Category Archives: Homebrew

Brewing split batch sour beers (Sour Blend and Lachancea thermotolerans)

I’m not the biggest fan of sour beer, but I am still very interested in brewing with non-conventional microbes. I brewed a batch of sour beer using Wyeast’s Lambic Blend and some bottle dregs around 3.5 years ago. It turned out surprisingly nice, and it got complements from many of my friends who love sour beer. Together with one of these friends, I brewed up a fresh 30L batch of wort (a couple of weeks ago), which I split into two fermenters. These two sub-batches were pitched with two different cultures: The Yeast Bay’s House Sour Blend, which contains a mixture of several different yeasts and bacteria, and a pure culture of a strain of Lachancea thermotolerans, which we’ve (our lab at VTT) isolated from an oak tree here in Finland.


Lachancea thermotolerans is a very interesting yeast, because of its ability to produce lactic acid. From a brewing perspective, this means it can applied e.g. to sour beer production. This is particularly interesting, because it allows for the production of sour beer without the cross-contamination risks associated with the use of lactic acid bacteria. Lachancea thermotolerans has recently gathered some interest in the brewing science community as well, as last year there were some published studies and conference presentations on the topic.

We haven’t really characterized our isolate of L. thermotolerans yet, so I thought I’d try it out in a homebrew batch. The pre-culture was smelling promising, with a strong fruity aroma combined with a distinct lactic tartness. As I wasn’t sure how the isolate would handle high osmotic stress or high ethanol concentrations, we decide to play it safe by brewing a relatively low-gravity wort. Using a 50/50 blend of pale ale malt and wheat malt, we aimed for a specific gravity of 1.050. As my brew kettle doesn’t fit 30 liters of wort, we decided to dilute the ‘Sour Blend’ portion of the wort with water. Hence we ended up with 15 liters of 1.049 wort for the L. thermotolerans portion, and 15 liters of 1.037 wort for the ‘Sour Blend’ portion.

For hops, we went with some old Saaz hops from 2010 I found in the freezer. We only aimed for a couple of IBUs. The L. thermotolerans portion got an additional handful of Nelson Sauvin hops I also found in the freezer (from 2013, so it had definitely lost some punch) added to it after flameout. We were hoping this would complement the fruity aroma that the yeast seems to produce and add a slight bit of extra bitterness.

After 2 weeks of fermentation (starting from around 19C, rising to around 23C), I transferred the L. thermotolerans portion to a keg for carbonation. The gravity had dropped to 1.011 (for an attenuation of around 78%), suggesting the yeast is capable of using maltotriose. This is quite an important result, as maltotriose is typically the second most abundant sugar in wort. The pH of the beer had dropped to 3.48 and the beer was definitely tasting sour, suggesting that a considerable amount of lactic acid had been produced by the yeast during fermentation.

Overall I’m very happy with the flavour and the aroma. The aroma is very fruity, with hints of stonefruit and tropical fruits. In the flavor there is a nice balance between the fruity and the sour notes. The flavour is also very clean, and with this I mean that there are no strange or off-putting off-flavours. This L. thermotolerans isolate also doesn’t produce any phenolic off-flavours (POF-).

L. thermotolerans is definitely a promising candidate for sour beer production, and I’m sure we will see more acid-producing yeasts pop up in the near future.


WLP099 and maltotriose

I posted a similar post in the ‘Milk The Funk’ Facebook group recently, and thought I’d copy it over to the blog as well. This post will be about White Labs’ WLP099, which I’ve been using recently for some fermentations. What are people’s experiences with it? Reading around on various homebrew forums etc. you get the impression that this yeast is a monster that will eat through everything you throw at it. Some people are even reporting that it ferments worts down to specific gravities closer to 1.000 (just do a search for “WLP099” on Homebrewtalk). This is very much in contrast to my own experiences with. Using single cell isolates of it in test fermentations, I’ve noticed that it is unable to use maltotriose, and usually ends up with attenuations of around 70% in wort. The only other similar experience I found after googling around was (apparently with input from Mr. White himself):

This of course very much goes against the fact that this yeast could ‘super-attenuate’ plain wort (which would at least require the use of maltotriose, and possibly even longer sugars). So I guess these high attenuations can only be achieved in worts supplemented with simple sugars? Another possibility is that the yeast is actually a blend (either intentional or unintentional; more on this later below).

