a more standard beer - around 5% or 5,2% ABV and nicely rounded. Not 8% ABV and too sweet.

So, I decided to use the high gravity procedure - by coincidence really. High gravity means you deliberately brew to a high Stammwürze and then stretch the amount by adding cooked water. That way, you can expand how many litres you get, depending on your storage. In my case, my fermentation keg is 60l and my filling buckets hold 34l. This means I could theoretically fill over 30l of beer with no problem. My limiting factor is my Silvercrest cooker. That can only hold about 26l - less if you want to cook at 100°C. For the first Sud it was actually the SIlvercrest that limited the volume. I could have added at least another litre of wort. Anyhow, by coincidence I'll be using the high gravity method - not to increase the return of finished beer, but to reduce the ABV of the beer. Essentially, it is diluting. However, by diluting while the yeast is still active, I'll be changing the fermentation process itself, rather than just diluting the Jungbier when it's finished.

The Spindelprobe of Jungbier had 7,2% leftover sugar, meaning the fermentation is nowhere near finished. Right now it is still blubbering away - though the C02 concentration is certainly nowhere near where it was yesterday (expected). The beer tastes a bit wild - the underlying taste is good, but it is too fizzy (expected) and the flavour isn't rounded yet. The hops/bitterness was good, so I'm hoping the 2l of water won't take the edge off that. I'll tap another Schnappsglass this evening to see how it's coming along.

First Sud is in the pot

19l of cooked wort

So, finally the first Sud is in the pot. It's about 19l and it is now fermenting happily (I hope) at 21°C in the guest room. I started yesterday, by checking the equipment, sterilising and generally getting everything ready. This morning at 07:00 I heated 13,5l of water to 38°C and then added the malt mix (Münchner and Wiener malt). After heating up to 48°C for a twenty minute protein rest, I added the colour malt. It is supposed to be added only 10 minutes before the end of mashing, but I figured I'd dump it in early to get more colour into the beer. After the protein rest, I heated to 64°C and kept it there for a good forty minutes. This is the maltose rest, where fermentable sugar is released into the wort. Then, up to 72°C for another thirty minute rest. This is where the non-fermentable sugar is released. After a quick check with iodine, to make sure there was no starch remaining in the mash, I heated up to 78°C and then spooned the mash into the Läuterbottich.

Läutern

The läutern was a bit of a chore. The idea is to separate the wort from the mash - i.e. what you want is the liquid. What happens is that the solid skins of the barley/wheat form a filtration layer at the bottom of the bucket. The liquid filters through and is decanted out through a tight spiral called a Läuterhexe. The liquid is then gathered and put back into the Einkocher for cooking hops. While läutern, you use all the mash and then add (in this case) 18l more water (the Nachguss) which is heated to 78°C before being added. I'm going to see about getting a second Einkocher to keep the 18l ready - constantly heating 1l amounts in a kettle made the whole thing a bit tedious.

In the end I filled the Einkocher to max (probably about 27l). The wort was heated up to boiling and then the hops got added (in a cloth hops bag). About 30g of Hallertauer Perle came in when the wort boiled (and stayed in till the end). This is for the bitterness. Another 14g came in about 12 minutes before the end of the cooking. This is for the aroma. Once I was finished boiling, I whirlpooled the boiling wort and piped it from the Einkocher into the fermentation keg - via another filter (to ensure none of the solids (hops) got into the fermentation keg). When finished I had about 19l. The rest evaporated during cooking.

Cooling the wort to 22°C

Shortly before the end of cooking I got the yeast ready. I added boiling (sterilised) water to a jam jar and then cooled it down to 26°C (the ideal temperature for 'starting' the yeast). After about half an hour the dry yeast powder had formed a kind of a frothy cream in the jar. Once the wort was cooled down to 22°C using the spiral cooler, I added the yeast mixture, sealed the fermentation keg (except for the CO2 escape) and carried the keg up to the guest room. Then, I cleaned all the equipment and called it a day. Currently, I'm still waiting to see when the yeast 'takes' and starts creating 50% alcohol and 50% CO2. Below are some of the other photos.

Heating and stirring the mash

The motor did it's work just fine

The iodine test shows there is still starch in the mash

Now the iodine test shows all the starch has been converted to sugar

Transporting the mash into the Läuterbottich

Clear 'Würze' after läutern

Hops added to the boiling wort

This was a much nicer ball after the whirlpool but broke up while piping

Stammwürze (a bit higher than expected)

Rührwerk in action

The propeller arrives!

