Bock & strong lager
Eisbock
A doppelbock concentrated by partially freezing it and removing the ice, intensifying malt, body and alcohol together.
- Strength
- 9–14% ABV
- Bitterness
- 25–35 IBU
- Colour
- Deep copper to black
- Serve at
- 10–14°C
Also known as ice bock.
Freeze concentration works because water freezes before ethanol does. Removing the ice leaves everything else more concentrated — not only the alcohol but the malt, the sweetness and any flaw present in the base beer.
The technique is legally constrained in some jurisdictions, since in others it is regarded as a form of distillation. That is a regulatory question rather than a brewing one, and it varies.
The concentration is indiscriminate, which is the practical warning: any harshness, any solvent note, any flaw in the doppelbock underneath comes through amplified rather than smoothed. A good eisbock therefore says as much about the base beer as about the technique. Treat it as a digestif — a small measure, served warm enough for the dark fruit to open.
Questions this page answers
- what does eisbock taste like — How it tastes
- eisbock abv — Measurements
- eisbock food pairing — What to eat with it
- eisbock serving temperature — Serving
- how long does eisbock last — Freshness and storage
- styles similar to eisbock — If you like this, try
- how to brew eisbock — How it is made
- what beer is an example of eisbock — Beers to try
- is fusel alcohol normal in eisbock — Characteristics that may be expected here
How it tastes
BeerHQ’s own comparative scale, not a measurement. Each bar is a range because a style is a span of real beers rather than one beer.
Appearance and character
| Colour | Deep copper to black |
|---|---|
| Clarity | clear |
| Head | Tan, small, short-lived |
| Fermentation | Bottom-fermented (lager). Fermented cool with Saccharomyces pastorianus, which settles out, then conditioned cold. The cooler process suppresses yeast-derived fruitiness, leaving malt and hop character exposed. |
| Origin | Germany |
Measurements
Conventional ranges published by style bodies, not a specification. IBU measures iso-alpha acids in a lab and does not track perceived bitterness — compare it against the sensory scale above rather than reading it as a flavour rating.
| Measurement | Typical range |
|---|---|
| ABV | 9–14% ABV |
| IBU | 25–35 IBU |
| Colour | Deep copper to black — 18–30 SRM, 35–59 EBC. |
| Original gravity | 1.078–1.120 |
| Final gravity | 1.020–1.035 |
| Carbonation | 1.6–2.2 vol CO₂ |
Classified by BJCP-2021 as Eisbock (exact fit). BeerHQ maintains its own taxonomy and records how it maps onto others rather than adopting any one of them.
What goes into it
| Malt | Munich malt, Melanoidin malt |
|---|---|
| Yeast | German lager yeast |
Serving
Freshness and storage
Eisbock is typically at its best 12–60 months after packaging, and time is working for it rather than against it.
Rewards age. Given cool, dark, upright storage this develops depth most drinkers would call an improvement. Buy two and compare.
- BeerHQ records this style as one that develops rather than declines with time.
Very stable. Alcohol and density protect it, and it develops slowly over years.
What changes with time
- Oxidation. Reaction with oxygen, producing wet cardboard and sherry notes in pale beer and dark-fruit depth in strong dark beer. Months to years, depending on packaged oxygen and temperature.
- Deliberate ageing. Keeping a beer on purpose, accepting some oxidation because of what it develops in return. One to ten years for suitable styles. Most beer is not suitable.
- Staling. The general, gradual loss of freshness that affects all beer, accelerated sharply by warmth. Months, and roughly twice as fast for every 10 °C warmer.
In the package
- Brown glass bottle — No format-specific concerns beyond the general advice above.
- Aluminium can — No light can reach the beer, so lightstrike is impossible in this format.
- Keg — No light can reach the beer, so lightstrike is impossible in this format.
Old beer tastes worse; it does not become dangerous. Ethanol, low pH, hop compounds and the absence of oxygen make packaged beer hostile to the organisms that cause foodborne illness. The exception is a compromised package — visible mould at the closure, a pierced or rusted can, a lifted cap — which is a reason to discard the beer regardless of its age.
Guidance, not an expiry date. How a beer is stored matters more than the date printed on it, and staling roughly doubles in rate for every 10 °C. See storage and freshness for the full model.
What to eat with it
- Affogato
Chocolate, coffee and caramel notes in the beer are the same flavour family as the dessert, so the two read as one thing rather than two.
- Chocolate
Chocolate, coffee and caramel notes in the beer are the same flavour family as the dessert, so the two read as one thing rather than two.
- Soy-glazed dishes
Deep malt character matches the savoury weight of the dish instead of sitting apart from it.
- Tiramisu
Chocolate, coffee and caramel notes in the beer are the same flavour family as the dessert, so the two read as one thing rather than two.
- Brownies
Chocolate, coffee and caramel notes in the beer are the same flavour family as the dessert, so the two read as one thing rather than two.
- Caramel desserts
Chocolate, coffee and caramel notes in the beer are the same flavour family as the dessert, so the two read as one thing rather than two.
Beers to try
Widely-known examples BeerHQ carries as reference points for this style. Not a recommendation list and not ranked — these are the beers that make the category concrete.
If you like this, try
Doppelbock
The base beer this is concentrated from.
Suits you if: You like Eisbock but want more nutty. Reason not to: Weaker than Eisbock, which may not deliver the intensity you are after.
English barley wine
Comparable strength and malt density from a different tradition.