I did some more digging, and came across this recent study by Borneman et al.:

In it they’ve sequenced a set of mostly wine strains, but they’ve included some White Labs strains as well: one of which is WLP099. Interestingly, it was found to belong to the wine yeast clade. So the fact that it actually seems to be a wine strain, would explain the lack of maltotriose use (and would fit with it having good ethanol tolerance). This paper unfortunately doesn’t go into physiology.

Another study that probably included this strain and does go into physiology is of course the recent Gallone et al. paper:

The strain names are unfortunately encoded, but I did some more digging. Going by the fact that WLP099 is POF-, I looked at the SNPs in the sequences of its PAD1 and FDC1 genes using the reads from the Borneman et al. paper:

Cross-referencing with all the sequences from the Gallone et al. paper, I was able to find only 7 strains containing the same SNPs (Beer024, Beer033, Beer088, Spirits002, Wine001, Wine009 and Wine013); all seven of which belong to the wine clade! Of these strains one, Beer033, seems to have a familiar origin and description (from Table S1): England, Beer (Strong Ale). I think we’ve found WLP099. Anyways, looking at Figure 3 and Table S5 we see that this strain doesn’t use maltotriose! Five of the other six strains which it could be also don’t use maltotriose. Beer088 is the only strain with the same SNPs which uses maltotriose, but its origin is Germany so it’s unlikely that strain would be WLP099.

So, looking at the different independent evidence (my own ferments, the forum post with the apparent input from Chris White, and the Borneman et al. and Gallone et al. papers) it looks like WLP099 is actually a wine strain and I think we can say for sure that it doesn’t use maltotriose and thus won’t super-attenuate in wort, unless it has been supplemented with simple sugars. So regarding finishing off high-gravity ferments with this yeast, it looks like it is only useful for worts to which you add sugar. In worts made only from malt, WLP099 would likely have little to no effect when adding it as a secondary yeast (i.e. when all of the monosaccharides and most of the maltose has been consumed).

So how are peopling still getting 80+% attentuations with WLP099 as the only yeast in all-malt worts? There was some speculation in the ‘Milk The Funk’ Facebook group, that WLP099 might actually (either intentionally or unintentionally) contain two yeast strains (two independent observations were given). If the other yeast strain was a dextrin-degrading one, such as S. cerevisiae var. diastaticus, it could explain how people are seeing ‘super-attenuation’ with WLP099. These strains produce extracellular glucoamylase enzymes which break down dextrin to glucose molecules, which WLP099 could then easily ferment. But this is of course only speculation!

Tasting Impressions: J&L Wedding Dunkel and Pale Ale

As I mentioned in my previous blog post, I brewed two batches of beer to my friends’ wedding that took place two weeks ago. Today I thought I’d finally write some tasting notes in case someone is interested in trying the recipes. I’m slightly more happy with the Pale Ale, but I have brewed the recipe (or at least variations of it) several times. Both beers were good though! Let’s start with the Dunkel!