Today I picked up the stainless steel propeller from Grasser and fit it to the motor. It fits perfectly! It hangs down to about 5mm above the temperature sensor of the Silvercrest - I was a bit wary when measuring, that the rod would be too long and might touch the sensor. It was perfectly built, though. There is about 10mm space between the outer edge of the blades and the Silvercrest wall. This should be perfect. One thing I have to check out is whether the motor is bi-directional. If it only goes in one direction, a problem might arise that the propeller rod would screw itself out of the M8 socket. If I can make the motor go the other way, this won't be a problem as the rod would tighten itself.

Yesterday, I faxed the brew registration to the Hauptzollamt in Landshut - 23l of 13°P wort. So everything is set up and ready for Sunday.

Ready to brew next Sunday

The last order from Hopfen und Mehr was delivered by GLS today. I ordered the basic Klosterbier malt kit, a beer paddle, 5m of silicon tubing, a plastic tap for the second bucket, some bags for boiling hops and an emergency spare yeast packet. I'm hoping I won't need that spare packet of yeast.

If successful, the Klosterbier should looks something like the picture on the left (which is part of the picture documentation here). I'd rather a clearer beer, but with the Safale yeast, I don't think that will be possible. Even on the back of the packet it says "high sedementation". I'm thinking I might whirlpool in the Silvercrest after cooking and then - instead of lifting straight into the fermentation keg - I could lift into an empty bucket and whirlpool a second time. Then, lift into the fermentation keg via a Sputnik filter. When the fermentation is finished, I could lift into a bucket (to avoid disturbing the sediment at the bottom) and then fill the bottles from that. Even with that, I think the Safale S-04 will have so much in suspension that it is pretty much a waste of time. The naturtrüb (cloudy) beer isn't too bad though. The main thing is the taste. This has a Stammwürze of 13°P - I'd say it will work out at about 5,3% ABV.

Once I get the Klosterbier done, I want to try a Samba Pale Ale. This is a bastard form of India Pale Ale (IPA). I want it to have a relatively low Stammwürze (10°P if possible) and corresponding relatively low ABV (3 - 4%ABV). The main advantage of the Samba Pale Ale is that from brewing to drinking it only takes four weeks.

Dry run

Heating to 100°C

I'm hoping to get the first Sud done next Saturday or Sunday. I still have to register it at the Customs Office and they were supposed to send me the information on how to do it by post today. Hopefully it'll be there on Monday and hopefully I'll be able to do the registration electronically. As well as that, the package from Hopfen und Mehr is due to arrive on Monday. My malt is in the package as well as a silicon tube (for lifting the beer) and another tap for the second bucket (the bottle filler fits directly on to this tap). It's going to be a Klosterbier - a top fermenting beer with a small bit of a red/dark colour and (probably) a deal of malt aftertaste. We'll see.

To make sure there are no nasty surprises on Saturday, I did a dry run today. Before I started, I managed to get my mixer motor working properly. I don't think that Grasser will have my mixer ready by next weekend so I'll probably have to stir the mash by hand. What I wanted to test were (a) whether the Einkocher (the Silvercrest) would manage to boil the water properly, (b) whether the cooler works properly and (c) whether the tap on the Läuterbottich is (still) leaking. I started off with the Einkocher, which - you may remember - is now insulated with a double layer of foam mat. I heated about 18l of water from 12°C to 98°C in about forty minutes. The good thing was that it did boil the water this time (the insulation made the difference). It wasn't a really 'violent' boiling, but enough to make sure the alpha acids are dissipated into the Würze.

Cooling the water

As soon as the water was boiling, it was time to cool it down to about 24°C as soon as possible. The reason for this is that the Würze (which is basically sugar water) becomes very attractive to all kinds of bacteria - especially once it gets below 40°C. Once the yeast gets into the Würze and gets active, the danger from external bacteria is not as high, because the yeast cells are aggresive and don't leave much room to other bacteria. In order to get the temperature down fast, I got a beer cooler. This is basically a long spiral of stainless steel pipe. I connected this to the tap on one side and the other side went into the drain. I put the spiral into the Einkocher (the water was about 95°C) and turned the tap on. I was amazed at how fast the temperature dropped. It went from 95°C to 25°C in nine minutes! This was much better than I expected - I think the spiral is meant for a bigger pot, but it fit perfectly into the Silvercrest.

Once the temperature was at 25°C, I decided to drain the Einkocher into the Läuterbottich to test the tap. You might remember that the tap was leaking - not much, but enough. I don't want to lose any of the Würze to leaks. All I did was tighten the the whole contraption. With the 18l of water in the Läuterbottich, it didn't leak - I tested for about ten minutes. I emptied the water into the drain, dried the Silvercrest and declared the dry run a success. Which means, come Saturday, I should be ready to brew.