Suits you if: You like Eisbock but want less bread & biscuit. Reason not to: Noticeably less bread & biscuit than Eisbock, which may make it feel thin by comparison.
Bock
Same family — both are Bock & strong lager beers.
Suits you if: You like Eisbock but want less sweetness. Reason not to: Weaker than Eisbock, which may not deliver the intensity you are after.
Helles Bock
Same family — both are Bock & strong lager beers.
Suits you if: You like Eisbock but want less caramel & toffee. Reason not to: Noticeably less caramel & toffee than Eisbock, which may make it feel thin by comparison.
Wee heavy
Comparable sweetness, body, alcohol warmth — the things you are probably drinking Eisbock for.
Suits you if: You like Eisbock but want less bread & biscuit. Reason not to: Weaker than Eisbock, which may not deliver the intensity you are after.
Compare with
- Eisbock vs Bock — The main difference is yeast fruitiness (esters): Eisbock has noticeably more of it than Bock. Eisbock also leads on chocolate & cocoa; Bock on roast and nutty.
- Eisbock vs Helles Bock — The main difference is caramel & toffee: Eisbock has far more of it than Helles Bock. Eisbock also leads on yeast fruitiness (esters) and chocolate & cocoa; Helles Bock on hop aroma.
- Eisbock vs English barley wine — The main difference is bread & biscuit: Eisbock has far more of it than English barley wine. Eisbock also leads on chocolate & cocoa; English barley wine on hop aroma and nutty.
- Eisbock vs Doppelbock — Eisbock and Doppelbock are closer than the comparison suggests. The measurable differences are small — nutty is the largest of them — so tradition, strength and what each is brewed for will tell you more than the flavour axes do.
Characteristics that may be expected here
Each of these is treated as a fault in most beer, and in this style it can be part of the character. Intensity and context decide which: a trace that suits the style and an obvious, dominating version of the same thing are not the same finding. Follow the link where you want to work out which one you have.
Fusel alcohol
Strong beers are expected to show alcohol warmth, and a smooth warming character is part of their appeal. The fault is harshness rather than presence: pleasant warmth is round and integrated, while fusel character is sharp, solvent-like and burns.
Faults to watch for
- Fusel alcohol — Harsh, solvent-like alcohol heat from fermentation run too warm or under stress — distinct from the pleasant warmth of a strong beer.
- Solvent — A solvent-like ester that reads as pear drop at low levels and as nail varnish remover at high ones.
How it got here
Eisbock is made by freezing a doppelbock and removing the ice, which is water, leaving a more concentrated beer behind. The practice is associated with Kulmbach in Franconia, and the story usually told — that it was discovered when barrels were left out in the cold and froze — is the kind of origin anecdote that is repeated far more often than it is documented.
How it is made
The steps that shape this style in particular, rather than the ones every beer goes through.
- Lagering — Store beer cold for an extended period after fermentation to clarify it and produce the clean, rounded character lagers are named for.
- Freeze concentration — Concentrate a finished beer by freezing it and removing ice, raising strength and body without further fermentation.
Sensory levels are BeerHQ’s editorial abstraction, described as None–Very high on a six-point scale. Measurements are conventional style ranges. Last reviewed 2026-08-15.
Evidence
What BeerHQ knows about this, and how. Every statement carries the state of the evidence behind it rather than being presented flatly as fact.
On Solvent
Acetate esters — ethyl acetate among them — are made by the yeast rather than extracted from anything. Acetyltransferase enzymes join acetyl coenzyme A to an alcohol, so the ester a beer carries depends on which alcohols the fermentation produced.
Checked against the source
Source: Lilly et al., "Effect of Increased Yeast Alcohol Acetyltransferase Activity on Flavor Profiles of Wine and Distillates" (2000), abstract and introduction (Appl Environ Microbiol 66(2):744–753)
On Solvent
Raising fermentation temperature or wort gravity increases acetate ester production, which is why the same yeast gives a clean beer in a cool fermentation and a solvent-like one when it runs hot.
Checked against the source
Source: Svedlund et al., "Fruits of their labour: biotransformation reactions of yeasts during brewery fermentation" (2022), section on acetylation of 3-mercaptohexanol (Appl Microbiol Biotechnol 106(13–16):4929–4944)
On Fusel alcohol
Fusel alcohols are a fault only at concentration: at high levels they impart off-flavours, while at low levels they and their esters are an essential part of the flavour and aroma of fermented drinks.
Checked against the source
Source: Hazelwood et al., "The Ehrlich Pathway for Fusel Alcohol Production" (2008), Introduction (Appl Environ Microbiol 74(8):2259–2266)
On Fusel alcohol
The higher alcohols behind fusel character are formed by yeast from amino acids through the Ehrlich pathway: the amino acid is transaminated to an alpha-keto acid, which is decarboxylated to an aldehyde and then reduced to the alcohol.
Checked against the source
Source: Hazelwood et al., "The Ehrlich Pathway for Fusel Alcohol Production" (2008), Initial transamination reaction (Appl Environ Microbiol 74(8):2259–2266)
On Lagering
Carl von Linde’s mechanical refrigeration, first installed in a brewery in the early 1870s, freed lager production from dependence on natural ice and cold cellars.
Backed by a source
Sources: Beer: The Story of the Pint — print; The Oxford Companion to Beer — print
On Lagering
Mechanical refrigeration from the late nineteenth century removed lager brewing’s dependence on cold cellars and natural ice, allowing it to be produced year-round and anywhere.
Backed by a source
Sources: Beer: The Story of the Pint — print; The Oxford Companion to Beer — print