The beer pours with a light brown color and it is slightly hazy. The color was a bit lighter than I expected, but then again I didn’t use that much roasted malts in this. A cream colored head is formed, but it collapses quite quickly leaving drapes of lacing along the glass. The appearance is okay. I’m not really sure why it hasn’t cleared despite the 2 months it was lagering in the keg at 0C. The aroma features some light roastiness (hints of dark chocolate), dark fruits, dark malt bread, and syrup/molasses. The aroma is quite clean and promises a malt-forward flavor. The taste is similar to aroma, with a light roastiness and bready malt tones dominating. Towards the end, a slight yeasty fruitiness joins in together with some grassy hops. The finish is quite dry and lightly bitter. Unfortunately the flavour is slightly boozy/solventy as well, which hints that the fermentation was not perfect. It was fermented in a temperature controlled fridge, so perhaps I underpitched or underaerated. The body is on the light side and the carbonation level is a bit too high. It is easy to drink and quite refreshing though. All in all, I’m quite happy, but you can definitely tell that the fermentation didn’t go perfectly. I’ll have to try again next winter.


The Pale Ale was more to my taste, and it was also the beer that got most compliments at the wedding (it also ran out first). It pours with a quite clear golden-amber color (similar to Sierra Nevada’s Pale Ale). This was slightly hazier at the wedding, so it cleared up nicely during two weeks in the fridge. A fluffy white head is also formed during the pour, and it collapses slowly leaving lots of lacing along the glass. A really nice appearance! There is lots of citrus (especially grapefruit), resin and grassy herbs in the aroma. As you can guess, it is very hop forward. The aroma is otherwise very clean and promises a really tasty beer. The taste begins with a slightly sweet caramel cookie flavor, and it is quickly joined by grapefruit and ‘tropical fruit’ hop flavors. Very fruity. The finish ends in a moderate bitterness, that has a slightly grassy and herbal quality to it. Maybe from the dry hops? I remember the beer being grassier at the wedding, so maybe it has cleaned up during these two weeks. The flavor is also very clean, and you can tell the fermentation went well. The beer has a medium body and carbonation level, and is very easy to drink and really refreshing. A really nice APA that suits my taste buds perfectly. It went quickly during the wedding so it seemed like I wasn’t the only one who liked it!

The labels to the beers were designed by my lovely wife ♥

Homebrew: Wedding APA

Last weekend I attended my friends’ wedding (thanks for the great party!), to which I had brewed two batches of beer. The first was a Dunkel and the second an American Pale Ale. I brewed the APA back in November with my brew mate, but I seemed to have forgotten to post the recipe and brewday notes. As I wrote in the Dunkel post, I’ve noticed that the most popular beers during these kinds of events are balanced and easy-to-drink beers. American Pale Ales with a relatively mild bitterness seem to be especially popular, so I used the recipe of my own Wedding APA as a base for this beer.

The malt bill was kept simple, with Maris Otter, Munich and Carapils. For the hops, I used up some opened bags of American hops from the freezer. The bitterness ended up a bit on the high side, but it was still suitable for the style. For the yeast I chose my ‘house yeast’ WLP002, which flocculates well and leaves a nice flavor profile. The brewday went quite smoothly and the beer was really popular during the wedding! I will be posting tasting notes of both the beers in an upcoming post!

[beerxml recipe= metric=true cache=-1]

Tasting Impressions: Schwarzbock from 2013

I found a couple of bottles of homebrewed Schwarzbock from 2013, and I decided to see how it had developed during two years in bottle. This one ended up at an ABV of 6.8% and with a final gravity of 1.020, so a bit lighter than what was originally planned. I remember this one being very tasty when fresh, so let’s see how it tastes now!schwarzbock

The beer pours black and with a fluffy tan-colored head (it looks a lot lighter in the picture below). If you hold the glass against the light, you see that the beer actually has a dark ruby color (and is crystal clear). As the head collapses, it leaves patches of lacing along the glass. A nice appearance! The aroma is really nice as well, and it features a good combination of chocolate-like roasted tones, together with dark fruits and caramel. There is a slight alcohol note in the aroma as well, even though this is only 6.8%. The flavor is mostly roasty as well, with tones of dark chocolate and ash dominating. Behind this roast, there are tones of malt bread, biscuits and caramel that balance out the flavor. There are not many hop-derived flavors, but that was expected based on the recipe and the beer age. The finish has a moderately light bitterness though. The finish is quite dry as well, which adds to the perception of a relatively light body. This is quite a difference to the sweet and strong imperial stouts. The moderate carbonation level gives the beer some more mouthfeel though. It is quite easy to drink, and it has aged very well! Overall, a very nice beer that I would definitely brew again!

Homebrew: Fresh Hop Ale

I collected this year’s hop harvest two weeks ago, and today we finally brewed a beer with them. This is the first time I’m using homegrown hops, so am really looking forward to tasting the final beer! Technically, this wasn’t actually a fresh hop ale, since I dried the hop cones before using them – but I’ll call this a fresh hop ale anyways. Since I’m not sure about the alpha acid content of these hops, we decided to use them only as flame-out hops, and instead use some Herkules at the beginning of the boil. This way we will hopefully extract the maximum aroma out of them as well. The homegrown hops weren’t very aromatic, so I’m expecting mostly grassy flavors and less of the typical citrus and pine resin. But hopefully I’ll be positively surprised! The post-boil wort had a slight perfume-like tone, which might have been hop-derived. For the malt bill, we went with a very simple 90% Maris Otter and 10% Carapils to an OG of around 1.050. This should let the hops shine (if they do). For the yeast, we used a really fruity ale strain that I’ve developed at work (more about that in a future post). I’m hoping it will compliment the hops, and make for a refreshing and crisp fresh hop ale! We will see in a couple of weeks!


This was the first time we brewed at our ‘new’ basement brewery (we moved there 1.5 years ago – yes, we’ve been extremely slow with the renovation), and I’m happy to say that everything went really smoothly. We were done in 5 hours and 30 minutes, reached almost 70% brewhouse efficiency, and the ventilation system (a really powerful inline exhaust fan) worked amazingly well. Looking forward to brewing a bit more regularly from now on!

[beerxml recipe= metric=true cache=-1]

Homebrew: Wedding Dunkel

Time for another wedding beer. This time not for my own wedding, but for two of my friends’ wedding. The groom requested one dark and malty beer (the wedding is in January, so that would fit with the cold weather) and one pale and fresh beer. I’ve noticed that the most popular beers during events, where the majority of the people are not ‘beer nerds’, are balanced and easy-to-drink beers. American Pale Ales with a relatively mild bitterness seem to be especially popular, so I thought I’d go with a remake of my own Wedding APA for the pale and fresh beer. For the dark and malty beer, I decided to go with a dark lager.

I haven’t brewed many dark lagers before, but decided to go for a malt base dominated by Maris Otter and Munich malt. To this I added hints of Chocolate and Dark Crystal malt to give some color and flavor. I kept it simple with the hops, and decided to go with Tettnang at moderate amounts to a fairly low IBU. For the yeast I chose to use W-34/70, which is my favorite homebrew lager yeast because of the ease-of-use (just sprinkled two packs on top of the 21 litres of wort) and the clean and crisp flavor profile. The brewday went extremely smoothly, and 21 liters of wort are now fermenting strongly at 12C. The aroma coming from the airlock is really nice, which is always a positive sign! The wedding is in about three months, which will mean I will have some time to lager the beer once it has finished fermenting.

[beerxml recipe= metric=true cache=-1]

Homebrew: Bavarian Hefeweizen

I’ve again been lazy and haven’t updated the blog for a while. There hasn’t been that much interesting to post though. About three weeks ago I brewed a Bavarian Hefeweizen for a friend, and today I decided to pop the first bottle as quality control. The recipe was really simple, with the malt base being 60% wheat malt and 40% pale ale malt. I hopped with Tettnanger to a modest 16 IBU, and fermented the wort with WLP380, supposedly the Schneider Weisse yeast.

[beerxml recipe= metric=true cache=-1]



The beer pours with a hazy golden-yellow, almost grey, color. A fluffy white head is formed, but it collapses a bit too quickly for a Hefeweizen. A typical wheat beer appearance. The haze is both yeast- and protein-derived as it was quite clear before I put it in the fridge.

The aroma is typical Hefeweizen, with tones of cloves and banana. The spicy 4-vinylguaiacol dominates the aroma profile, but there are lots of fruity esters present as well. The aroma is quite one-dimensional, but I guess it fits the style quite well.

As with the aroma, the flavour profile is dominated by spicy phenols and fruity esters. The amounts of esters and higher alcohols almost go a bit too far as I get hints of solvent as well. On the other hand, it has only been three weeks since pitching, so these will probably subdue a bit with some time in the bottle. There are some malty and doughy tones hidden in the background, but I can’t detect much hop presence at all. As it should be in a Hefeweizen. The carbonation level is high and the body quite light. Refreshing and quite easy to drink.

Overall this is an okay Hefeweizen. I’m not that big fan of the style, so I have a hard time judging how successful this beer is. It is still very young, so it will probably change a bit with more time in the bottle. There are definitely a lot of esters and phenols present, as it should be, but there might even be a bit too much of them at the moment. Perhaps this could have been fermented at a slightly lower temperature?

Small Update

Just thought I’d write a short update on the recent beers I brewed for my upcoming wedding. They are all tasting really nice, which I’m happy about. Here are some short tasting notes:

Wedding Pils – Dry finish, grainy malts, and a floral hoppiness that ends with a nice bitterness.

Wedding Blond – Lots of spicy phenols and fruity esters from the yeast. Not my favorite style, but this is quite a nice Belgian-style ale.

Wedding Hybrid – Lots of hop aroma combined with fruity esters. A slight hint of spicy phenols in the flavor. APA meets Wit. I like!

Wedding APA – Citrus and floral hops mainly that end in a moderate bitterness. Some maltiness as well, and not a completely dry finish.

Wedding IPA – Lots of citrus and tropical fruits from the hops together with a huge bitterness. A really successful IPA!

Also, here is a progress picture of the ‘bar’ I’m building for the wedding. Five homebrews will be available on tap. I still need to paint it and build a drip tray, but it should be ready in a couple of days. Really looking forward to testing it!


Homebrew: Wedding IPA – American IPA

Yesterday I brewed the fifth and final batch of beer for my wedding in August (see previous posts for the Wedding Pils, Wedding Blond, Wedding Hybrid, and Wedding APA): an American IPA loaded with hops and fermented with Conan. I’ve brewed a slightly similar recipe before (see here), and while it was a nice beer, it ended up a bit too sweet with WLP007. This time I’m changing up the hop bill slightly based on what I have in the freezer, and I’ll be fermenting the wort with Conan. I’m hoping for a hoppy and bitter IPA, with loads of fruity aromas from both the hops and the yeast.

The malt bill is similar to the APA I brewed last week, and it consists of Maris Otter, Munich, CaraPils and CaraAmber.  I mashed quite low (63C) in order to get a very fermentable wort. I’ve used Conan a couple of times before and I’ve ended up with around 78% attenuation. I aimed for an original gravity just below 1.070, in order to get a beer with around 7.5% ABV. For the hops, I chose to bitter with Herkules (using up the last from a 100g bag), added some Cascade and Centennial during the boil, and at flameout I added even more Cascade and Centennial together with some Amarillo. The bitterness levels should be around 70-80 IBU, depending on how much the whirlpool hops contribute. I pitched a 1.5L starter of Conan after I had cooled the wort down to around 20C. I placed the fermenter in my fermentation fridge and set the fermentation temperature to 19C. I checked the fermenter 24 hours later, and it was fermenting violently with krausen coming out of the airlock. After a quick clean-up things were looking good again. Man it was smelling good inside the fermentation fridge!

[beerxml recipe= metric=true cache=-1]